What Is That Slate Siding On My House?

 

I was chatting with a house painting contractor recently who had an interesting question. " I've been asked to give a bid on painting a house with asbestos shingle siding (probably from the late 40's or early 50's) and a number of shingles are cracked or broken.  I doubt if one can buy these shingle anymore and I was wondering if you know of any satisfactory replacement product.   Would any special precaution be needed in removing the old broken shingles?  The shingles have never been painted, would they require a special primer or special paint?"

Personally, I like to have a little asbestos in my cereal in the morning---great fiber. I'm kidding of course, but once again, common sense should be our guide.

The siding he's talking about is likely called Transite and was manufactured in Canada from the 1920's through the 1950's. It is a cement board product that used asbestos as a binder for the cement. This product was made as roof shingles and siding that tried to look like wood shingles. It is on hundreds of thousands of older homes.

Asbestos cement siding was popular in an era when InsulBrick was also an option for replacement siding for old houses. This was that tar paper looking brick, very fashionable. The truth is, you can partially track the downfall of neighborhoods by when replacement siding materials like Transite, InsulBrick, aluminum and now vinyl were installed. It's a sign that homeowners are unwilling or unable to maintain their homes properly. The maintenance problems don't go away, they just get covered over and aloud to worsen, sight unseen.

The good news is that it's non-friable in place. This means it generally doesn't have loose fibers that can escape, causing lung damage. Repairing damaged and broken pieces is possible as long as you are cautious. There may be some loose fibers around the broken pieces. You must thoroughly wet down the broken pieces with water before you carefully remove them. You may not need to remove them if you follow a couple of my repair techniques.

Broken or cracked pieces can usually be caulked or actually glued back together with epoxy right in place. If little pieces are missing, repair the holes with architectural, exterior grade epoxy putties. You should fill the areas a little higher than the surface and then shape it with chisels and other hand tools to match the surrounding piece. Don't disturb the original shingle by sanding or grinding the epoxy as that could wake the asbestos up (make it friable) and release it into the air.

If you have whole pieces of siding completely missing, the James Hardie Company (www.jameshardie.com) makes modern day cement board products. They tend to be a little thicker but they still have the embossed wood grain on their face (isn't it amazing that most synthetic replacement siding products want to pretend they're the real deal and so they emboss fake wood grain onto their products-hmm).

Most architectural salvage outfits avoid saving Transite like the plague. The new products use some non-asbestos binder. Here's what the Environmental Protection Agency (EPA) has to say about it.

"Non-friable materials, such as transite siding and floor tiles are not regulated provided it does not become friable. Machine grinding, sanding and dry-buffing are ways of causing non-friable materials to become friable."

This is a big turnaround for the EPA. In the past they wanted asbestos out of and off every structure. They were more like the Environmental Panic Agency in years past. Their new panic is lead paint and their reaction to this issue is totally out of proportion to the problem. They're even trying to ban modern oil based paints. In Illinois, try to buy some alkyd oil based primer or oil based varnish. The idea is to eliminate high VOC's (volitale organic compounds) and therby help the environment. The problem, in my opinion, is that water based products just don't hold up as well as oil. I'm sure calmer heads will prevail and we'll find some middle ground.

Transite siding was about the only decent replacement siding ever on the market. It was rarely installed over moisture trapping backer/insulation board and is rigid enough to allow a transfer of air. As a result, the original siding underneath rarely has any damage beyond the day the Transite was installed.

It also holds paint wonderfully as long it's painted with oil primer and oil paint. In my experience, Transite will hold paint without peeling for 30 to 40 years. It may fade and wear from the weather but I've not seen it peel. I feel these new cement board siding materials will have similar paint longevity as well.

Finally, I've removed Transite siding from so many historic houses I've lost track. As a homeowner you have every legal right to remove this and go back to your beautiful, original exterior. Wet down the siding with a hose and carefully remove the pieces. Keep it very wet and even if you break a few, the water will hold down the fibers. Your local waste company will send out a dumpster with a special liner and signage for asbestos. It will cost a little more than a regular dumpster but it worth it. Keep the layers of Transite in the dumpster wet as you go along.

If you don't want to do this yourself, hire a certified and licensed abatement contractor to remove it. These are the guys in the moon suits etc. This can be very expensive and since Transite in place is not friable you may be better off just leaving it.

I have to go finish my cereal now.