We Found Two Roofs on One House

The Top Roof Was Hiding the Real One

We tore into a shingle replacement in Colton last week and found two roofs. The top layer was asphalt shingles. Underneath them, the original wood shake, from an old layover job somebody did decades ago instead of a proper tear-off. Shingles laid right over the shake, problem buried, check cashed.

The shake under there was so dry from years of Inland Empire heat that it disintegrated underfoot. My crew would take a step and the layer would crumble under their boots. That is not a roof anymore. That is kindling with a shingle jacket on.

Why Layovers Are a Bad Deal

A layover is when a roofer installs new roofing directly over the old instead of tearing off. It is cheaper on day one, and that is the entire list of advantages. Everything wrong with the old roof stays there, hidden, getting worse where nobody can see it. The new layer ages faster on top of the old one. And when the day of the real tear-off finally comes, you pay to remove two roofs instead of one.

In this house's case, the layover also buried a fire concern. Bone-dry wood shake is exactly what you do not want sitting under your roof in a wildfire region.

You Cannot Shingle Over Skip Sheathing

Here is the part most homeowners have never had explained. Wood shake does not sit on a solid deck. It sits on skip sheathing: spaced boards with gaps between them, because shake needs airflow from below. Asphalt shingles need the opposite, a solid continuous deck under every inch.

So this job could not be a simple swap. It was a full resheet: tear everything off down to the boards, install a new OSB deck over the skip sheathing, cut in ridge ventilation, and then build the new cool-rated shingle system on top of a deck that can actually hold it.

The Part of the Roof You Will Never See

Nobody drives by and admires a deck. The OSB disappears under the underlayment the same day it goes down. But that unseen work is what decides whether the roof lasts. A shingle system is only as good as what it is nailed to. This is the same reason we open up and inspect decking on every tear-off: the surprises live underneath, and finding them during the job costs a lot less than finding them during a storm.

If your home was built mid-century and has ever had a "new roof" that went suspiciously fast, it is worth finding out what is actually up there. Two roofs is one too many.