dry time on wet spray cellulose?
Last wednesday I had the exterior walls of a house I am building sprayed with wet spray cellulose. The framing is 2X6. It is sheathed in 1/2″ plywood and outside of that is 1-1/2″ of xps foam “blue board”. I am in the Hudson Valley region of New York State. How long do you suggest I let the cellulose dry before sheetrocking? I plan to start having the rock hung in 2 weeks. Are there any moisture meter readings that I should use as a guideline. I plan to use the “airtight drywall approach” to prevent infiltration of moist air into the wall cavities during the heating season, so the drywall will be glued or caulked at the floor, ceiling, window and electrical box openings. Because of the way all this is detailed there is a very limited drying potential to the exterior. And once the sheetrock is up there will be a slow drying potential to the interior as well. I have used the “builders guide to cold climates” as the basis for most of these decisions.
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Anyone? Anyone?
Sorry, I don't have an answer for you, but it's only been a few minutes; I'm sure someone will respond. Is there heat in the building?
Edited 5/5/2008 9:18 pm ET by Danno
depends on too many factors to give you an accurate time frame, like temperature, humidity, is heat on, etc.
but, done properly, its not "wet spray" its "damp spray"
When its first done, you can feel the moisture in it just by holding your hand on it, I usually cannot "feel" any moisture after about 2 or 3 days. I usually try to wait about a week before drywalling.
This is IF it was sprayed "damp", not "wet"
The installers seemed to have extensive experience with "damp spray" cellulose. It certainly didn't seem saturated.
harvester.... first... i blow only dens-pak... never wetpack.. so this is just what i WOULD DO :
use a moisture meter with a long set of probes
if the first inch is in the 10 % range
then use a deeper set of pins to find what the outside inch is.. or dig a test hole if you don't have deeper pins
check the moisture of the framing in the attic to determine your ambient moisture
another thing i would do is set up a couple dehumidifiers to speed the process
if you can get the cellulose below 19% it should be good.... there will still be drying to the interior even after you have your gypsum upMike Smith Rhode Island : Design / Build / Repair / Restore
Thanks Mike, I will try to get my hands on a moisture meter.
Damn, now if I had just kept all the insulation links I looked at book marked I could send you to site on that issue.
IIRC a Canadian test was done that showed there was little problem even if it was damp when closed up.
They opened test holes to check for mold etc and found none and no damage.
Sorry I cannot be of more help.
This will bump your post anyway .
Might try googling for the information . Wet spray insulation and moisture tests or maybe moisture problems.
Edited 5/6/2008 2:24 pm by dovetail97128
harvester
issue 160 only says it may take weeks to dry (page 52) they do warn against sealing before dry though.. the article on mold was more complete in this regard, I'll look for it.
did you ask the installers? They might know.
The installers thought it best to wait a day or two at a minimum. The only problems they have ever know of were with jobs where the sheetrockers started the day after they left.
I don't have the heat on. I have all the windows and doors of the house open so there is a good amount of airflow. I am setting up fans as of today. The surface seems very dry to the touch but when I stick a finger in a few inches there is still noticeable moisture.
I would guess that you don't like that answer?
Ask the installer ... or ask the manufacturer for recommendations or a general idea.
Too big a risk not to do it right ... will the installer guarantee it is ready at a certain time? Surely he must have some guidelines to enable him to provide the service.