You’re mad -your roofer didn’t do the job

You were happy to have the roof done a few years ago and you were delighted when the roofer told you he saved you money.  Except that now your gyproc is showing signs of water damage, and the last roof lasted 15 years without any leaks in that location.  What should you do?

The quick answer is:

  1. Diagnose the problem
  2. Identify the probable cause
  3. Assemble your evidence
  4. Notify the party responsible in writing
  5. Give adequate time for the party responsible to respond and correct
  6. If no acceptable solution is reached, escalate

The long form of the answer follows below.  (Disclaimer:  I am not giving legal advice in this post.  The following discussion is only one of the ways such issues can be resolved, and there may be other mechanisms available to you that are not covered in this post).

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Condensation plays the same role in “modern” roofing practice as “bad spirits” did in medieval times.  If something went wrong, you blamed the bad spirits.  Nowadays, if a roofing system is not working, it’s due to “condensation”.  So let’s get into it and understand what condensation is, when can it appear in a roof system, and what corrective action you can and should take if condensation is really the cause of an apparent leakage.

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Metal roofing – the green solution for your house.  Or is it?

Compared to (most) asphalt shingle roofs, (most) metal roofs last much longer and perform much better, as long as they are properly installed.

Metal roofs are considered to be more ecological than asphalt roofs, as their longevity usually means that the metal roof is the last roof the home will need.  This longevity also means that fewer manufacturing resources are needed to produce this roof, compared to the resources needed for asphalt shingles over the life of the house.

However, this longevity of product may not be enjoyed by the homeowners, if the installation was not properly done.  Even if the installers followed the manufacturer’s recommended installation practice, a roof may fail prematurely IF the roof covering was not properly integrated with the rest of the house structure.

So let’s look at what “should” be taken into account when considering a roofing solution.

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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

Roof Leaks – causes and fixes

The most common symptom of a roof leak is bubbling paint or stains in the ceiling gyproc.  Sometimes the leak appears at the ceiling/wall joint, sometimes it is becomes visible at the seam tape between the gyproc panels.  At times, it is not subtle at all, with a large amount of water running down the walls or dripping onto your floors.  Other times, the leaks are very subtle, and don’t show up as interior damage at all, but do let water into the attic or the cold spaces.

Leakage from ice dam appears in several places.

Leakage from ice dam appears in several places.

The first thing to figure out is whether this problem is new, or whether it has happened before.  If you’ve lived in the same home for more than a few years, and you’ve never seen it before, then chances are excellent that something changed recently, and therefore contributed to the leak.  If you’ve been in the house for under two years, then it is possible that the former owner did not disclose the history of prior leaks, and therefore the leak you see for the first time, may in fact be a long-standing issue that was hidden by new gyproc and/or paint.

There are many possible causes of roof leaks.  For “new” leaks, common causes are:

  • ice dams
  • gutter/eavestrough icing
  • wind damage to roof cover
  • failure of caulking or sealant
  • physical damage to the roof surface by falling objects or ice
  • failure of a waterproofing layer
  • installation of a bathroom, kitchen or drier outlet into the attic
  • Installation of pot lights or recessed ceiling lights

Other leaks, especially if they have been present for a while, are often caused by:

  • poor installation of waterproofing layers
  • poor design and/or installation of flashings
  • use of inappropriate products to cover or waterproof the roof
  • incorrect amount of ventilation and/or insulation for the roof design
  • poor detailing of roof penetrations (air vents, plumbing vents, electrical poles, etc.)
  • poor design of roof/wall flashings
  • leaks in caulking at window and skylights
  • poor placement of vents and other roof openings relative to wind direction
  • condensation

If there were short-cuts taken during the installation of the last roof, then these usually contribute to making the original problem worse.  For example, some roofers advocate leaving the old roof on because it gives “extra protection”.  When a leak DOES happen, then the layers of old roofing provide an additional path for water to run in different directions.  Other times, they “save you the cost of new flashings” and reinstall the old flashing – this works until the water finds the holes.  Still other times, the various materials were not installed according to manufacturer directions, and therefore did not provide the appropriate waterproof seals that were expected (this is a common installation failure for waterproofing membranes).

