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workaholic · 01-17-13, 11:38 AM

here is the latest version of my project

My son and I went over last night and added 2x2's to the walls to make them 7" deep. Since I have 8" insulation I may as well get the full benefit of it.

I am now planning to use the "airtight drywall system" inside.
I still plan to put 1/2'' foil faced foam on the outside of the block wall between the girts.

The girts are already glued and screwed to the outside of the block wall.

I plan to glue the foam (already bought on sale) to the blocks and caulk around it to seal it to the girts. Do you think this will act as a vopor barrier on the outside?

If the corrugated metal is properly installed it will keep all rainwater out and is non-porous so it will not absorb and store moisture.

So the only moisture between the steel and the block walls will be from humidity in the air?

If the foil faced foam glued and sealed to the outside of the blocks acts as a vapor barrier there shouldn't be much chance of the sun driving moisture into the wall except maybe through the 2x4 girts.

I recognize that my block walls will still be colder in winter than interior air.

Do you think that the interior drywall system, without vapor barrier, will keep enough moisture out of the 8" fiberglass insulated wall to prevent condensation on the inside of the concret blocks? If not; would increasing the thickness of the foam glued to the outside of the block to 1-1/2" stop it?

Would it be better to not have any kind of vapor barrier on the outside so moisture in the framed inside wall could migrate both ways?

A lot of questions and dubious assumptions I guess; but I am currently suffering from "analysis paralysis"

Once agian Thanks for the help

01-17-13, 11:38 AM	#22
workaholic Lurking Renovator Join Date: Jan 2011 Location: evansville, indiana Posts: 18 Thanks: 1 Thanked 1 Time in 1 Post	here is the latest version of my project My son and I went over last night and added 2x2's to the walls to make them 7" deep. Since I have 8" insulation I may as well get the full benefit of it. I am now planning to use the "airtight drywall system" inside. I still plan to put 1/2'' foil faced foam on the outside of the block wall between the girts. The girts are already glued and screwed to the outside of the block wall. I plan to glue the foam (already bought on sale) to the blocks and caulk around it to seal it to the girts. Do you think this will act as a vopor barrier on the outside? If the corrugated metal is properly installed it will keep all rainwater out and is non-porous so it will not absorb and store moisture. So the only moisture between the steel and the block walls will be from humidity in the air? If the foil faced foam glued and sealed to the outside of the blocks acts as a vapor barrier there shouldn't be much chance of the sun driving moisture into the wall except maybe through the 2x4 girts. I recognize that my block walls will still be colder in winter than interior air. Do you think that the interior drywall system, without vapor barrier, will keep enough moisture out of the 8" fiberglass insulated wall to prevent condensation on the inside of the concret blocks? If not; would increasing the thickness of the foam glued to the outside of the block to 1-1/2" stop it? Would it be better to not have any kind of vapor barrier on the outside so moisture in the framed inside wall could migrate both ways? A lot of questions and dubious assumptions I guess; but I am currently suffering from "analysis paralysis" Once agian Thanks for the help __________________ If there are two ways to do a job always choose the hardest; it'll take twice as long but you will learn twice as much.