Helpful? 0

How to insulate roof?

Hi,

I am renovating this old porch addition and want to insulate it properly. There must have been some moisture issues before because some of the OSB has what looks to be mold or something moisture related. Luckily it doesn't seem to smell and it still feels firm. I'm speaking with a spray foam installer today but I have the feeling that cost for the size of the ceiling (145sq.ft.) is going to be rather... expensive.

These are 2x4 rafters on OSB with a layer of roofing felt and then a corrugated locking steel roof. There should be some ventilation due to the nature of the roof. I've attached some photos. My thoughts are 2x4 batts with a layer of 6mil poly and then 5/8" drywall. The walls have 1" foam on the outside w/ stucco.

If I don't go with spray foam what's my next best option for method and materials?

Thanks for your help.

IMG_20121116_163518.jpg40.72 KB
IMG_20121202_121640.jpg1.44 MB
Asked by benjammin p
Posted Tue, 12/04/2012 - 17:47
Edited Tue, 12/04/2012 - 17:59

Tags:

1 Answer

Select your preferred way to display the comments and click "Save settings" to activate your changes.
1.
Helpful? 0

Benjamin,
I suggest that you read this article: How to Build an Insulated Cathedral Ceiling.

Answered by Martin Holladay, GBA Advisor
Posted Tue, 12/04/2012 - 17:57

Other Questions in Energy efficiency and durability

The differences between mass and insulation

In Green products and materials | Asked by Nathaniel G | Sep 15, 14

Sealing gap between garage floor & drywall?

In Green building techniques | Asked by Robert Hallenbeck | Sep 20, 14

The joys of insulating...

In Green building techniques | Asked by Lucas Durand - 7A | Sep 19, 14

reading new to old

In General questions | Asked by aj builder, Upstate NY Zone 6a | Sep 20, 14

Woodpeckers, Stucco + Exterior Foam with Rainscreen

In Green building techniques | Asked by Brett Sichello | Sep 20, 14
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!