On Sunday, July 21, 2013 10:36:48 PM UTC-4, leza wang wrote:
Hi

I had fake brick (faux brick) for the front of the house. They put the fake brick on the plywood without mesh or anything!! just the fake brick and cements. We removed all the bricks, now it is only plywood and it is an old one and few places are rotten (back) (I will post pictures). I am going to put a wood panel (from home depot called Smart panel. it is wood siding basically).



My question, should i treat the plywood with something to make it better or fix any damage etc before I put the wood panels?

If the plywood is rotted, then of course you have to replace
the rotted sections, unless you want the new siding to fall off.
Tyvek should go over the plywood before the new siding goes on.



I am not going to put any isolation because the siding of the house which were done the same way, i do not think they use isolation.

Hopefully there is insulation and a vapor barrier in the
wall cavity. But from what we've seen so far, I wouldn't bet
on it. That is how it should be done. I guess if there isn't
any or there isn't enough, you could put some kind of rigid
insulation under the siding, but I have no experience with that.
Plus, I would think it would create all kinds of problems, like
how do you deal with the increased thickness, ie siding will not
line up with windows, doors, etc.




But my concern now, do I need to treat the plywood with a certain material..



Thanks a lot

No, you don't treat it. Typically, CDX grade plywood or OSB is
used. But I'd say one thing that should be determined is in the
areas where the plywood failed, why did it fail? If it was because
the faux brick wasn't installed correctly and let water in, then
you're fixing that. If it rotted for some other reason, that
hasn't been addressed, then it needs to be, otherwise the new
plywood will rot too. Bottom line, if the construction is done
correctly, plywood is protected and won't rot. I just pulled some
siding off my house, at 30 years, the sheathing is still perfect.