Roofing materials – what choices do you have? Part 2

Let’s have a look at the typical products available in the Montreal area.

Asphalt shingles in all their various forms, constitute anywhere from 50% to 95% of the installed roofs (for sloped residential roofs) with the proportion depending on the area of the city or region.  They are the cheapest form of roofing, are readily available from any number of sources, and are the easiest to install.  They also are not waterproof, can easily blow off (if not properly installed), and usually last from 10-15 years.  The exact kind of weakness they show depend on the type and brand of shingle, but in general, even with good installation practice and proper preparation, they usually don’t last much beyond 18 years.

Tar and gravel roofs are quite common in certain areas of the city, and are found on flat and lower sloped (2:12 to 3:12) roofs.  They were very inexpensive to install, and generally last 20-30 years.  However, given that they are “built-up roofing” made from successive layers of tar paper embedded in roofing tar, they depend on good installation practice both in the laying down of the basic material, and in the flashing details at the roof perimeter and any penetrations.  At this time, the number of companies that continue to do this work is much less than before, and they tend to be large commercial outfits.

 Membrane roofs are now seen more and more, replacing the tar and gravel coverings on low-slope roofs.  These membranes are of different construction and use different materials, but the most common is a form of modified asphalt sheet (usually two-ply), that is installed in overlapping layers.  There are different installation methods, with some being glued down, and others requiring open flames to melt and seal the layers.  The latter is called “torch-on” membrane, and should be installed only by insured craftsmen.  Durability and effectiveness depends very much on the installation skill and detailing, but a well-installed membrane roof should last about 20-25 years.

 Metal roofs were very common in our region before asphalt shingles became the common material, partly because of our snow loads – they allowed the snow to slide off and reduce the load on the roof.  Since those times, metal roofs evolved in a dramatic fashion, creating products such as standing seam roofs, steel, aluminum and copper shingles, various profiles of metal panels that resemble clay tile, or wood shake, or architectural asphalt shingles.  The roofs range from very cheap (generally thin screw-through panels) to very expensive (hand-made copper or stainless steel coverings).  Most metal roofs come with 50-year (give or take) product warranties, and if properly installed, can be expected to last over 100 years.  On the other hand, the choice of which metal product is most appropriate for a given situation is something that many homeowners just don’t have the knowledge to make, and are very susceptible to the salesperson pitch.  Proper installation also plays a very important role in the actual longevity of the products, and this is also an area where most people just don’t have the experience to ask the right questions.

Wood or cedar shingles used to be very common roofing materials, but with the disappearance of first-growth cedar, the prices have skyrocketed, and these products are available usually only on high-end homes.  Being a natural product, they have a unique appearance, but also require a certain amount of maintenance and care to reach their potential life.  They have to be installed in a manner that allows them to shed water and to drain well, so that there is little chance of trapped water promoting rot.  Installing these is a very skilled trade, and there are only a few contractors in our region that do a proper job.

Slate is a relatively common material for roofing, especially in areas like Westmount and Outremont.  It is a beautiful, historic covering, and properly installed will last well over 100 years.  However, both the material, and the skilled labour needed to install these is quite expensive, so these are now found only on high-end homes that can handle the weight, and whose homeowners can afford to pay for the maintenance.

Clay tile (and its cousin, concrete tile), is a very common material in many parts of the world, and is found also in our region.  However, in addition to the weight, our frequent freeze-thaw cycles wreak havoc on any tile that has a crack forming on it.  In addition, most homes are not designed to hold up the amount of static weight that such a roof will represent.  Maintenance is also an issue, since these are relatively fragile, and should not be walked on.  We find that homeowners often choose to replace these with metal products that have a similar appearance, without the fragility of true clay.

There are newer materials coming onto the market, including fake slate made from recycled plastic and rubber, and fiberglass panels.  Time will tell whether their initial attractiveness will last or whether the UV exposure and temperature extremes will cause damage.  Earlier versions of these products came onto the market and were withdrawn after frequent failure.  Maybe the new generation will finally get the mix right.

One important consideration in choosing a roofing material, is the life-cycle cost.  What IS the actual duration of the “trouble-free” period for each type of material (and the method of installation)?  Since failure usually starts at the weakest part of the system, it is important to know what that part is, and to do the required maintenance so that part can last as long as the rest of the roof system.

An example of the type of problems that can occur is an asphalt shingle installation over an OSB (Exposure Type 1) deck.  Even when properly installed, some shingles will start letting in water (via the nail holes) in as little as eight years.  Once that water starts entering the OSB decking, the glue starts to deteriorate, and the OSB panel starts losing strength and integrity.  The shingles may still look good on surface inspection, but the seepage pattern visible from the attic will tell otherwise.

A very common waterproofing technique is to use caulking in “waterproofing” various roof joints and penetrations.  The more common caulking formulations lose their resiliency and adhesion in as little as five years, even when properly installed.  Is it a coincidence that most installation warranties (on asphalt shingles) only last 5 years?  The way around this is to build the roof system so that the caulking is more or less cosmetic, with the real waterproofing happening behind/below the caulking.  Ah, but THAT takes more expensive materials, and more labour to install, and besides, it can’t be seen, so why bother?  This detail work is the difference between a waterproofing joint that will last 5 years (more or less) compared to a waterproofed joint that will last 20-30 years or more.

