Insulation, Radiant and Vapor Barriers - Warm side of wall
Doityourself.com community forum was created to provide answers to all questions related to home improvement and home repair. Doityourself community can help you find information about how-to topics on small fixes to large remodeling projects. With comprehensive how-to content and expertly moderated community forums DoItYourself.com makes it easy to tackle even the most complex home improvement projects.View Full Version : Warm side of wall
suobs
08-30-09, 06:53 AM
I'm finishing the inteior of a garage/shop and before installing the interior sheet goods I want to insulate it so I can put in A/C in the future (2-3 years from now). It's detached from the house and is 2x6 framing with T1-11 siding directly over builder's paper, no additional sheathing. I want to finish the interior walls with pegboard. I have a few questions:
1) Batt fiberglass insulation with a backing - is the backing a vapor barrier?
2) Fiberglass insulation usually says to install the backing on the warm side of the wall. In Florida with A/C, wouldn't that be the outside of the wall, directly against the builder's paper?
3) Do I need an additional vapor barrier on the inside of the wall (plastic), directly under the pegboard sheets?
1) Batt fiberglass insulation with a backing - is the backing a vapor barrier?
2) Fiberglass insulation usually says to install the backing on the warm side of the wall. In Florida with A/C, wouldn't that be the outside of the wall, directly against the builder's paper?
3) Do I need an additional vapor barrier on the inside of the wall (plastic), directly under the pegboard sheets?
airman.1994
08-30-09, 08:10 AM
Paper is not a VB. Plastic VB on inside of wall.
GBR in WA
08-30-09, 05:01 PM
"Moisture movement by vapor diffusion from the exterior can be controlled by the use of exterior vapor retarders in walls, roofs, and crawlspaces. Moisture movement by vapor diffusion from the interior is not a concern in hot-humid or hot climates—interior vapor retarders are unnecessary and should avoided." BSD-012: Moisture Control for New Residential Buildings — (http://www.buildingscience.com/documents/digests/bsd-012-moisture-control-for-new-residential-buildings?full_view=1)
About half-way down, for hot-moist climates. Read the whole article, vapor retarders, etc.
Be safe, G
About half-way down, for hot-moist climates. Read the whole article, vapor retarders, etc.
Be safe, G
Perry525
09-01-09, 10:47 AM
Fibreglass is rubbish and should not be installed in a wall, it tends to sag over time and this leaves holes in the insulation, also fibreglass allows water vapour to enter its fabric and becoming damp this stops it being an insulation.
The best insulation is tightly fitted polystyrene or similar closed cell insulation, this provides three times the amount (or more) of insulation for the same thickness and it is almost waterproof and windproof.
Water vapour always moves from hot to cold, so where the inside of a home is cooler than the outside then the water vapour barrier is placed under the outer skin. In areas where the outside is colder it goes on the inside.
The best insulation is tightly fitted polystyrene or similar closed cell insulation, this provides three times the amount (or more) of insulation for the same thickness and it is almost waterproof and windproof.
Water vapour always moves from hot to cold, so where the inside of a home is cooler than the outside then the water vapour barrier is placed under the outer skin. In areas where the outside is colder it goes on the inside.