Subject: A few questions about CPES
Date: Sun, 23 Sep
A few questions:
1. I have to replace a foundation sill on my house. Contractors
mention using pressure treated wood (a 6" x 6") and then PT plywood over
the exposed studs. Should I have them treat the sill and plywood with
CPES? Your website appears to say no, but I wanted to make sure. Seems
like it would be an added layer of protection.
CPES will add protection to pressure-treated wood as long as the
pressure-treating isn't fresh (greasy to the feel), in which case the
pressure treating chemistry interferes with the ability of the CPES to
penetrate the wood. So basically, you're right: CPES does add an
additional layer of protection.
An important thing to remember is that once pressure-treated wood is cut
or trimmed, untreated wood is exposed and is subject to rot. Even if you
don't treat all of the wood, those areas that have been cut/trimmed
should certainly be protected.
2. I have to reshingle the part of the house that is getting the
new sill. If I use cedar shingles should I still use CPES?
CPES will protect and consolidate cedar shingles, particularly the
bottom edges that are apt to absorb water. The new farm-raised cedar
does not have the rot-preventing resins that the old original growth
3. How long after using CPES can I paint the shingles?
This will depend somewhat on temperature and air movement, but the
basic answer is that you can paint as soon as the surface is dry to the
touch. This can be in as short a time as a couple of hours, or as long
as 6-7 hours. Certainly you could CPES one day and paint the next.
CPES also serves as a primer for paint.
Thanks. Joe J. MA
You're welcome, and feel free to come back if you have additional