Therefore, when looking at the life-cycle cost, it is important to consider both the material AND the way the product is installed.  Certain materials (like asphalt shingles) are more susceptible to other deficiencies in the roofing system, like improper insulation and/or ventilation.  In addition to “pure” life-cycle costs of the roofing system only, you also need to consider the costs associated with the risks of failure.  For example, if the roofing system fails gradually over time, and there is persistent low-level leakage into the roof decking, then this may be a minor issue if the decking is solid wood, but may be a major issue if the decking is OSB( exposure Type 1).  If the house in question also has ice damming issues (due to insufficient insulation and ventilation), then it is almost guaranteed that there will be serious roofing issues and damage UNLESS the proper preparation and waterproofing was done.

Therefore, in order to make an intelligent purchasing decision when choosing among the various roofing materials available, it is important to also understand the current weakness of YOUR specific roof to know what preparation, waterproofing, and additional work such as ventilation and insulation improvement is needed in order to achieve the promise of what the roofing system could deliver.  Since changing a roof is a major expense for most people, shouldn’t you know that you’re getting the best product and installation for the money you will need to invest?

If you’re not sure about the best fit for your situation, contact me.  We’ll examine your current situation,  determine which factors we need to take into account, and review the options you have.  Now you will be in the best position of knowing what needs to be done and how it should be done, without worrying about whether short-cuts have been taken.  No point in wasting your hard-earned money, and putting your most important investment at risk!

(c) 2014 Paul Grizenko

Roofing materials – what choices do you have? Part 1

There are plenty of marketing pieces on the web and elsewhere touting this material or that material as the “Best” or the “Most-Cost-Effective”, or the “Best Performer”.  This post isn’t going to be one of them.  Rather, I’ll direct your attention to the gap between the consumer expectations (based on marketing claims), and the actual performance.  This isn’t to say that the manufacturers are lying through their teeth, but more that they are trying to encourage you to associate certain properties with their product that may not be justified by test results.

The first thing to recognize, is that each material has both strengths and weaknesses.  There is a set of conditions for which the product is superbly suited.  There is another set of conditions under which its performance will be entirely unsatisfactory.  Roofing materials are part of the building envelope, and as such, are subject to the rules (the building code) which govern the minimum standards for construction.  Certain materials have specific tests that define certain properties or performance criteria of these materials, and the building codes usually reference the minimum performance that under those tests is acceptable.

Manufacturers develop installation instructions and guidelines to ensure that their products will not be placed in situations where their weaknesses are exposed.  Therefore, if the product is installed in conformance with the guidelines, then its behaviour should be in line with the manufacturer’s claims.  This puts the emphasis on proper installation – where it is assumed that the installer knows the weaknesses of a product, and if the product is installed in a situation where the weaknesses will show up, to provide the appropriate additional protection to minimize the weaknesses.

A common example of this is the use of asphalt shingles on roofs where ice-dams can form.  Asphalt shingles are designed to be a cheap, reasonably-long-lasting cover for roofs, and work by shedding water.  To work well, they have to be installed on a slope that is sufficiently pitched to allow the water to run off freely, to be secured appropriately, and to have enough roof heat to allow the tar strips to bond the top and bottom layers of the shingles together.  They are NOT designed to be waterproof.  If a roofer installs them on a roof where he knows that there is a history, or likely possibility of ice damming, he knows he needs to install additional waterproofing (in the form of an ice-and-water shield membrane) to compensate for the fact that the shingles will let water in.  Depending on the severity of the underlying issue, additional measures may also need to be taken to ensure that the weakness of asphalt shingles in this situation do not lead to an immediate problem.

Most homeowners are obviously not aware of the subtleties of proper installation, the nuances of “appropriate use”, and the different ways things can fail.  Since their source of information is usually the glossy brochures of the manufacturer, their perception of what they are buying, may be quite different from the reality.  Let me illustrate.

Slide 1 - Benefits

Above is a diagram illustrating a collection of benefits that a particular product can give.

Slide 2 - Benefits and weaknesses

Real-world products also have weaknesses of various kinds.  Often the “Weakness” is visible only under certain situations.  An example of this would be the ability of a smooth metal roof to shed snow.  If you WANT the snow off your roof, then this is a benefit.  If, on the other hand, the falling snow can damage property or cause injury to people, then this is a weakness.

Slide 3 - Benefits according to Marketers

Marketers present their products to be as attractive as possible, and try to associate all kinds of feelings and projected desires so that consumers are moved to buy the product.  There is a lot of subliminal messaging going on, both through the text and the imagery used, to create a favourable impression of the product.  It’s not to say that the marketers are lying or misrepresenting their products – but they often set up the ad so that we infer more than they actually say or claim.  Examples of this would be “green” claims, or images with happy families, or beautiful couples in front of something unrelated.  Another method is to use references to warranties to imply a durability that is not actually claimed in either the marketing literature or in the warranty.

Slide 4 - Benefits according to Consumers

Of course, most people looking at advertising and marketing material end up with an impression, and link that with a set of assumptions, giving a perception of the product that may be much more favorable than the product deserves.  If this is a product presentation by a salesman/woman, then by now the process has become entertainment, with suspension of disbelief, and willingness to dream being part of the mix.  Salespeople love it when it comes to this – because people work hard to make their dreams come through, and why let a few inconvenient facts get in the way?

Slide 5 - Reality

In the end, you’re still getting only the actual benefits and weaknesses that the product inherently has.  As noted before, the knowledge, skill, and care of the installer go a long way towards minimizing the weaknesses, and maximizing the benefits.

