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'bubble' in drywall next to wall heater

Santa Rosa, CA(Zone 9b)


This is my first home, so I am slowly learning how to take care of and repair things. :) Last weekend we painting our living room, dining room and kitchen. (its a small house). In the process we discovered a large 'bubble' forming in the drywal next to a gas wall heater.

I don't know the first thing to do to fix this, or more importantly find out the cause. I am concerned that it may be some sort of water leak. But I see no other signs of a problem. The ceiling above the area is fine, the wall and ceiling behind the heater (its a double sided heater) appear normal.

Can some kind soul point me in the right direction to getting an answer for the cause and then getting it repaired. Can I fix it myself?

When I touche the bubble it does give a little, Im sure with a bit more force I would punch a hole in the wall/drywall. I dont want to do that - until I have to :)

Thumbnail by blackThumbz
Long Beach, CA(Zone 10a)

Difficult to tell from the photo, (not your fault, though ) but if you haven't had a water leak anywhere, it could be one of two things, or both:

1.) The vetical line that is to the left of the bubble MAY just be a seam in the joint of the drywall where the tape and "mud" (drywall compond used to fill in the joints/seams) didn't quite take or just came loose.

2.) The bubble itself MAY be the result of when the opening was made for the wall heater installation...and air got in there.

Try scraping the vertical bubble and see what's inder it. You might find the seam tape...which could either be white or a mesh type tape that is yellow. IF it appears to be loose (and DRY) try removing it gently up to the point where the bubble starts, then take a razor blade and cut it off. You can replace the bad section and put new tape mud over it to smooth it out. Be careful to pack it in firmly and smooth it out so it's flush. Let it dry, the sand it flush, prime it and repaint it.

IF your walls are textured, it will be difficult to match the stipple you may want to have someone who knows drywall do the repair for you. IF they're smooth, it shouldn't be a problem.

As far as the big bubble right next to the heater, you really won't know until you open it up and see what's under it.

If your walls are textured, (sometimes the drywall installers will spray on a fine textured finish, sometimes not ) it's very difficult to match that texture without having the sprayer that did it initally. If you smooth out the patch with a putty knife, it will show through after it's been painted and be pretty proceed carefully.

Fallbrook, CA(Zone 10b)

First thing you need to do is open up the bubble. With a razor knife cut around it and remove the surface. Check to see if there appears to be any moisture. If so, you'll need to get into the attic to find the source. If not, it could be heat related, being as near the wall furnace as it is, or just a bad seam from a previous repair.

Getting to the repair; you'll need to brush out all loose drywall debris, sandpaper the edges with 120 grit sandpaper and prime the surface with a sealer. My preference is KILZ 2, a water soluble latex multi-purpose primer. It needs a couple of hours at most to dry. If the indentation is 1/4 inch or less, you can probably do this in one application. Use a 6 inch flexible broad knife,(putty knife or scraper) put a coat of drywall (sheetrock) mud into the gap and smooth it out with one long stroke. You'll need to 'feather' it back from the edges toward the center vertically. Get it as smooth as possible, but ensure that the finished mud is equal in "height" to the surrounding surface. The patch should be 6 to 10 inches wide. Wait 24 hours for proper drying!!!

Assure there's no gaps or shrinkage below the average wall surface, if so, re-apply to fill the gap. After proper drying time, use 80 grit sandpaper to smooth the patch and about an inch or so of the surrounding wall.

It appears you have a "knock-down" texture on the walls. It is not that difficult to duplicate. There is an aerosol spray texture available at most home centers (Homax is a popular brand) It costs 12 to 15 dollars and will do a patch the size of the one you have 5 or 6 times. You'll need to purchase a 14 inch drywall mud
knife for the knock-down process. Use the instructions on the can and play around with it until you get it to look the way you want it. You may end up using the whole can on this patch, but it's valuable experience for the inevitable future patch jobs.

Good luck and congratulations on your new home.

Edited to say:
Of course you'll need to prime coat and paint the patch when finished.

This message was edited Apr 19, 2009 10:58 AM

Santa Rosa, CA(Zone 9b)

So, I have been cutting and removing the bubble, I see from my new pics, I still need to remove a bit more from the top.

I see no seem under what I removed, in fact it's in excellent condition underneath. So I am leaning toward some sort of air pocket.

It looks like there was a patch done to the left of the heater. And this area was allowing air to get in?
I just recently noticed this after our first winter in the house.

When we purchased it in September of 2008 This bubble did not exist. I am 100% sure of that. I dont know when it started. We just noticed it when we painted.

Do I still use the join tape? Or do I just re-fill with joint compound? And that's joint compound - not spackle, correct? Whats the difference? :)

Thank you bth for your time and guidance.

Thumbnail by blackThumbz
Santa Rosa, CA(Zone 9b)

Heres a close up of the initial patch job around the heater. I think this is where it initiated.
The picture is kinda dark - sorry I tried to lighten it.

Thumbnail by blackThumbz
Fallbrook, CA(Zone 10b)

No need for tape. Just fill in with drywall mud. (what you're calling joint compound)

Joint compound and spackle are very similar, however, spackle has a lot more acrylic in it and dries much harder. It's also less apt to shrink as much as joint compound because it has less water in it. But spackle is much harder to work with in a large area like you have. It's more suited to filling nail holes and other small problems. Spackle is also 10 times the cost.

This message was edited Apr 20, 2009 11:08 AM

This message was edited Apr 20, 2009 11:10 AM

Santa Rosa, CA(Zone 9b)

Ok here's an update - fascinating stuff here. So I have purchased and applied the knockdown. But I am not going to knock-it-down. It looks really close to me. With some paint you may never even know there was a bubble to begin with.

Here's a pic of the drying knockdown. I think a decent coat of paint and we will never know.

Thanks again for the help!

Thumbnail by blackThumbz
Fallbrook, CA(Zone 10b)

Looks very nice. Now you're a pro.

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