Note: the below image is distorted (curved lines) because of the panoramic picture)

I had old tiles in the remote corner showed in this picture. Those came off the wall taking the drywall with them. As I was trying to put the drywall back I noticed that there was a 1/4" gap between the wall and the drywall at the bottom of the drywall that was still attached to the wall and I realized it will be very difficult to match that exact gap, keep the wall plumb (it was not plumb anyway) and install tiles there.
After a closer look to the wall I realized there was a long and narrow piece of drywall installed horizontally and that was tilted in a strange way so I wanted to check what was there and I removed that and the result is what is in the picture below

The drywall is covering two sections of the same cinder block wall (this is an interior wall in the basement, load bearing, rooms on both side The room I am working in is an old bathroom that went through 2-3 renos over 60Y and each round added more patch work and more corners were cut.

In this case the bottom right section of the wall was completely unfinished so they installed 1/4" plywood strips to bring it to the same level as the left side but that did not work quite well and not sure why they ended up doing wet shimming but on the left side; I suspect that they screwed the right side of the sheet and since the furring strips were not level with the left side that pushed the drywall toward the center of the roomat the left side of the panel when they screwed the right side (it pivoted a little). So what they did to fix that was to add wet mud behind the drywall board on the left side that was 1/4" away of the wall

I am now paying the price and I am trying to fix this bad work. My plan is to bring the furring strips level with the left side (the finished side of the cinder block wall) and then to put the drywall back. They attached the drywall directly to the wall by pre drilling holes and stuffing them with copper wire and then they used drywall screws to attach the drywall. Is there a better way to do this ? Tapcon screws??

enter image description here

Here is the intended design for that corner. Please note how the window frame is flush with the existing drywall so adding furring strips will push the drywall into the window enter image description here

  • use glue ......
    – jsotola
    Commented Oct 4, 2021 at 2:55
  • 2
    If you're now trying to fix the bad work, wouldn't it make sense to start over on this wall? Remove all the drywall, chip off whatever that yellow stuff is on the left side of the picture, fir everything out (possibly removing the existing firring, if necessary) to a nice new, plumb, flat surface, drywall. Sit back and enjoy the fact that you've done it right and generations after you will appreciate the effort.
    – FreeMan
    Commented Oct 4, 2021 at 13:17
  • I think it would be an overkill. The initial approach, to add the plywood strips was reasonable, this is an all internal wall no humidity there or temperature differences between the two sides of the wall so I do not see why I would take the classical approach with furring everything and then put insulation and drywall. I think that it is better not to have an airgap between the drywall and the wall (if I do not put insulation there).
    – MiniMe
    Commented Oct 4, 2021 at 14:52
  • 2
    @MiniMe Do you want to do it right, or do it quickly/cheaply? Freeman's suggestion (doing it right) is only overkill if your goal is the latter... note that a quick/cheap patch job may satisfy you now, but will cause problems again in 10 or 20 years, when the next person comes through (which may be you again).
    – TylerH
    Commented Oct 4, 2021 at 16:08
  • Also, why do you need/want drywall on a CMU wall anyway?
    – TylerH
    Commented Oct 4, 2021 at 16:09

7 Answers 7


To just answer your question and not debate whether it's the right way or not, use 3/16" x 1-1/4" flat-head Tapcons. You'll need a 5/32" masonry drill bit. Use a regular Phillips screwdriver to screw them into the block and sink them just below the surface of the drywall like you'd do a regular drywall screw.

  • Yes I could do that but preliminary searched just before posting the question here showed me show differences that would make the tapcons more difficult and less recommended to be used for this task. I think the head is bigger for a flathead tapcon andthat might crush the drywall
    – MiniMe
    Commented Oct 4, 2021 at 4:36
  • @MiniMe the flat-head tapcon heads are less than 1/16" larger than regular drywall screws so crushing drywall won't be a problem.
    – JACK
    Commented Oct 4, 2021 at 12:34
  • From past experience with Tapcons I would think that it would be difficult to get the fine level of depth control one needs when hanging drywall. The difference between a proud screw head and the paper tearing is very minimal. I might be wrong, though.
    – Eli Iser
    Commented Oct 4, 2021 at 13:12
  • 2
    @EliIser That's why I recommended using a regular screwdriver instead of a powered one.
    – JACK
    Commented Oct 4, 2021 at 13:42
  • The effort it would take to hand-drive a wall of fasteners into brick suggests it would be a much better trade-off to get to a bare wall and install furring strips the way the gods intended. If you are serious you probably ought to recommend they use low-carbon, phospate covered tapcons, if such a thing exists. I certainly don't know what mudding compound and how it holds room moisture will interact with the usual tapcons out there.
    – user101382
    Commented Oct 4, 2021 at 17:22

Frame the walls first

In most basements I've seen (not sure this is a basement but the same principles apply), you put framing up like any other room. This allows you to set straight studs up (doesn't matter how non-plumb your walls are) AND allows adequate room for things like electrical wiring.

