vented cathedral ceiling with NOT so dense pack insulation
dirkgently
| Posted in General Questions on
Hi all,
I am trying to anticipate problems with a vented cathedral ceiling assembly which will have 14″ off dense pack cellulose in the rafter bays.
Assuming there is a verified air barrier on the underside of the rafters….what is the worst that can happen if the cellulose is not installed perfectly to dense pack standards?
In northern New England (zone 6) we are lucky to have many cellulose installers…..but not all of them are perfect…..and in other areas of the country there seems to be a real lack of experienced installers.
Thanks
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Replies
In a vented assembly you should be fine--venting makes up for a multitude of sins. If the assembly was not vented, the borates in the cellulose protect whatever they are touching, preventing microbial action that leads to rot, so settling leaves the sheathing vulnerable. But venting whisks away any moisture before it can cause problems. Loose-blown cellulose actually has slightly higher R per inch than dense-packed cellulose.
Thanks Mike, I am honored such a famous author replied to my question. Loved the book BTW.
I had wondered if the chemicals in cellulose would help protect from mold...2 answers to one post, my lucky day.