How does this impact our decisions as far as selecting the products for our roofs?  Tune in for another post.

(c) 2014 Paul Grizenko

Question to my readers…

When I started this blog, I was hoping to have a conversation with people who had questions about a somewhat esoteric subject (roofing and related subjects) on which there is much misinformation.  Granted, it is not something that is top-of-mind for many, but when it becomes necessary to do something, time is usually not on your side, and there is a lot of pressure to get something done to avoid or prevent further damage.  However, the underlying processes of gradual deterioration have been occurring for a long time before the situation became acute.  The posts in this blog have several purposes:  to share knowledge and experience, to (hopefully) correct misinformation, to educate, and for those people in my service area, to help them resolve issues and concerns.

The question or questions that I put to you, my readers are as follows:

  • What issues about the roof systems do you find confusing?
  • What kind of things would you want to read about more on this blog?
  • What kind of information are you seeking that you’re not finding?
  • What were you looking for when you came across this blog?  Did the information found here help you?
  • What issues would you like to see addressed?

Please note that I will not  make specific product  recommendations, because in general, most of the products on the market are excellent, as long as they are used as intended and are installed by experienced and conscientious workers.  On the other hand, all products are part of a system, and rely on other elements to work properly in order that they do their intended job.  Some systems are designed better than others, and a discussion of how the designs compare is probably within the scope of this blog.

Please use either the Contact Us form, or add your comments to any of the posts or articles that you find interesting.  I look forward to having a meaningful and mutually productive conversation!

What is condensation?

If you listen to some people, you’d think that “condensation” is the satanic miasma that descends upon the undeserving, punishing them for sins committed in prior lives (or capriciously,  for no reason whatsoever).  In the field of roofing, roofers will look upon an afflicted home and suggest various remedies, many of which are no better than burning chicken entrails under a full moon, or uttering incantations banishing the spirits from the crevices in which they took refuge.  It is also quite common for all kinds of building mischief to be blamed on “Condensation” hence informing the suitably-impressed home-owner that they are in the presence of a superior intelligence.


Continue reading

Planning for a new (re-) roof? A checklist of things to consider.

It’s winter, and you’re thinking about perhaps getting a new roof in spring.  Why?  Well, it could have been looking a bit worn and shabby in fall.  Perhaps you’re tired of living with the ice dams and icicles.  You could have been in the attic and noticed some condensation on the nails and wetness on the wood.  Or you may have been “stretching” it out as long as possible, and you’re getting afraid that this time it really won’t hold up any more.

So, let’s pick up the phone (or more likely, turn on the computer) and get three estimates.  That’s what we are usually told to do as a prudent way of getting a quote.  However, I will suggest to you that this approach is flawed, partly because it depends on the people doing the quoting actually caring about whether they will be doing the right thing for you (or not).  If you are lucky, you will get three knowledgeable, experienced and ethical contractors who will evaluate your situation, determine your needs, and tailor a solution appropriate to your situation.  Uh huh.  What do you think your chances are? 

What is somewhat more likely is that you’ll get a salesperson who needs to fill his or her quota.  They may (or may not) know their product, they may (usually not) know how the product is installed and they may (but almost certainly not) know what kind of things can go wrong.  Will they do a proper inspection?  Will they try to understand what is working (or not) in the current installation?  Will they pick an appropriate product for the situation or will they sell the product they have (whether it is appropriate or not)?  How will you know if the company will do the necessary preparatory work?  Unless you’ve done some homework ahead of time, you don’t.

Let’s review what you need to know.

The first step is to know what you have – that takes an inspection.  (see the blog post about inspections:  If you’re not sure of what you need to be looking at, the article “Components of a sloped roof system” ( may  help.  If you’re not comfortable doing such an inspection, you could consider hiring us (see the “Contact Us” form here:

The rest of the process is described in the article “How to get a good quote for your roof” ( located in the Pages/Articles/ section.

When it comes to choosing the contractors to give you the quotes, you want to use those who have the track record of good performance of work.  To find them, you could use the information in the article “How to choose a contractor in Quebec: (

If you go through the articles I referenced, you’ll find that there’s quite a bit of homework to be done before you choose the best quote.  And that’s the point – it may look like you’ve got lots of time to spring, but doing the homework takes time, and the good guys that you’ll want to hire are going to be fully booked by the time the season starts.  Better put this on your to-do list. 

(c) 2014 Paul Grizenko

Ventilation for roofs – why, what, when, where, how (instead of who)

Ventilation is like vitamins – everyone knows you need some, but often don’t know why.  This post discusses some aspects of ventilation that  homeowners should know about.


Ventilation is used to:

1)  reduce the heat build-up in the attic and

2)  reduce the moisture levels in the attic.

The first helps reduce the cooling requirement in summer, and reduces the snow melting (which can lead to ice dams) in winter.

The second helps in keeping the attic relatively dry and thus minimizes the possibility of condensation, which in turn reduces the support for rot and mold.  If the roof system suffers from persistent, if low-level leakage (as often happens with older roof coverings), this ventilation also helps dry out the leakage.


Ventilation is the movement of air through an enclosed space.  Ventilation can be passive (working on gravity and density only) or active (moved by a fan).  Active ventilation is usually NOT recommended for venting attics in cold environments due to the danger of pulling in moist air from the living space if the vapour barrier is not completely effective.