  • All the electrical is in the other walls, there is nothing needed there on that wall. Yes it is a basement bathroom the this wall is the most distant wall from any source of water it has been like this for a very long time and I see no signs of humidity mold etc etc
    – MiniMe
    Commented Oct 4, 2021 at 14:55
  • I also just realized I can't do what you said because there is a window frame there that is flush with the existing drywall on the wall being discussed here. If I add furring strips the drywall will obstruct the window partially (1")
    – MiniMe
    Commented Oct 4, 2021 at 16:57
  • Whether with furring strips or framing, basements windows are almost always reframed to suit anyway. Just because there is an existing frame shouldn't drive the overall wall construction. Basically, you end up "furring" or framing the interior of the window opening, and part of the finish work is to box the window in to its new dimensions.
    – user101382
    Commented Oct 4, 2021 at 17:24
  • Why would I lose window space and room space just to comply with a standard that does not seem to be applicable here and when the old wall was doing fine (no mold no humidity) ?? All looked good excepting the fact that they did not install the drywall parallel with the wall and use wet shimming to correct their own mistake (used thinner wood strips or plywood then it was necessary) I just did not know how to put the drywall back after fixing the issue that led me here
    – MiniMe
    Commented Oct 4, 2021 at 19:08
  • He's asking for solution when space is too tight to frame. This kind of defeats that point.
    – DMoore
    Commented Oct 4, 2021 at 21:32

Drywall is installed on wooden framing, or on furring strips which are attached to the masonry wall. It's a good idea to put a moisture resistant barrier or coating over the masonry before installing the furring strips.

It is critical that the mounting surface be perfectly flat.

  • Yes thank you, I knew about that way but I do not plan to do it like that. You replied while I was editing the question, please have a look again at the added details and change your answer if you feel too Adding furring strips there is out of question right now, as indicated it is an interior wall and partially finished. As you can see in the picture no mold no humidity there
    – MiniMe
    Commented Oct 3, 2021 at 19:28

I've had a related situation when finishing my basement - the wall next to the stairs was concrete, and the width of the stairs didn't allow for framing or even furring strips and still keeping the needed 36" of width.

After consulting the inspector, I glued 1/4" drywall directly to the concrete. In my particular case the concrete wall was facing the garage (i.e. the ground on the other side of the wall was underneath the garage), and the inspector suggested that due to that insulation or moisture barrier were not required. The basement was completely dry in that area and I had no moisture issues since (about 4 years now). The alternative in my case would have been to smooth the concrete with plaster, so the 1/4" drywall was more of a shortcut.

In your case, if you have the room to spare for some framing, it would definitely be easier to do some basic framing or furring and level/plumb that using shims and then hang the drywall with screws into the wood. Otherwise gluing shims and drywall should be possible.

  • I will probably go down the tapcon route as that allows me to replace the drywall if anything goes wrong. I will also have tiles there in the corner so I think tapcon is a better solution than glue. Yes like you I have stairs adjacent to the garage going into the basement and I think you are correct there is no framing there either because I can see the size of the wall from under the stairs where I have cinder block walls exposed
    – MiniMe
    Commented Oct 5, 2021 at 3:24

You can't. There is no drywall where specifications are for direct exterior concrete framing. Moisture will get trapped between drywall and concrete - even if you live in a desert - and this will be a moldfest within a year.

If you want to go directly on the CMU then you must use concrete board. And you can use thinset to secure the concrete board.

  • this is a basement, it is indoor. I don't understand why you say exterior
    – MiniMe
    Commented Oct 5, 2021 at 3:21
  • @MiniMe - basement walls are exterior walls.
    – DMoore
    Commented Oct 5, 2021 at 3:31
  • it is a traversal internal wall load bearing wall not exposed to ground in any way –
    – MiniMe
    Commented Oct 5, 2021 at 16:13
  • @MiniMe - I gave you your answer for your situation. If you want to put up drywall on top of cement - especially in a bathroom - that is a failure and it will mold. Concrete board was made for this and you can paint or tile it.
    – DMoore
    Commented Oct 5, 2021 at 16:24
  • 1
    The only advantage of the concrete board is that if it gets wet it is not going to be ruined. It does not stop mold or humidity as far as I understand. I will install mold resistant dryawall
    – MiniMe
    Commented Oct 5, 2021 at 18:30

I wouldn't say they cut corners but rather they got very creative to maximize the space.

In the end it just turned out to be a poor job.

Attaching drywall directly to cinderblock is a continuation of the previous workmanship.

Unless you're super tight on space then I would build out a proper wall using studs and it will be perfect.

  • There are some implications that led to that, in the remote corner in that picture there is a toilet and then just above it there is an above grade window. The window frame/jamb is flush to the drywall as it is right now If you install furring strips and you "properly" attach the drywall to it then the drywall will get into the window
    – MiniMe
    Commented Oct 4, 2021 at 16:47
  • @MiniMe So you are no longer worried about the insulation per your previous question? diy.stackexchange.com/q/235480/42053
    – MonkeyZeus
    Commented Oct 4, 2021 at 17:12
  • well that was for the wall under the window, this thread is for the wall perpendicular on that window
    – MiniMe
    Commented Oct 4, 2021 at 17:31

I see you are planning on putting tile on the wall beside the window. Another option instead of attaching drywall directly to the cinderblock wall is to apply a roll on waterproofing/isolating membrane and tile directly on the cinderblock. You could tile to the ceiling and add a transition between the tile and furred out drywall.

  • The cinder blocks near the window have some cement and then some finish on them. Not sure if I need a water proof membrane there, there is absolultely no humidity there. I do plan to install tiles on that surface but as shown in the picture and not up to the ceiling as you indicated. I hope that the tiles will be flush (3/8 thick and I am using an 1/4" throwel as the tiles are 24x24) Not sure if I need a special transition from tiles to drywall in this case
    – MiniMe
    Commented Oct 5, 2021 at 16:16
  • I'm suggesting you don't attach any drywall directly to the cinderblock and instead use tile where you don't have depth for furring strips. So you would need a transition between tile and furred out drywall. The roll on membrane also reduces the chance of the tile cracking.
    – Vredesbyrd
    Commented Oct 6, 2021 at 16:29
  • There is a special cement for that to prevent the cracking, I already have it. I do not plan to extend the tiles more than what is shown in the second picture on that wall
    – MiniMe
    Commented Oct 7, 2021 at 4:53

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