Permatek Shake Roof Repair Guide
Maintain Permatek Asbestos-Cement Roofing

How To Repair Permatek Shake Roof Damage

Reader question: On 8/3/2023, Alistar asked: recommended adhesive products for repairing Permatek shakes?

Are there any adhesive-type products (such as caulking, etc.) recommended for repairing Permatek shakes ( composite of Portland cement and wood fibers)?

Photo: broken and lost piece of a Permatek roofing shake near a roof valley.

[Click to enlarge any image]

This discussion was posted originally

at ASBESTOS & FIBER CEMENT ROOFING

Reply: Silicone sealants may work best but first assess extent of roof damage

Thank you for a helpful question: repair methods & sealants for Permatek shake roofing.

While the composition of Permatek shakes (as you point out, portland cement and wood fibers) is a bit different from cement-asbestos shingles, some helpful repair suggestions are at

ASBESTOS CEMENT ROOF REPAIR

Just what repair method is needed for your Permatek shake roof depends on a more specific description of just what damage is being addressed.

For a split or broken or missing individual shake, a durable if cosmetically imperfect repair is to slip up colored metal flashing under the broken shingle so that the head or up-roof edge of the flashing is under the course of shingles above.

Above: edge view of broken piece of Permatek shake roof tile.

Small Permatek shake roof repairs of broken pieces might be made with a silicone sealant.

Choose one that is close in color to the shingle color. But for this repair to work, the surfaces being glued or sealed must be free of dirt and debris, dry, and must not be swollen and so soft or friable that the shake is actually disintegrating.

For disintegrating Permatek shakes over larger roof areas, my OPINION is it's time to replace the roof, but some people have tried extending their roof life using a spray-on rubber roof coating over the entire roof.

I am not optimistic about that sort of "roof coating" repair for Permatek nor for American Cemwood roofs. I think that once the underlying shingle material has become soft and is fragmenting or shedding, there is a good chance that the roof coating is going to begin to peel and flake off, giving a short life for a rather expensive "roof repair" job.

And I think you'll find that companies offering such roof coating treatments may not warrant that job on asbestos cement, fiber cement, Permatek, American Cemwood and similar roofs.

Please add some details about your roof condition: just what repairs are needed and over what area, and post some photos - one per comment - so use additional comments for additional photos - so that we can see what's going on with your roof.

On 2023-08-03 by Alistar - Repair methods & sealants for Permatek shake roofing.

Repair methods & sealants for Permatek shake roofing.

Thanks for your reply. I cannot reply to your message above so I am simply writing a new message, which is odd because when I originally read your reply there was a box where I could reply...was that meant to disappear?

Here is are several images of the Permatek shingles. [Shown both above and below on this page - Ed.]

Below: cracked Permatek roofing shake and another Permatek shake with a hole that needs patching.

98% of the roof is OK, we just want to address the 25 or so shingles that are cracking.

Also, what adhesive/sealant was originally approved for flashing purposes with these shingles? Would that not be a good repair material?

On 2023-08-04 by Alistar

@DF,

This website is confusing me. At one point I saw a "reply button" but that has disappeared. Thanks for your replies.

After looking at my pictures, do you still recommend silicone?

Alistar

On 2023-08-04 by InspectApedia Publisher (mod) - how to repair a Permatek shake roof without causing further damage

@Alistar,

Thank you for these excellent cementious roof tile photos.

Key in repairing this sort of roof is avoiding causing more damage by stepping onto the shingles/tiles.

For repairs in areas that can't be reached from roof edge an experienced contractor may suspend one or more ladders hung down from the ridge, and padded off of the roof deck. Then the worker just works from the ladder itself, moving it along the ridge as needed. Or a pair of ladders with roof jacks can allow temporary scaffolding.

For a shingle/tile that's mostly intact but has a partial crack I might try cleaning the crack and using a gray silicone sealant as I mentioned earlier. You shouldn't need a big ugly blob, and the flexibility of the sealant may better tolerate thermal movement in the roof material.

That's the same for the hole in a Permatek shake in your photo.

Where an entire shake section is missing, a functional, if not so cosmetically lovely, repair is as I suggested, slip a segment of metal flashing up high under the shake above so that you are safe from leaks.

Then if you want to try gluing in a patch with sealant you can do so.

These roof repair articles are worth reading when repairing Permatek shake roofing as well since these articles give more details about temporary and more permanent repairs on fragile roof surfaces like Permatek shakes.

First see

ASBESTOS CEMENT ROOF REPAIR

also review the working methods for fragile roof materials that we explain at

SLATE ROOF REPAIRS

and

SLATE ROOF LEAKS, TEMPORARY REPAIR

Also,

at SLATE ROOF SOURCES & TOOLS

we describe special tools that aid in removing a broken slate or tile to permit slipping a new one into place, held by one of two fastener methods that we also explain in those articles.

Certainly when most of the roof, 98% by your estimate, is in good shape, it's well worth working carefully to repair the few areas of damage.

Don't hesitate to post more photos, questions, or comments. All of this will be helpful to other readers who need to repair Permatek shake roofing.

About using silicone, on a Permatek roof:

There are probably other adhesive-sealants that can work well on a Permatex shake roof provided you've cleaned the surfaces, but there are several reasons I recommended silicone.

It is among the most adhesive sealants, available in colors close to your roof color, can be worked into a crack or hole, and will remain flexible - important on a roof surface that is likely to move a bit due to thermal expansion and contraction, and of course it's totally waterproof.

I steered away from more cementious patch materials that might seem obvious because of the thermal movement concern.

About what adhesive/sealant was originally approved for flashing purposes with these shingles?

Asbestos cement roofing systems producers did not recommend reliance on adhesives or sealants "for flashing purposes" - rather you should be using metal flashing at roof penetrations.

Below: tip on posting multiple comments at InspectApedia.com

More about posting comments, After you've posted a comment the comment box disappears, but you'll see a rectangle stating "Post Another Comment" (shown in my screen shot below) - click that rectangle and the comment box reappears ready for use.

And below any reader or moderator comment that has posted, there are three options to Like, Reply, or Flag. By clicking on Reply, you can respond to a current comment thread.