Cedar Siding Over Asbestos

A brief history of asbestos cement siding.

Cedar siding over asbestos. Removing asbestos is often cost prohibitive for most people. Asbestos cement is a mixture of portland cement reinforced with asbestos fibers. Asbestos was banned in 1989 so as the buildings that incorporated it age their roofing and siding will fall into disrepair. The plastic is used to create a barrier to the elements as well as prevents the siding from rubbing against the painted asbestos siding.

The portland cement binds asbestos fibers into a hard mass. Asbestos cement was first developed in 1905 by the johns manville company who became one of the premier manufacturers of cement asbestos materials. Let the siding dry then prime and paint with the best exterior latex you can find. Many asbestos roofs and siding are damaged cracked or broken.

This can release fibers into the air. It also eliminates the problem of mold forming when insulation is attached directly to the substrate. I ve seen house fires where the vinyl siding burned off only to reveal the superior asbestos shingles underneath which saved the house. Alternatively if you leave the asbestos on your home you can safely seal the old siding underneath the new siding and because asbestos is an excellent insulator you will actually be adding to the energy efficiency of your home by leaving it on.

However removing the asbestos siding first though more expensive is the best alternative in the long run. Was the problem that they put new siding over old or that they put new siding over a rotted wall with no drainage plain in between. If the siding cedar or hardboard is in good shape and the substrate is wood it is foolish to remove the old siding. Nail it in place using several nails a few inches apart until the top of the plastic is fully attached.

Asbestos siding in particular however has a tendency to chip crack and break with normal wear and tear of family life. If the job had been done right the house would have been a total loss. Asbestos shingles are relatively strong but. Lead paint wasn t outlawed until 1978 so it s sure to be present on siding going back to the 1950s.

Going over the existing siding adds to the r value by creating an air space between the insulation and old siding. Place the top edge of the plastic sheeting at the top of the exterior wall above the siding. A common remodeling practice is to install new vinyl or aluminum siding over cement asbestos shingle siding as well as over many other older siding materials when the old siding has become damaged leaky or cosmetically ugly. Covering old asbestos shingles with new siding may seem like an option too but it s not easy to do safely.