Foam Board Over Drywall...

[Surfr]

What's up guys! And ladies...

So I have a freshly sheet rocked 20'x20' room. I'm going to be installing 3/4" foam board over the drywall for further sealing and insulation. Should I coat the drywall before throwing the foam board up?

 

[Freshone]

I would shoot that drywall with a coat or two of kilz primer just for a good seal and it's anti microbial qualities,moisture could build between the foam and sheetrock if not sealed 100%.

 

[1diesel1]

Foam board? Rigid ISO, styrofoam?

 

[Bulldog420]

insulation is suppose to go in the wall......Not over the sheetrock.........

Your sheetrock should be mud and taped with all holes filled. This will give you a manditory 1 hour fire rating. (assuming you also bought a 90 min fire door) Then if you feel like it, put up the foam board. I would have used r-13 in the walls. (assuming they are 2x4)

 

[Surfr]

The walls have been completely sprayfoamed. I just have 100 sheets of 3/4" rigid laying around so I figured why not? My original plan and what I have always done is coat everything with Kilz so I'll just stick to that

 

[Dunge]

The walls have been completely sprayfoamed. I just have 100 sheets of 3/4" rigid laying around so I figured why not?

Waste of foam.
Fire hazard.
Makes room smaller not better.
But most of all, it serves NO purpose.

 

[Surfr]

So there are no insulation properties to rigid?

 

[Bulldog420]

Use them as dry rooms or something. Tape them together and make cubes.

However Dunge hit the nail on the head.

 

[Surfr]

Well now I'm curious as to why it wouldn't add insulation value to the room if installed? I'm not saying I'm going to install it.. I'm just curious.

 

[DrMcSkunkins]

Use them as dry rooms or something. Tape them together and make cubes.

However Dunge hit the nail on the head.

Duct tape foam board mini flower rooms

 

[Homesteader]

The foam will add insulation value (3/4" =r4 or r5?) however in the event of a fire, the foam creates massive amounts of noxious gas and smoke. This is why it is best used against concrete and behind a framed wall filled with fiberglass batt insulation and taped and mudded Sheetrock.

 

[str8smokn]

I don't think they are saying it wouldn't insulate more, just that it's a waste and takes up space from room
STR8

 

[Seamaiden]

I don't see why it wouldn't, its insulation. Anything that limits the tranfer of heat will provide r-value. Probably be a bitch to clean tho. Or if you're doing surface mount electrical....:D

Actually, I used those to make the walls of my old indoor room and they clean up great.

 

[keiksweat]

Got my whole loft area done in it.works great.cooler in summer.hotter in winter.

 

[AvidLerner]

rigid insulation has an r-value of 2.5 per inch. I use it for sculpting walls thicker, creating deep recesses, and insulating exterior walls. 2" is a great insulator. If you get the silver faced, you get a freebie, it reflects better than most surfaces and easy to clean too. A layer of kilz is great too. great idea, will keep the heat out or in as you desire. peace