View Full Version : Multiple siding layers

dan orourke
04-25-2007, 01:04 PM

Richard Stanley
04-25-2007, 02:48 PM
None that I'm aware of - as long as the surface is properly prepared. When it is the only cladding, it is installed over wall sheathing. I have encountered some old applications over gypsum.

Jerry Peck
04-25-2007, 03:53 PM
Is there any requirements from manufactures (or anywhere else) that states
stucco can not be installed over CMU, wood, or hardiplank?

Is it even adivsable to do so?

The BEST stucco application is over masonry or concrete (concrete requires a bonding agent first, though).

Wood? It's done all the time, as in over plywood or OSB with two layers of paper and metal lath for the stucco to key into. Over lap siding? Umm ... if done correctly, it would work, but correctly would be a pain because of the uneven surface of the lap siding, which would allow/cause tears in the paper, so, doing it 'correctly' would be more trouble than simply applying a layer of plywood or OSB over the lap siding and go from there.

Over Hardieplank? I doubt that is sufficient to serve as a substrate for stucco. Plus, there is nothing in the ASTM standards which allows such an installation. You would need to do the same thing as with lap siding, cover with plywood or OSB and go from there.

Of course, as soon as you start building the surface out thicker, you need to start re-flashing everything because the existing flashings are now 'wrong'. Except for stucco over masonry or concrete, that really does not change anything.

Jerry Peck
04-25-2007, 04:08 PM
By the way, Dan ... Thanks

(Multiple siding layers)