Comp shingles over wood shingles

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.”

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…

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 :slight_smile:

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.

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

We’ve all heard that before…:stuck_out_tongue:

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!

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!