Old shingles left on, contributed to channeling leak to different location

Old shingles left on, contributed to channeling leak to different location

It is common to find that there is not a single point of failure, but a series of weaknesses that contributed to allowing the leak.  For example:  The primary cause is an ice dam, which allowed water to find a poorly-caulked joint, when then ran onto waterproofing membrane until it found an open seam, and then into the roof.  Once it entered the roof, it ran on the underside of a beam until it came across a supporting strut, at which point the water dripped down onto the insulation, and through the insulation onto the vapour barrier.  Then it pooled on the vapour barrier until there was enough to direct it to a gap in the vapour barrier, and onto the gyproc.  It finally showed up as bubbling of paint on a gyproc seam.  Where it came in can be quite far from where the leak actually occured.  So when looking at a source of the leak, it is necessary to play detective, and follow the water trail.  Sometimes it is quite easy.  Usually, it is not.

In the above example, the solution (short-term), would be to remove the ice dam, and to dry out the accumulated water on top of the vapour barrier.  However, the long-term solution is to add enough insulation to prevent the melting of snow in the first place, then have enough ventilation to remove any residual heat leaking past the ventilation and any moisture that may be entering the attic.  When the roof gets redone, the membrane needs to be properly applied (right product, right installation method, right location), following by the appropriate flashings, and finally counterflashings and caulking.

In some cases, we’ve seen roof covering deteriorate to the point that water is freely running on the underlayment, and every gap in the underlayment allows entry of water through the nail-holes and other breaks in the underlayment surface.  If the decking is made from OSB (Oriented Strand Board) of the Exposure 1 grade, then there is a high probability that the decking will be damaged extensively as well, and will need to be replaced.  If the leakage has occured over a period of time longer than one year, then there are also mold issues to consider.

In short, a leak is telling you that there are potentially major issues to be dealt with.  Before throwing money at the problem, take the time to figure out what’s actually going on, and what the priorities should be in terms of fixing the problems in both short and medium terms.  If you contacted your last roofer and he claims that there’s no problem (that he’s responsible for fixing), maybe it’s time for a second opinion.  After this, you will have a better idea of what the problems may be, and what would be a reasonable approach to getting them resolved.

(c) 2013 Paul Grizenko

To get the right answer, you need to ask the right question.

If you are a parent, you know that already.  If you’re not yet a parent, well… you’ll find out.

The same applies when you’re interviewing someone for a job.  You check the resumé, the credentials, the references, you ask the questions about work experience, ability to work alone or in a group, etc.  Chances are, you know what the applicant needs to know and you can usually tell when someone is b/s-ing you.  However, a good interviewing technique is to ask the right questions.  And when you’re doing the interview for a position in your field, you know enough to know what the right questions are.

Now, you’re about to look for someone to put a new roof on your home, or perhaps to carry out the repairs.  You’re also going to be conducting interviews, but now, the chances are excellent that roofing is not your area of expertise.  In fact, the problem usually is that you don’t know what you don’t know.  So how will you be able to ask the right questions?

There are usually two ways of approaching this lack of knowledge.  One way is to educate yourself, by talking to neighbours and friends, by reading up on the subject, and by poking around on your roof and in your attic to try to understand what is going on there.  This approach will, at a minimum, give you a basic vocabulary, and an idea of how things work.  You still don’t have a lot of experience to guide your ideas of what is truly important and what is not, but you’re building up a base of knowledge.

The other way, is to rely on the good-will and the honesty of the contractors you will invite to quote on your project.  If you are lucky, one or maybe even all, will conduct an inspection, and give you a written quote.  If you are really, really lucky, you may be dealing with an ethical and knowledgeable contractor with many years of experience.  Chances are, you’ll be “pitched” by a sales rep, who will have some nice brochures showing styles and colours, and who will check off an official looking form that lists the type of work to be done on your roof.  Very nice.  But now, it’s time to start asking the right questions.  Such as:

  • What specifically is wrong with my roof, and what is working well?
  • What are the causes of the things that are wrong?
  • What is your evidence that you have got the right causes?
  • What are the weaknesses of the roof?  Which are potential, and which are causing issues at the present time?
  • How will your proposed scope of work correct the causes of the problems we’re seeing?
  • Which materials will you be using, and what is your evidence that these are the proper materials in our situation?  What kind of warranties are being supplied with the materials?  Are there any conditions on our roof that may void these warranties?
  • What is your experience in fixing the type of issues we have on our roof?  Can we have a list of references of prior work that had the same problem?
  • Who is going to do the work?  What kind of training and experience do they have?  How long have they been working with your company?  What licenses and permits do they hold?
  • What kind of warranty will you be supplying on the installation (labour)?  What are the exclusions, limitations, and clauses that may limit the responsibility you have for the installation?
  • What protocol do you follow if you find things after the start of the work, that were not covered in the contract?  How will you assure me that this “extra” work is actually needed, and is not an attempt to increase the profits by doing unnecessary work?

What happens when you don’t ask the right questions?  Well, you get fed a story, and it may be a very attractive story.  But if the story doesn’t address your specific situation, then you’re getting a performance.  Performances can be very entertaining, but at the end of the exercise, you will have paid out thousands of dollars for… what exactly?  You may convince yourself that you have gotten a deal, and that the end result looks pretty good.  But if you haven’t asked the right questions, you may end up with a very expensive band-aid over a problem that was not fixed and will come back again.

Asking the right questions is important.  If you don’t know the vocabulary, we can offer you our expertise.  It may be to do a full and proper inspection to determine the exact state of your roofing system.  It may be to develop a plan to address specific issues in a comprehensive way.  It may be to review the quotations submitted and read between the lines to see what will actually be done.  It’s always a lot cheaper to get it done right the first time, than to try and fix something after the fact.

And it starts with knowing which questions are the right questions to ask.

(c) 2013 Paul Grizenko

Climate change and your roof.

Whether we believe that human activity has caused or contributed to climate change, the simple reality is that the weather is not the same as it was before.  The warming of the atmosphere promotes more evaporation, and this brings an increase in the energy contained in the atmosphere.  More energy means more variation, with larger movements of air, stronger atmospheric pressure variation (both highs and lows), heavier precipitation, and much more wind.

 In practical terms, this means that winds of 80+ km/hr will be more common, and we should expect at least several times a year when our roofs will see winds of 120+ km/hr.  In terms of precipitation, heavy downpours of 30-40mm per hour may be more common, and need to be planned for.  We can also expect heavier snowfalls, and rapid changes in temperature.

 So…  how is your roof set up to handle these weather conditions?  Probably not all that well.  If your roof was put together to meet the minimums in the building code, which was based on data accumulated prior to the 1980’s, then your roof is built to deal with conditions that have dramatically changed since that time.

 The typical roof failure we’ve seen in recent years include:

  • Shingles blow-off
  • Water infiltration due to wind-driven rain
  • Damage to fascia, soffits and siding
  • Leakage due to rapid melting of snow accumulating on the roof, then refreezing,
  • Leakage due to volume of rain overwhelming the gutters, and backing up the eaves, valleys and end-walls,
  • Excessive wear on shingles from water falling from a higher level
  • Excessive drying-out due to prolonged heat and sun exposure
  • Caulking failures around chimneys, skylights, vents and other roof features
  • Excessive snowfalls with up to 24″ or more of snow accumulation requiring snow clearing to reduce the weight on the roof.

 It would be a good idea to verify that your roof system can cope with the new conditions, and if weaknesses are found, to determine the best way to “fortify” your castle.  If you wait for a news-worthy weather event to damage your roof, you may be looking at a very expensive repair bill, not to mention inconvenience and even some personal danger.

 If you haven’t considered it before, maybe it is time to look at some of the newer products and installation methods that have a much better ability to cope with the temper tantrums that Nature seems to throw more often.

 At the very least, you may want to look at the incorporating layers of protection that should allow your roof to withstand the more extreme events.  Each roof behaves somewhat differently, so an inspection is usually needed to establish the potential weaknesses, and the appropriate counter-measures.

(c) 2013 Paul Grizenko

Waterproofing membranes for roofs – Miracle product or junk?

The last time you had your roof done, you wanted to be sure that the leaks you had before would never happen again, and you made sure that your roofer installed waterproofing membrane to protect your roof.  Now it’s winter, and you’re having some leakage issues.  WHY?

Let’s start by examining what are waterproofing membranes, and how are they should be used.

There are a number of products that are marketed as waterproofing membranes for sloped roofs.  There are different grades, performances and price-points.  For the membranes to work properly, they need to be properly installed, under the right conditions, at the right place(s) and for the right purpose.  As is true for all building materials, they have both strengths and weaknesses, which must be taken into account by the installers.  From their method of application, they are also known as “peel-and-stick” membranes.

In general the membranes work by bonding (melting into) the wood decking, and thereby providing a waterproofing bitumen layer which keeps the water out.  The membranes bond well to each other, and to wood (provided it is dry and warm enough).  When pierced by a fastener such as a nail, the material acts as a gasket around the nail and resists water penetration.  Therefore, if the membrane is applied to the right place, in the correct way, at the right temperature, and to the right materials, it works.

Membranes, however, sometimes fail.  It is useful to know the different ways failure can happen.

  • The membrane was not installed over dry, solid wood.  This meant that the membrane could not bond to the wood, and thereby establish a waterproofing layer.
  • The membrane was installed over non-wood materials.  This is a common failure, found when the installer did not properly prime the non-wood surface to ensure both adhesion of the membrane and the creation of a waterproof seal.
  • The membrane was not overlapped sufficiently.  Each membrane has a minimum overlap requirement, and the installers MUST ensure that the bond between successive layers is active.  This kind of failure also happens if the membrane was laid vertically when it should have been laid horizontally.  The vertical joints are more susceptible to leakage.
  • The membrane was cut flush with the edge of the roof.  This is a common installation failure, which allows the water that may be on the surface of the membrane to enter the decking at the edge of the roof.  Proper installation practice is to run the membrane past the roof edges by at least 1-2 inches to ensure the water stays outside the roof system.
  • The membrane was installed over damaged wood or on a joint.  Fasteners piercing the membrane at those points will not have the solid wood support that ensures the dimensional stability of the puncture point, and therefore, water will enter the roof system through the nail holes in those locations.
  • The membrane was installed over a non-ventilated space.  This may become a very serious issue if the space is NOT sealed, and may contain moisture or water vapour.  This is known as “trapping” the moisture, and will lead to both wood rot and mold (potentially toxic) in the spaces.
  • The membrane cracked or torn, letting in water.  This can happen if the membrane was left exposed to the sun for longer than the manufacturer recommended, or if there was movement in the structure that put tension on the membrane.  This can also happen more easily with cheaper membranes.
  • The wrong kind of primer was used, leading the materials to “melt” the membrane, instead of providing a suitable attachment point.

There are, of course, many more ways the membranes can fail to work, but as can be seen above, if a membrane doesn’t work, it’s almost always because the installer failed to do the installation properly.  Proper application of the membrane takes time, and ensuring that the overlaps are all properly sealed, and that the junctions to various roof penetrations are properly primed and joined, is detail work that cannot be rushed.  As well, as in painting, if the proper preparation is not done, then the adhesion of the waterproofing layer is going to be compromised.

In our experience, the failure of the waterproofing layers is a very common reason for replacing a roof prematurely.  Unfortunately, once the roof covering is on, it’s impossible to verify whether this critical element was properly installed.  In practice, if the cause of a roofing failure is suspected to be linked to the membrane, it is often necessary to disassemble the roof system and to do an “autopsy” to determine the cause of the failure.

