Comp shingles over wood shingles

[Russel Ray]

Whaddaya think about that California Valley? Isn't that the most beautiful thing you've ever seen?

[Marcel R. Cyr]

Sorry RR; I think I will stick to the cut valleys of Maine. ha. ha.
It took me awhile to accept the cut valleys, but that is only because nobody left that knows how to weave them anymore and takes to much time.

Marcel

[Dan Bowers, CMI]

Marcel or Others -

Sorry guys, you're thinking new roof - its not. A re-roof by putting composition over wood shingles is totally acceptable and usually done when a wood shingle roof goes bad the 1st time. We use more wood roofs around here than even many places in Colorado or the North woods.

You're right it would be my preferred choice to tear it off and start again, BUT unless your local code requires it, its not a code requirement. I don't know a code inspector, insurance adjustor, appraiser or home inspector that would say it was required to tear off and do from scratch as its been described here.

[Jeffrey R. Pope]

I really thought this was a "no-brainer" and haven't responded because I thought it would die a quick death.

Most codes allow for layering of materials. That does not mean it's a good practice. In fact, it is considered by most professionals to be poor practice.

I know of no manufacturer (of comp-shingles) that will honor their material warranty after comp has been laid over wood-shake or wood-shingle. I can think of several reasons why. . .

[Dan Bowers, CMI]

I also thought this was a "no-brainer" and have been really amazed at the responses on this board. I'm outside of Kansas City. For the most part we use the IRC 2003; some use an earlier version; a few are on UBC; one is on IRC 2006.

You can go over wood shingles with a composition shingle 1 time per IRC 2003.

Last year, I had heard that you could only have 1 layer by IRC 2006 codes and that it would void a manufacturers warranty. So I wrote up 2 that way. I got jumped on bigtime by city code guys, roofer and insurance company - not to mention agents, seller and even buyer for running off mouth when not true in our area and creating a huge problem that did not exist.

So when I saw this post I was curious again, and started calling roofers, insurance adjusters, roofing suppliers, code departments, etc. I was once again assured that may be somebodies rule somewhere else - but not here.

So - for any new guys online, check your own area. When one of us says its not allowed and will void a warranty OR says its 100% OK and you write it up as gospel - you may or may not be demonstrating pure and total ignorance.

[Jeffrey R. Pope]

There are several municipalities in the Los Angeles area that have adopted ordinances requiring complete removal of all wood-shake/shingle roofing material, regardless of when it was installed. In other words, they have "outlawed" wood-shake/shingle roofs.

The city of Burbank (for instance) requires that all home owners submit a "certification" by 2012, to the Building Department, showing compliance of the "wood free" ordinance.

Obviously this has nothing to do with layering, but the point is that local ordinances will vary throughout the country.

In any event, I always report on layered material if to say nothing other than "it's not a good idea."

[Keith Swift, PhD.]

I agree with Jeff. Layering over a wood roof on what is also called spaced-sheathing has not been permitted in the City of Los Angeles since August 1989. (The City of Burbank is an exception). Regardless, it's a bad idea because the fasteners have a tendency to split the old dried shingles/shakes and leave the new shingles susceptible to wind-damage. I always describe what I see, state that "layering" is a common practice but not one that is sensibly recommended, and then recommend a second opinion. This may just the opinion of a certified "deal-killer".

[Larry D. Kage]

Originally Posted by kswift

I agree with Jeff. Layering over a wood roof on what is also called spaced-sheathing has not been permitted in the City of Los Angeles since August 1989. (The City of Burbank is an exception). Regardless, it's a bad idea because the fasteners have a tendency to split the old dried shingles/shakes and leave the new shingles susceptible to wind-damage. I always describe what I see, state that "layering" is a common practice but not one that is sensibly recommended, and then recommend a second opinion. This may just the opinion of a certified "deal-killer".

Agreed...

[Marcel R. Cyr]

I also agree with that assessment and certainly would never condone adding composition shingles on top of one or two layers of shingles or shakes.

Code or not.

I will note what I see and recommend proper install from the building standard of this area. What they do after that is their choice.

Marcel

[Dan Bowers, CMI]

Like I said - that may be the case somewhere, but not everywhere. Been done that way here for 20 years or so. Its always amazing however to hear how other areas do these things. Like outlawing wood roofs in Burbank.

Cool.

[Russel Ray]

Originally Posted by dbowers

Like outlawing wood roofs in Burbank.

And, after the October 2003 fires here, all of San Diego County.

[Larry D. Kage]

Originally Posted by dbowers

Been done that way here for 20 years or so.

We've all heard that before...

[bchew]

I simply remind my client that there is a big difference between doing the minimum required by law (code) and doing the job so it will perform well and last a long time. Then I say that by choosing to install the comp shingles over the wood shingles, a previous owner saved some cost on the comp shingle installation and by doing so it shortened the life of the comp shingles, meaning they will need to be replaced sooner than if the wood shingles had been removed before they were installed.

At this point I discuss my observations of the current condition of the comp shingles. Then I say that when it is time to replace the comp shingles, everything will need to be torn off and new roof decking will need to be installed before the new roof covering can be applied.

My recommendation to my client is to have a qualified roofer come out and give two estimates: one for a complete tear off of both layers and installation of new decking and comp shingles (what it would actually cost my client for a new roof at this point in time), and one for a tear off and install assuming this home had solid decking in place and one layer of comp shingles. Then I explain that the difference in cost between those two estimates is what the current owner is transferring to my client along with the title to the home. It is up to my client and his agent to decide if that cost is adequately reflected in the current agreed upon purchase price. Rest assured, the seller and the seller's agent are not going to be happy with this advice but my client is ecstatic!

[Dan Bowers, CMI]

As most of you probably already know, the Rep for Midwest Region of the Cedar Shake & Shingle Bureau lived in KC for 7 years. I've taught classes with him in KC, St. Louis, Indy, etc. He said not a problem from their perspective.

Realtors, sellers, contractors, etc are often looking for a way to cast doubts on the accuracy of a home inspectors report OR upon his/her credibility. If they can find something that you're calling as wrong - when the installer, supplier, codes say it's acceptable - it can make you sound like an idjit depending on how you report it.

If they show the client you're out in left field over one major thing, they will then often use that to cast dispute over your whole report (and you).

Good hunting!