For passive ventilation to work, there needs to be an intake at a low point of the system (that’s the inlet for cold, dry air), an air channel through which the air can flow into the attic (where it picks up heat and moisture), and an outlet at the top of the structure (because warmed air is more buoyant than cold air, and rises to the top of the structure).  Since air has viscosity, the size of the openings determine the amount of resistance to the air flow.


Ventilation becomes particularly important in winter, when insufficient insulation often allows transfer of heat from the interior to the cold spaces.  If the vapour barrier is not very effective, there is also the danger of moisture from the living spaces to enter the cold areas and become condensation.  Good ventilation will help reduce both the amount of condensation, and the amount of heat transferred to the roof (where the heat can melt the snow and contribute to ice damming).


Ideally the intake ventilation is located along the lowest edges of the roof (which is where you will usually have the vented soffits), and the outlet ventilation is located at the top part of the roof, along the top ridge.  In between, you should have a minimum 2” air channel connecting the intake with the outflow.  The positioning of the intake and outlet vents is important to avoid the ventilation “short-circuit” which happens when multiple openings are present, and the air is drawn from the intake of least resistance, instead of the lowest ones.

Since many attics have limited space along the eaves for insulation, it is not uncommon to see insulation stuffed into the corners which ends up blocking the airflow from the soffits.  There are various products on the market designed to keep the airflow working.

The geometry of the roof, and the arrangement of interior space of the attic also affects the way the ventilation works.  Certain roof types and roof features are known to be problematic when it comes to ventilation, and require special measures to ensure correct function.


The ventilation product to be used depends on the roof type.  Simple pitched roofs are usually vented with soffit vents along the base of the roof.  Mansard roofs can have a more complicated requirement, and they usually use specialized vents to bring air into the upper portion of the mansard.  Outlet vents can be of various types, with gable vents, low-profile vents, turbines, ridge vents, and large vents like Maximums all having specific uses.

If venting is found to be necessary, but the existing structure doesn’t allow this, then it may be necessary to build a second deck with an air space between the old and new roofs.  Some metal roofs can be installed using the cross-bat system, which effectively accomplishes the same result.

It is very common for contractors selling “ventilation” to focus on the outflow vents and ignore the rest of the elements that make the ventilation effective.  In some circumstances, it is just not possible to arrange the correct ventilation, and other means need to be considered for achieving the two goals of ventilation.


There is a class of roof structures that do NOT need ventilation.  These are usually designed from the outset as sealed roof units where there is no need for ventilation as there is not movement of air into or out of the roof unit.  However, for these types of units, both the design and the execution of work need to be impeccable, to ensure that no moisture can enter the unit from either inside or outside.

Other stuff:

The ventilation should also be discussed together with vapour barriers, insulation, and the waterproofing on the outside of the decking.  They all interrelate in ways that need to be thought through if modifications to the system are being made.

Case Study:

This image shows mold growing on the underside of the plywood decking, despite the home having vented soffits and several large maximum outflow vents.

Example of mold buildup on decking due to leakage and poor ventilation
Example of mold buildup on decking due to leakage and poor ventilation

There were several issue with this house:

  • The insulation (fiberglass bats) were stuffed into the edges of the attic, blocking air flow from the soffits.
  • The insulation used in that area did not have enough resistance to heat to prevent loss of heat to the roof.
  • The consequent loss of heat caused large ice dams in winter.
  • The asphalt roof covering did not have enough Ice-and-water shield membrane along the eaves to prevent the water from the ice-dams to penetrate the roof covering to the wood.
  • There was not enough ventilation to dry out the moisture that was accumulating in the wood, supporting the growth of mold.
  • Due to the construction of the house and subsequent “improvements”, there was minimal space for adding either insulation or ventilation in affected areas.

There were several possible ways of ameliorating this situation.  They involved determining the areas where ventilation would just not be possible, and using certain techniques for preventing moisture buildup in those areas.  Other areas would have benefitted by using insulation with a much higher R-value per inch (given the limited space available), and by using certain products that would promote ventilation in tight areas.  A further improvement could have been made by using the appropriate water-proofing membrane in areas where the ice-damming could not be avoided.

(c) 2014 Paul Grizenko

Planned Obsolescence – Why doesn’t the stuff last?

Because, it’s not supposed to, silly.  We want our stuff to work until the novelty wears off, and then we want it to fail so that we can replace it without any guilt, for the next new thing.  This certainly applies to our electronic gadgets, much of our clothing, and even to our household furnishings and decorations.

So what’s wrong with wanting new stuff?  This approach is not limited to the small things, it can also be seen in our attitude to more expensive stuff, like cars, houses, and relationships.  We can accommodate this desire for novelty when the item is relatively cheap.  This desire, however, clashes with our desire for security (or risk-avoidance).  Cheap cars that broke down often and in fact were dangerous, have been replaced by cars that last longer, work better and are much safer.  People are now holding on to their cars an average of about 7 years, whereas in the past, this used to be as short as two years.

When it comes to homes, the older pattern of staying in the house for 20-30 years, has changed so that people now change their homes on the average once every 7-8 years.  Part of that appears to be due to increased workplace mobility, part of it is due to trading up, but there is also the aspect that people are using their home equity to finance their lifestyles and entertainment (as can be seen in the dramatic rise in home-equity loans and lines of credit).

