We live on the 4th floor of a pre-war, 1935 apartment building in NYC. On one outer wall, the oak floor is separated horizontally about 1/2" from the wall/baseboard. The floor is also little sunken all over the apartment, but that's not the issue. It looks like floorboard is missing, but its technically not. The wall is flat but must be pulling away. There is even an area where an ancient paper, dry-leaf-like material even sticks out at times! (see 2nd pic) What is that????

We've lived here 7 years with this problem, but i cant tell if it's getting worse or not. I just cant live with it anymore.

The white stuff in the cracks is boric acid i poured in after we started getting a waterbug vistor every night at the same time. The boric acid stopped it, thankfully, but it draws your eye right to the area.

The heater is just to the left of this area, and the floor and wall do get warm in one part. However, the area that has the biggest separation from the wall does not get hot at all, and is always cold to the touch.

I have zero DIY skills, and I dont even know who to call to fix this. Does it need "diagnosing" first? or will any "floor specialist" be able to fix this?

I want to know:

1) What is the world is holding the floor up, because when i shine a flashlight down, there doesnt seem to be anything connecting the floor to the outer wall!

I used to fill this crack with a piece of cardboard because its a perfect color match, but once a piece started falling in ( no subfloor here??), so i pulled it out, except for a piece in the corner.

2) Is this dangerous? Or can i just get something to fill this in?

3) How would i get a filler material like wood ( or cork?) to stay in place if theres nothing beneath it? I dont want to start ripping up my floor because one thing always leads to another in this building! And i'm sure there is lead paint underneath a few layers on my baseboards.

4) Could that ancient papery material sticking out be toxic/dangerous in any way? Anyone know what it is? I think my walls are lathe.

Here are the gruesome pix. Thank you!! the floor

what is sticking out here?

enter image description here

enter image description here

enter image description here

enter image description here

enter image description here

  • 2
    My question is whether the floor is shrinking away from the wall or is the wall bowing out away from the floor. The first case is annoying but probably not a serious problem. The 2nd, however, could be a sign of an impending structural failure. You indicated this is an apartment and by that I assume you mean you are a tenant. In that case you may want to request that the landlord or the management company get someone to take a look.
    – jwh20
    Feb 10, 2020 at 18:14
  • the paper is probably insulation; shredded newspaper soaked with boric acid (in water) as a fire retardant. i doubt it's dangerous, you likely have steel beams supporting the floors where you can't see. You can pull off the bottom trims and replace with something thicker to hide the gap.
    – dandavis
    Feb 10, 2020 at 18:44
  • 1
    it's an apt, but a co-op building, so i essentially own the apt. The superindendent didnt have much insight other than "fill it with matching floorboard". Feb 10, 2020 at 19:30
  • i didnt know boric acid in paper was a fire retardant. It certainly didnt scare away the bugs before i poured it in there! I dont think i can pull off any part of the baseboard ( is that what you mean by trim?). Its been painted over for 80 years and will be a mess. I considered adding a quarter round but i'm afraid it will look ridiculous. also im worried about whats happening there... Feb 10, 2020 at 19:33
  • 1
    When the building needs the brick repointed, or a pipe within a wall bursts, the co-op's main fund pays for it. But if i have to hire someone to rip up my floor to tell me whats happening under there - and its nothing, i dontknow. I honestly just want someone to stcikk a board in there if my floor isnt going to collapse. I just t=dont know how the board will stay up if there is nothing under it in that gap. Feb 10, 2020 at 20:55

2 Answers 2


There are already so many elements to the original baseboards I think adding another one to the bottom, painted white, to cover the gap will look just fine. It will look different to the other walls but only minimally. fill the void with insulation first and lightly pin the new trim to the baseboard, not the floor.

It's a case of you'll know it's there, but it's unlikely anyone else would notice unless they have a particularly keen architectural eye!

My only caveat is to keep an eye on the problem just in case it is the outer wall bowing outwards. Don't forget the floor joists probably run into the wall so it doesn't want to be bowing outwards too much.


It almost looks as though that is not the original baseboard. My guess is that there were, at some point, baseboard radiators/heaters installed there and they were removed and replaced with something else, then they just slapped some plain baseboard where the heaters had been, not caring that it left a gap to the beginning of the flooring. It has been painted dozens of times since so it looks old now, but the way it doesn't really match well with the other moulding is what makes me think it was an afterthought.

  • Thanks, but this is the original baseboard. All of my photos are even of the same wall and baseboard. I can see how it looks different in some pix because of the angle, but the baseboard is the same all over my apt. i WISH this was the issue! . I have the orignal steam heater still intact as well. Thx for the idea though Feb 11, 2020 at 0:58

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.