Stucco over wood siding?

Hello everyone,

I have a house build in 1993 with pressed board wood siding around the house. The wood siding is on top of plywood and a good amount of the siding got water damage overtime from deferred maintenance and starting to protrude, rot and buldge out. I invited over a stucco contractor I used 8 years ago who did smooth stucco patching at my house and its held up great. He recommended for me to keep the siding on (remove the small area that are damaged/rotted siding) and the inspect plywood. Instead of going traditional stucco, he is insisting to use Omega cement with mesh over existing wood siding and to apply an acrylic stucco on top. He said this is basically what shopping malls and walmart does. The price he is offering is very good considering the other quotes I been getting to remove the siding and do stucco traditional method. What is your take on this process and whether this will hold up in the long term with water and weather.

What do you think would happen when water make its way behind this 2 coat acrylic stucco and reaches your pressboard siding? shopping malls and walmarts don’t have pressboard behind their stucco. The stucco would have to be installed just like it would over bare plywood sheathing with proper WRB, flashing, and accessories. Personally, I would strip the old siding. Whenever a new cladding is installed over old siding, to me, it’s hackish and cheap.


I agree with Simon.


Sounds like your ‘stucco’ guy doesn’t know what he is talking about. What he is suggesting is a disaster in the making. That ‘wood’ siding (already in poor condition) will buckle and warp through the new stucco as soon as any moisture gets in - and it will get in. I can almost guarantee that the exterior will fail and need replacement in the not to distant future with the aforementioned installation details.

1 Like

I am no fan of your contractor’s plan, either. A never-fail stucco system is not casually done and costs $$$ and is worth every penny if stucco is what you want. If you live in a high humidity and more than 17" of annual rain area, then it is even more important.