This shortened time of residence has in encouraged people to think less of “long-term investment” in their property, and more about saleability (curb-side appeal, selling points like kitchens and bathrooms).  On the flip side, the amount of effort spent on ensuring the asset’s long-term value (ie, maintenance and upgrading of the fundamentals), has decreased, so that when things do start going wrong, they require much more effort to fix.  That in turn, prompts some people to sell, to avoid having to invest in major repairs, and leaving the expense to be new buyers.

Of course, the new buyers did not know the history of the home, and probably did not know what the true underlying state of the property actually is.  Home inspections go only so far in ferreting out the hidden defects.  This is one of the factors that prompted the Quebec government to institute a 10-year “hidden defect” law, allowing the new owners to sue the previous owners if a hidden defect (ie, a defect not disclosed in the sales documents) is found within 10 years of sale.  (check the links under the Links tab on the main menu).

Hidden defects can arise in a number of ways.  For instance, necessary regular maintenance may have been skipped, leading to a deterioration in the structure.  Alternatively, various changes and “improvements” may have been made without taking into account the way the house system does or should work, resulting in a defective operation of the system.  In other cases, hidden defects arise from the pattern of short-cuts taken by homeowners (and the contractors they hired) in carrying out essential work.

Returning to the starting theme of this post, a source of “hidden defects” is the performance of the roofing materials that are commonly installed.  Based on marketing and other influencers, homeowners often expect a product that is sold with a multi-year warranty to last the length of the warranty.  For example, many people believe that roofing shingles covered by a 30-year warranty will actually last 30 years.  There are other products that are sold with 50-year or “life-time” warranties, with the implication that once installed, this will be the last roof that the home will need.  (for links to the warranties of popular shingles sold in Quebec, check the links under the Links tab on the main menu).

The reality is somewhat different.  For various reasons, it is common to see roofs needing replacement in as little as 10-12 years.  It is certainly uncommon (in our experience) to see a roof made from asphalt shingles that has lasted more than 18 years.  Other materials are also not immune from premature need for replacement.  In the case of metal roofs, the primary material is usually long-lasting, but the failure comes from the lack of attention to key details during the installation.

Since homeowners are usually not expecting premature failure, they often fail to carry out routine annual inspections that would reveal the performance (or lack of) the materials installed.  This results in deterioration that is “hidden” in the underlying structure.  The primary “effect” of deterioration we need to be concerned about is the infiltration of water into the interior of the roof.  This contributes to rot, delamination of plies (if covering is plywood), disintegration of the material (if non-exterior OSB), as well as support for mold.

In addition to the materials not lasting as long as the buyers expect, another aspect to reducing the longevity of roofing installations are the typical short-cuts that are taken to keep the price of the roof “affordable”.  It takes time to do a proper roof preparation, and to build in all the little details that ensure a long-lasting roof assembly.  Of course, the preparation and the details are not visible when the final covering goes on, so it’s hard to verify after-the-fact whether there were short-cuts taken.  Given how many roofing contracts are written, there usually is no mention of these preparations or details, and what IS written is related mostly to the visible exterior part.

So whether it is intentional or not, the end result is that our roofs, for the most part, are going to fail much before we expect them to.  Because these failures occur over time, for the most part, they are not perceived as urgent.  These failures undermine the value of our most important investment, our home, and also incur ongoing liabilities in the event that we choose to sell.  They diminish our security and well-being, increase our operating costs and can potentially undermine our health.  It doesn’t have to be this way.

To make informed decisions, it takes knowledge of how things actually work, and experience to project what the consequences will be of the decisions taken.  Protecting yourself by obtaining the facts about your actual situation is the first step.  Identifying the issues, whether actual or potential, and prioritizing them, is the second step.  Finding a company that has the knowledge, experience, and track record to do the right things in correcting the issues identified, is the third step. Choosing the appropriate materials installation process and determining an appropriate budget is the fourth step. Monitoring the performance of the work to ensure that no short-cuts are taken, is the fifth step.  And of course, once the remediation work is completed, following up with annual inspection and doing the required maintenance is the final step of ensuring you get the maximum use of your investment.

We can help with each of the six steps identified above.  This help isn’t “free” (we charge for our consultations), but given the potential consequences of not knowing, it’s an investment in making good decisions.  If you are interested in ensuring that you know the facts, use the contact form to contact us and set up an appointment.

© 2014 Paul Grizenko

#&^!@%$ weather…

I don’t like the new “normal”.  Really.  It might be good for the roofing business, eventually, but it’s getting downright unhealthy.  -20 to -30C temperatures for weeks, followed by +6C this morning.  Wild (90+ kph) wind.  Pretty heavy rain.  Tomorrow’s forecast is for very cold temperatures, allowing all the wet snow to refreeze into blocks of ice.  We “might” escape the freezing rain with its accompanying chaos and power outages, but given Nature’s mood these days, I’m almost expecting a plague of ice-eating locusts.  Better go check my supply of batteries, candles, bottled water and gas for the generator.  Assuming I can hack through the ice to get to it.

No.  I don’t like the weather these days.  On the other hand, it could be Nature’s way of telling us that it’s getting tired of the abuse we seem to heap on it so readily.  If that’s the case, the ride’s going to get wilder.

How assumptions lead us astray

“If others tell us something we make assumptions, and if they don’t tell us something we make assumptions to fulfill our need to know and to replace the need to communicate. Even if we hear something and we don’t understand we make assumptions about what it means and then believe the assumptions. We make all sorts of assumptions because we don’t have the courage to ask questions.”

