Exposed gypsum core? What's the issue?

Reply

  #1  
Old 11-28-19, 01:09 PM
Member
Thread Starter
Join Date: Nov 2019
Posts: 3
Received 0 Votes on 0 Posts
Exposed gypsum core? What's the issue?

About to work on a small 2nd floor laundry room in a condo built in 1979. Noticed that near the baseboard there were patches of paint bulging/bubbling. I took a 5-in-1 to the area and paint/cardboard/etc came right off with minimal force. Did I expose the gypsum core of the sheetrock (see images)? What caused this and how do I correct? Note that if I keep peeling at the bulges the cardboard-like material just keeps coming off. Also, there's the rusty nail in the photo as well - figured it's from the high humidity of the laundry. New DIY-er here - any help is appreciated.
 
Attached Images   
Sponsored Links
  #2  
Old 11-28-19, 01:27 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 23,502
Received 244 Votes on 225 Posts
Welcome! Dont know where you live or how cold it gets there but high humidity and condensation in cold temps can cause the paper to separate from the gypsum. You get a lot of cold air coming under the bottom plate in winter months and so the problem is usually confined to the area behind / around the baseboards.

Similar problem in hot humid climates but it's the humid outside air hitting the colder air conditioned air inside that can cause the condensation.

You probably need to remove the baseboard and cut off whatever is loose. You usually want to prime it with an oil primer like Kilz original and let it dry before you attempt to patch it. Durabond or lightweight setting compound is usually a good idea for your first couple coats. Paper or fiberglass tape should usually be embedded along the edge of your repair on your first coat.

Or if it's too soft to patch, you could always cut out and completely replace the drywall.
 
  #3  
Old 11-28-19, 02:03 PM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 46,271
Received 141 Votes on 126 Posts
If you don't want to use an oil base primer you can use Zinnser's Gardz instead.

While you want to remove what paper is loose you don't want to remove more than you need to. Scoring around the area with a utility knife first will help limit how far the paper pulls off.
 
  #4  
Old 11-29-19, 05:10 PM
Member
Join Date: Jul 2003
Location: California
Posts: 1,812
Received 2 Votes on 2 Posts
How thick is the cardboardy stuff? It looks like celotex or something like it. Is this wall shared with an adjacent unit? Is it an exterior wall? I wonder if this is an attempt at soundproofing. I think if it comes off easily I would be for taking it off and replacing with new drywall but what to nail to?
 
  #5  
Old 11-30-19, 01:18 AM
Member
Thread Starter
Join Date: Nov 2019
Posts: 3
Received 0 Votes on 0 Posts
It's very thin - about 1/16 of an inch. And yes, the laundry room sits both adjacent to a bedroom in my unit as well as the laundry room in the other unit. I was also wonder what the sound proofing mechanism would be given where the laundry room is located.
 
  #6  
Old 11-30-19, 11:08 AM
Member
Join Date: Jul 2003
Location: California
Posts: 1,812
Received 2 Votes on 2 Posts
I've never seen the paper on ordinary drywall look so fibery. Are you in the US?
Any chance the washer hookups or drain are above the damaged area?
If the paper or cardboardy stuff is adhered to the gypsum core then I would leave it. Without that facing, whatever it is there is no strength to the gypsum. For stuff like this I use FibaFuse scrim. It comes in long rolls 3' wide or maybe it's 1 meter wide. I mix up some 5 minute mud and embed the scrim into that then add more on top of the scrim. Wait until it sets and add another or more coats until it is built out flush. But if this is otherwise conventional drywall I think I would opt for replacing the area. the caulked or painted with buildup of the baseboard might be an irritating issue.
 
  #7  
Old 12-01-19, 05:36 PM
Member
Thread Starter
Join Date: Nov 2019
Posts: 3
Received 0 Votes on 0 Posts
Yes, I'm in the southwestern US. And yes, the hookups are directly above the area.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: