I'm redoing my back landing area and pulled off a piece of trim off the wall and a piece of quarter round off the staircase because I want to sand and paint the wall and don't want random pieces of trim anymore.

Turns out there is nothing behind the trim. Do I need to cut a strip of drywall first or could I fill it in with some sort of plaster? If I need to cut a strip of drywall how would I screw it down then? The wood visible inside this strip of wall is the hardwood in the room next door, I don't really want to screw into there.

Thanks :)

enter image description here

  • The hardwood what? It looks like pine/fir subfloor and a wall plate to me. A standard drywall patch seems appropriate. You'll need to tape both joints.
    – isherwood
    Commented Mar 24, 2017 at 17:14
  • No it's the hardwood from the room next door. Maybe not super visible in the picture but it is. Commented Mar 24, 2017 at 20:51

3 Answers 3


If that's actually subfloor (softwood t&g) and finished floor we see in the photo, you really need to strip back some of the remaining drywall and mount a patch that spans the gap to solid framing. There's almost certainly a wall plate on top of the hardwood (odd, but explainable by past renovations), and a floor joist below.

I'd cut 3/4" from both the top and bottom of your channel to find those, and then install a strip of drywall to them. Tape both joints in a nice wide, tapered manner and you'll have a good result.


Actually what I would do in both situations(hard wood or sub floor) is just cut a strip of drywall to fill in your space but don't cut 3/4" off of any existing drywall. I assume this was suggested so you would have some backing to screw to. But you can glue in your repair piece with some general purpose joint compound( not topping joint compound) this stuff is made with some type of glue and you will have it on hand anyway when you gather you materials for the repair. Use the paper tape also and use the standard repair process a few applications dryed between coats each coat wider than the next. You can even use old credit cards instead of buying taping tools you're only gonna use once. Prime before painting cuz new drywall mud is porous and will absorb your usually more expensive color paint. This is more noticeable when using satin or semigloss finishes because you won't get a shine until the third or fourth coat. Also if it doesn't matter what it looks like you can always just glue in your repair piece a little narrower than the gap and center it in place. Then fill in your top and bottom gaps with paintable white caulking and smooth it with an old credit card. If done right it will look just as good as a conventional drywall repair only with a faster finish time. Good luck.


Use drywall joint compound rather than trying to plug in a strip. It will take several applications of increasing widths. let each layer dry thoroughly and sand between each application (lots of on-line tutorials). Done properly you will not be able to see the repair area.

  • 2
    I'd stress the need for tape here. A channel that wide is almost guaranteed to crack if it's not reinforced.
    – isherwood
    Commented Mar 24, 2017 at 18:39
  • I never sand either. Don't put on too much to begin with and then use a sponge to feather the edges.
    – topshot
    Commented Mar 24, 2017 at 18:43
  • Thanks :) I'm glad, that seems the easier way to go anyway for someone inexperienced with drywall. Commented Mar 24, 2017 at 20:51
  • Please use upvotes rather than "thanks" comments to register your appreciation. Those comments will be removed by the community.
    – isherwood
    Commented Mar 24, 2017 at 20:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.