― Miguel Ruiz,  The Four Agreements: A Practical Guide to Personal Freedom


We can’t live without them.  That’s just a fact of modern life.  We can’t possibly fact-check everything we come across, or hear, or read.  So as a convenient short-cut, we make assumptions that allow us to move onto whatever it is we’re trying to do.  If those assumptions were wrong, then most of the time, it’s usually not a big issue, as we probably didn’t make life-altering decisions based on those wrong assumptions.

Assumptions are the ground upon which we build the structure of our thinking.  Just as most times you don’t probe the ground in front of you before taking a step, you don’t check every bit of information about something before thinking about it, or making a decision, or taking an action.  Most of the time, that’s perfectly fine, because we’re usually in familiar territory and we’ve passed this way and that way many a time without any negative consequences.

When we venture into new areas, we need to be a bit more careful.  Unfamiliar territory “may” be just like what we already know, or it may not.  If it is not, then how will you make sure that it is safe, or that you are making the right decisions?  How do you know that the “rules” in this new place are the same that you are familiar with elsewhere?  The reality is that you don’t know.  And making the wrong assumptions can start having serious consequences.

What does all this have to do with roofing?  Lots, as it turns out.  Roofing is a field of expertise that is alien to most homeowners.  Dealing with contractors, especially if you’re doing it the first time, is also a form of altered reality.  When we get called to figure out a problem, we start by finding out the situation beforehand, what was requested in the contract, what was delivered, and how the result differed from expectations.  As we peel away the various layers, we almost always find that at the base, the problem started with the wrong assumptions being made, which then allowed the wrong decisions, and wrong actions.  We have traced unsatisfactory results to assumptions made by homeowners, by the contractors, and by the workers.  Even inspectors are not immune to this type of fault.

What are the assumptions that lead us astray?  There are, unfortunately, many.  The ones below are probably among the more common, however the list is definitely not exhaustive.

A.    Assumption:  Buying a roof (or renovation) is just like buying a product like a car or a fridge.

Ah.  A very common assumption, which could be true IF all homes were constructed in the same way, had the same history, had the same environment,  were used in the same way, and were installed to the same standard.  However, the roof is not ON the house, but is PART OF the house, and interacts with various elements in the structure.  Since every home is somewhat different, the way the roof needs to be built and integrated with the rest of the structure is different for each situation.  When you add to this the differences in the performance expectations that the homeowners may have, then it should be obvious that doing a re-roofing project is much more involved than just replacing the roof covering.

Another common fallacy is that the specs are sufficient to make a decision.  When you compare products, you usually get the specs and compare them – what’s the performance, fuel efficiency of energy efficiency, operating costs, capacity, etc.  However, the specs for a reroofing project are usually much more poorly defined.  If you are relying on contractors to tell you what needs to be done (as part of the “free estimate”), you actually have no clue about what they will actually deliver, and if they have determined what needs to be done in a thorough and correct manner.  If you don’t know which questions to ask, then you also do not know if your needs expectations (whether expressed or not) will be met.

It’s should therefore not be a huge surprise that the estimates can vary all over the place – and the assumptions made by the contractors are also not explicitly identified, so the “real” scope of work that will be done is very variable.  In fact, when comparing estimates, we often find that the price for doing the visible part of the work (putting on the roof covering, for instance), is very close, but there is wide variation in the preparation and detail work.

If you DO want to make the comparison of quotes consistent, then YOU have to give the bidders a comprehensive spec which identifies the work to be done in detail, and references the products and quantities that are to be used.  This spec is known as a “Request for Quotations” document, and identifies exactly what your expectations are.  This is common for commercial work, but unusual for residential installations.  And yet, without this kind of information, how do you know what you are buying?

B.    Assumption:  The marketing information is accurate.

We all love poring through the nice shiny advertising brochures, looking at the attractive models and locations, and imagining ourselves having some of that good fortune.  Of course, there’s a little game being played here – we’re being invited to project ourselves enjoying the benefits of the services or products.  To help us in this fantasy, to allow us to rationalize it to ourselves, the advertisers list the various attributes that should allow us to agree that this product or service will deliver.  This is known as marketing copy.  It is, if done properly, very seductive and persuasive.

However, we all know that in real life, we don’t usually get only the benefit.  There are trade-offs, side-effects, compromises, and other consequences that don’t get mentioned in advertising copy.  Where do we find out about those?  That’s where the hard work of research has to come in.  Some of the ways to verify advertising claims include:

  • Reading the warranty or guarantee information, and most importantly, the exclusions,
  • If test results are being quoted, then looking up the tests done, and understanding under which conditions the test results are applicable,
  • Checking reviews by (hopefully) independent sources,
  • Seeing actual performance of products over time.

In other words, we need to find out under which conditions the marketing claims have the possibility of being realistic.  Otherwise, we’re just buying into a really nice fairy-tale, and expecting the “living-happily-ever-after” to happen to us.

C.     Assumption:  The warranty is there to protect me.

Or course it is.  That’s why it’s written by lawyers hired by the company supplying the product or service.  That’s why it’s written in easy-to-read fine print, and in easy-to-understand legal language.  That why there are clauses saying that the warranty is in effect only if the product is used as intended by the manufacturer.  And of course you will ONLY use it in the way it was intended, and ONLY under the conditions under which it is warranted.

Warranties, when referenced by advertising, are in fact marketing documents.  They also are a legal limitation of liability by the company, intended to keep their obligation to the consumer/user of the product at a minimum level.  They can’t totally escape all obligations – our various laws prevent for the most part that kind of escape, but they can limit the consequences to themselves.

There is a class of warranties that are wonderful to read in the scope of benefit they promise.  However, keep in mind that the warranty is in effect only as long as the specific entity that issues the warranty exists.  Therefore the most generous warranties are written with the expectation by the issuer that they won’t be in business when the warranty claims start pouring in.  Those companies that DO stand behind their warranties are usually very careful to limit their liability to ensure that they can deliver on the promises made.

However, stuff sometimes happens even to the best companies.  When those companies disappear, or get bought out, the warranty promises evaporate.  It turns out that the best warranty is the knowledge that the product or service is well built or delivered, and that there is no need for a warranty claim in the future.  When it comes to roofing, the best warranty is a contractor who knows what he or she is doing.  Which brings us to the next assumption.

D.    Assumption:  The contractor knows what he or she is doing.

This is a natural and normal assumption.  After all, the company wouldn’t be in business if they didn’t know their trade, right?  That’s true for the good contractors.  However, the fact that they are in business doesn’t mean they are good, just as the fact that a person is breathing and alive doesn’t make them a “good” person.

So how do you know if a contractor knows what he or she is doing?  There are ways to find out.  I’ve covered much of this in the article “How to choose a Contractor (in Quebec)”.  However, it is also important to know that the workers or subcontractors also know their trade, and that is where most people fail to dig deeply enough.

Another aspect of this assumption, is that the contractor also has a degree in mind-reading, and knows what your expectations are even if these are not voiced or written down.  If the expectations ARE fully expressed, it is an assumption that he or she will understand exactly the same thing you are meaning (if you doubt that, then you were never married or had a close partner).

Therefore, when the work is under way, it is very important to check in periodically with the contractor, or the crew chief, or the foreman to verify that what is being done DOES conform to your expectations.  If they know what they are doing, they’ll have no problem explaining what, how, and why they are doing something.  If they can’t or won’t explain, then that’s a big red flag.

E.     Assumption:  The contract doesn’t have to cover every detail, because it’s obvious what has to be done.

As was noted in the previous section, what is obvious to you may not be obvious to the contractor, and vise versa.  A good contract should clearly identify all the work to be done, and just as importantly, put limits on the work being done.  This is to avoid “mission creep” when the original project morphs into something else.  This is a particular problem with longer projects, and it can be both very expensive, and very frustrating to all concerned.

We notice that the preparation and repair work often gets a minimum of discussion, if at all, and yet this is where the biggest discrepancies often are found, between what is done, and what should have been done.  On some projects, the prep work can be equal to or even more than the cost of the “main” work.  Since good preparation is the foundation on which the rest of the project is built, skimping on it almost always leads to unsatisfactory results.  And yet, it almost never gets properly discussed and described in the contract.

F.     Assumption:  The building structure is fine.  We checked one part and it should be the same everywhere.

If the original inspection was done in a cursory manner, then this assumption can wreak havoc on schedules costs, and effectiveness of the result.  As noted earlier, a re-roofing project is the blending of the old with the new.  If the insulation is good in one area, but poor in another, you can’t use the same approach in both.  How this gets resolved depends partly on the type of contractor you have.  The good ones will bring the “surprise” discovery to your attention, and propose one or more ways to change the scope of work to accommodate this discovery (at additional cost, of course).  The unscrupulous ones may either use this as an excuse to really jack up the price (especially if they won with a very low bid), or they can pretend that there was no surprise, and work as if it wasn’t there.  In the latter case, you’ll have the surprise down the road, when things aren’t working as they should.

This comes back to the point, that the best way to prevent this kind of surprise is to do a thorough inspection before starting the project.  If there are areas that are hidden, they should be opened up and explored, especially if those areas have been linked to problems.


It has been said, that wisdom to make good choices comes from experience, and experience comes from bad choices.  The smart person learns from the bad choices of others.  So, be smart, hire us to help you define what needs to be done, and put together a plan to make it happen.

© 2014 Paul Grizenko

Roof Inspections

A fundamental activity in assessing the status of a roof is a thorough inspection.  Unfortunately, too often, it is not done, or done poorly by the roofing salesman, or the roofing representative or an inspector.  This is partly due to lack of knowledge/training, and partly due to attitude.  So, what should you expect to see or learn from a proper roof inspection?

The first thing to consider is that the roof is part of the house’s external envelope, and as such interacts with the rest of the house.  The house construction depends partly on the time when the house was built, and the building codes in effect at the time, and partly on the design/construction choices that were made.  Many older homes have also had renovations and “improvements” done to them, not always by qualified people, and not always taking into account the way these changes affect the rest of the house.

Other factors that affect the way the overall system functions include the living habits and lifestyles, the location of the house relative to its environment, the current prevailing climate, and the degree and type of vegetation around the property. 

Inspections therefore serve to reveal the “ground truth” of a home’s construction, quantify to a degree how the various components interact, and reveal the deficiencies and weaknesses.  With this information in hand, it is then possible to determine which changes are necessary, and to prioritize them if they cannot all be done at the same time.

