drywall over drywall

DEBORAH2 · 09-04-2011, 03:45 AM

i plan to insert foam insulation in holes of the old drywall , and finish with a new drywall sheet over the old, now filled with foam. i don't need a plastic sheet right? do i need a space in between? or can i just mate them together?

**oh'mike** · 09-04-2011, 07:19 AM

No plastic needed to overlay drywall---just drywall adhesive and screws.

DangerMouse · 09-04-2011, 08:23 AM

Quote:

Originally Posted by DEBORAH2

i plan to insert foam insulation in holes of the old drywall

How do you plan on doing this? Spray foam?
I would be very concerned with expansion bulging the drywall.
Of course, I could be wrong about your intention.

DM

epson · 09-04-2011, 08:36 AM

If she does use spry foam to fill in the holes, she can trim off the excess flush to the drywall after the foam expands and hardens. Then she can place the drywall on top without worry about bulging.

DangerMouse · 09-04-2011, 08:49 AM

One of us must be misunderstand. I was thinking she wanted to add insulation inside empty walls, but perhaps you are correct and she's simply repairing holes? But.... why repair holes if you intend to drywall over them?

DM

epson · 09-04-2011, 09:11 AM

I guess so there wouldn’t be any voids in the drywall before installing new drywall over It.?

DEBORAH2 · 09-05-2011, 12:39 AM

since my home has only foam outside, then siding, and my energy bills aqre so high, i checked in to foam it green and decided i cut the original drywall centers out, let the foam expand out towaqrds the in side of the house, then trim it off flush with a giant samurai looking foam knife. then to make it look pretty again, install another later of 1/2 in ch over the top. this ok??

gregzoll · 09-05-2011, 03:14 AM

Deborah2, what you are wanting to do, is not going to work. As for high energy bills, is there already Fiberglass batts behind the drywall that is already there? Are gaps and seals around windows, outlets, light switches, sealed? Does the attic space have the proper insulation level, along with proper venting? How old are the mechanicals in this place (ie hvac- Central air & furnace), along with what type of fuel for heating? What are you using to compare what you are paying, in determining your bills to heat and cool, compared to others? How old is the place? What kind of doors & windows are in this place?

There is more to cutting costs, than just wanting to do what you are thinking, that may cut energy bills.

DangerMouse · 09-05-2011, 07:45 AM

Quote:

Originally Posted by gregzoll

Deborah2, what you are wanting to do, is not going to work.

Why not?

DM

**oh'mike** · 09-05-2011, 07:55 AM

Can you post a picture? I'm confused---

gregzoll · 09-05-2011, 11:13 AM

The mouse, because it would be too much work, and would look like a bandaid on a hooptie.

chrisBC · 09-08-2011, 01:43 AM

if you want to spray foam your wall cavities (which as far as I can tell is what you want to do, I have to admit i'm not positive though)

then really you should remove all your batt insulation, and do all the other prep necessary. I would think a lot more drywall would be removed other than a few holes. Either that or pull the siding off.

I would think it would be a easier to remove most if not all the drywall, considering you will have to board/tape/mud the whole area anyways if you go over, and make it a lot easier to take out your insulation. If you really want to spray foam. As well if you add a second layer keep in mind all your door/window trim along that wall will have to be dealt with now that a 1/2 inch has been added, if the returns are trimmed with wood. By the time you make a large enough hole for every wall cavity, may as well just take it off.

Just make sure you know the cost involved with what you are talking about before getting into it, it's not a small job.