DIY Home Improvement, Remodeling & Repair Forum > DIY Home Improvement > Insulation and Radiant Barriers > Cape Cod Insulation

Help Support House Repair Talk by donating using the link above.
Thread Tools Search this Thread
Old 05-24-2011, 03:54 AM  
Here to learn
Join Date: Jun 2010
Location: N.E. Ohio
Posts: 23
Liked 1 Times on 1 Posts


Originally Posted by Perry525 View Post
At first glance, this is a good idea.
However, you must take water vapor into account!
As you probably know, water vapor is created in the home by cooking, washing, breathing, sweating.
Water vapor once created is held in the air until it meets a cold surface, or if outside meets a patch of colder air, when it turns to rain, etc.
Indoors it heads for the nearest cold surface, which often means straight for the attic where it condenses on the underneath of the roof, possibly leading to mold and wood rot.
If you are going to insulate the roof, you must use at least 3 inch thick polystyrene, or another closed cell insulation, and you must ensure there are no holes or cracks in the polystyrene where the water vapor can gain access to the roof.
Fiberglass and cellulose and other open cell, so called insulation's should not be used as water vapor moves through these with ease and it is impossible to make an air tight surface.
After you have filled the spaces between the rafters you should then add another layer of polystyrene below the rafters to stop the water vapor from condensing on them.
I'll have to ask my friend about that. He also deals with mold inspection, and water vapor issues certainly fall within that realm.
Without being any kind of expert on it myself, I would agree that poly foam is a lot better than batting, but also a lot more expensive when getting R-value bang for your buck.

Once again, there are a ton of ways to address the same concern and it is difficult to decide which is the best choice. Ahh, the joys of being a homeowner.

Last edited by head-first; 05-24-2011 at 03:58 AM.
head-first is offline  
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Similar Threads
Thread Thread Starter DIY Home Repair Forum Replies Last Post
Cape Cod Fitz31 Insulation and Radiant Barriers 1 04-29-2014 11:28 AM
Anybody from Cape May? Wuzzat? General Chit-Chat 1 10-30-2012 03:00 AM
Cape cod insulation question centaurette Insulation and Radiant Barriers 21 03-13-2012 10:04 AM
What to do, with a Cape Cod? chipraynor Framing and Foundation 2 02-09-2011 08:39 PM
hi from cape cod. new to the site marl19 Introductions 1 01-03-2009 04:45 PM

Newest Threads