So, how do you ensure that the waterproofing step is properly done?  There are a number of steps that help you get to the desired result.

  • Check the products that will be used.  Get the brand names, the product names, and the installation specifications.  Read carefully the parts about what NOT to do.  Make sure that the manufacturer’s suggested use covers what you want to use it for.
  • If you’re having someone else install the products (your roofer, for instance), ask them to explain where they would use the products, what kind of preparation they will do, what kind of verification or quality control they will do to ensure the materials will work as intended.  Ideally, they should be able to show photographs of prior installations where they did the membrane application.  Probably more important, is asking them under which circumstances the products did NOT work, and what they would do if those circumstances were found on your roof.
  • Once the installation starts, you need to check how the material is being installed.  How well was the roof preparation carried out?  Are the non-wood surfaces being primed with the appropriate primer?  How are the overlaps sealed?  Is the edge of the roof being overlapped?  Imagine water running on the surface.  Where will it go?  Is there a chance for obstruction?  Is there any apparent damage to the material during the course of installation?
  • Once the installation is complete, but before the covering or flashing is put over the membrane, the surface needs to be verified as to its adhesion, overlap, and coverage.  It is a good idea to request (in the contract) that photographs be taken of all roof penetrations, roof joins (such as valleys, endwalls, sidewalls), and roof terminations (rake or gable end, eave, hip, ridge) to show how those details were executed.  Alternatively, hiring a third party to conduct an inspection at this stage is another way to ensure that this critical step in the process is properly done.
  • Occasionally, especially with complicated roof lines and assemblies, it is appropriate to conduct a water test to ensure that there are no weak spots in the water-proofing coverage.
  • If membrane will be installed over the entire roof, it is really, really important to ensure that EITHER the roof system below the membrane is sealed and impermeable to water vapour, OR that it is well vented, so that any moisture trapped under the membrane can escape.  If a roofer or contractor agrees to install the membrane over the entire roof without make sure that either condition exists to a satisfactory level, they are being at best ignorant, and at worst, willfully negligent.

Of course, the membrane protection is only part of a well-constructed roof system.  Good installers will build in several layers of over-lapping protection to ensure that there is no single point of weakness that can undermine the efforts put into building the roof system.  If you’re not sure what needs to be done with your roof, give us a call.  We can give you an intelligent analysis of what issues are important in your situation, and what you need to do to make sure your system works.

(c) 2013 Paul Grizenko


Below are two membranes that we use routinely, and that have been, in our experience, proven to work well, provided they are used correctly.

Grace Ice and Water Shield Membrane:

Interwrap – Titanium PSU membrane:

Further information:

If you are interested in knowing more, use the contact form (under the Contact Us menu selection), or give us a call at 514-636-2300.

When is a roof leak not a leak?


We were asked to investigate this leak.  It turned out to be due to condensation.  The pot lights were added much after the construction of the house, and the installer did not use an air-tight insulated box for each light.  As a consequence, warm and humid interior air entered through the pot-light enclosure  into the ceiling cavity, and with minimal insulation left (because it was mostly removed to make room for the pot lights), there was a LOT of condensation.

The do-it-yourself remodeller also made similar mistakes elsewhere in the house, piercing the vapour barriers, and not allowing any air circulation above the insulation.  As a result, the interior air infiltrated the cold spaces and almost “rained” condensation into the interior.

In the section, there is a link to a very good article in Fine Home-building Magazine which discusses ventilation issues and has some nice diagrams showing show how the ventilation should work.

We also have had reported leaks in bathroom fans, which turned out to be condensation, and other “leaks” which turned out to be condensation from poorly insulated air ducts conducting cold air (in summer, obviously).  So when you spot a “leak”, it may not be what you think it is.  Time to do a little sleuthing.

(c) 2013 Paul Grizenko