Why isn’t this done all the time?  Homeowners usually don’t do this because they lack the knowledge, experience and (sometimes) the ability to conduct an inspection.  Home inspectors (particularly the ones who give a checklist inspection at very little cost) usually are generalists, and are focused on the current state of the home, and not necessarily on the cause-and-effect.  Salesmen often don’t do this because it can be dirty work, they don’t have the knowledge about the things that can go wrong, and in any case, their job is to make a sale of product or service, not to play consultant. 

What should you expect from a good inspection?  While the answer depends on the house, the objectives of the inspection, and the intended use of the inspection information, the list below covers some of the aspects:

  • Assessment of the roof covering, penetrations, seals and flashings,
  • Assessment of the decking/sheathing condition and structure,
  • Assessment of the insulation type, distribution, effectiveness and condition,
  • Assessment of the ventilation function, quantity, distribution and effectiveness
  • Determination of the way the snow behaves on the roof in winter
  • Determination of the way the water run-off works,
  • Assessment of the effectiveness of the vapour barriers
  • Determination of issues of condensation, inappropriate venting, and insufficient sealing against air movement

As part of the above list of areas to cover during the inspection, it is also necessary to understand what one is seeing.  When is 12″ of insulation more than adequate, and when is it grossly insufficient?  Why is having lots of large Maximum vents not always the perfect solution to ventilation issues?  When is a roof with curling shingles in better shape than one with the shingles all lying flat?  When is an ice-dam a reason to worry, and when can you safely ignore it?  What is the significance of rusty-looking nails protruding through the sheathing?  It is relatively common to find overlapping deficiencies that amplify the effects.

Sometimes, it is not possible to access all parts of the roof system, and it becomes necessary to do “exploratory surgery” to establish the facts of the physical reality.  This is often the case when a problematic portion of the roof is hidden due to the way it was constructed, or because it was sealed off to prevent a careful inspection.  The latter is a red flag.  I remember one particular situation when I was hired by a young couple to check the state of the roof of their newly-purchased home in an older part of town.  The renovations done by the previous owner did not allow access to the attic or any cold spaces.  When we succeeded in gaining access, we discovered the insulation completely covered in black mold.  Upon getting our report, the owners did some further investigation (removal of portion of a gyproc wall in their newborn daughter’s bedroom) and found the entire wall space covered with mold.  It turned out that the history of the building was not disclosed to the buyers and the seller was “flipping” the property after acquiring it for almost nothing.  The new owners had to move out and pursue redress through the courts.

Other types of issues we’ve seen during inspections, is the problems that putting in additions or extensions without fully understanding the operation of the “system” can cause.  Typically, when a cold space is converted into a heated, four-season space, there is not enough thought put into how the insulation, ventilation and vapour barriers will interact.  This results in appearance of condensation in places it was never present before, in the transfer of heat to the roof that was not a problem in the original structure, and in various other symptoms.  When the new owners are trying to rectify the surprising deficiencies, they often find that the money spent on the repairs is wasted, as the root causes of the deficiencies were not addressed.

Most people buying an older home do not have an unlimited budget to rebuild it to meet all the current requirements.  Therefore, having a good inspection is important to allow effective evaluation of which issues are critical, which are important, and which can be lived with.  From this assessment, it is then possible to develop a phased approach to addressing the issues in a systematic manner.

Why can’t you get the inspection done as part of a “free estimate” advertised by many companies?  You might get lucky and get a knowledgeable roofer (not a salesman!) who will take the time to understand your situation.  Chances are however more likely that you will get a “consultant” or “representative” who is there to sell you a roof.  Their first, second, and third priority is to make the sale, and to use whatever justification they can find to win your trust and persuade you to agree.  Since most companies have a “primary advantage” of some kind over the competition, that becomes their solution to any issue you may have (when all you have is a hammer, then everything looks like a nail).  Their solution may address part of the problem, but not necessarily all the aspects.

Doing a good inspection is necessary to establish the cause-and-effect, the weaknesses, scope of work, the priorities, and the sequence in which the work should be done.  It usually requires much more than a 15 minute walk around of the property.  Everything that the inspector sees or notes, should be documented with photographs, and quantified by measurement. For instance, in a recent consulting engagement, the homeowners were told by an inspector that the insulation was “good”.  After my inspections, we were able to determine that:

  • The insulation varied from 8-10 inches of cellulose fill over old fiberglass insulation in one part of the roof (the client had contracted for 12″ of fill over the vapour barrier),
  • The insulation was blown into the soffit cavity (thereby obstructing the air intake from the soffits)
  • The insulation in another part of the roof was equivalent to only 6″ of fiberglass (giving at best about R18, instead of the desired R40), and the insulation in that part was not packed effectively, severely reducing the effectiveness of the insulation that was there.
  • The quantity and quality of insulation in a newish extension was unknown as that entire area was not accessible, but suspect from the quantity of ice damming occurring.

After the inspection, the inspector should be able to show the images of deficiencies found, and explain what should be the desired state, and how much of a discrepancy is shown between that state and the actual state.

If you’re in the greater Montreal area and want to have us do an inspection for you, please use the contact page to send us a request for such a consultation.  If you’re further afield, but want to have a detailed check list, use the contact form to give us your contact coordinates.  I’ll then call you to determine if we can help you, and if so, which form this help can take.

I’d love to hear of your experiences with inspections.  Use the comment link to make the comments on this page. 

(c) 2014 Paul Grizenko