We've noticed some cut in half floorboards, underneath old carpet looking to see if it is possible to repair these cuts with some way. Or does the entire floorboard need replacing?

We can't put on new carpet until these are fixed, we noticed dents/rips in carpets previously because the flooring bends close to the cuts in the wood.


enter image description here

  • So the boards on either side of the cut are uneven or one side actually has some give to it (not properly supported)?
    – JPhi1618
    Commented Apr 16, 2020 at 16:53
  • yes one side has some give, in the image you can see the bottom half has nails in it that supported, but since there is a cut the top half bends when stepped on.
    – Anicho
    Commented Apr 16, 2020 at 16:56
  • 3
    Look underneath first. Classic place to stash valuables... i.e. why would the floorboards be cut and not fastened/supported properly? That has been pried open, judging by the dents. Hmm...
    – Ecnerwal
    Commented Apr 16, 2020 at 18:19
  • Show us a picture of what's underneath, with one of these boards removed
    – Caius Jard
    Commented Apr 17, 2020 at 7:46
  • 3
    Typical of many houses in the UK, sadly. Electricians and plumbers cut up floorboards to run or upgrade services beneath. Often done poorly and leaving the tongue/groove split, gaps between floorboards and unsupported edges (as shown here). I guess it's "accepted" because it's usually covered with carpet and homeowners don't notice any issue until much later.
    – Carl
    Commented Apr 17, 2020 at 16:54

3 Answers 3


It's normal for floorboards to have cuts in them as getting boards long enough for the entire span is impractical or would be more costly. Shorter boards are commonly used so you will have joints.

However, the joints are normally level and both sides of the board should be supported. A joint should only be made on top of a joist so that both sides are properly supported. In your case it seems like the top half doesn't have the proper support. Perhaps the joint missed the underlying joist and the builder was too lazy to fix it properly or maybe some extra bracing has come loose.

The fix is going to be to remove the board on top and add some bracing underneath it. It should be pretty straightforward to screw a block of bracing to the nearby joist. If the joist is more than 1" away, you may just want to remove the top and bottom board and trim them properly do the joint is centered on the joist or replace the boards if trimming them would make them too short.

  • Thank you for the insight, looks like will cut into board and remove pieces add support or cut up to the supports either side and slot in new piece.
    – Anicho
    Commented Apr 16, 2020 at 17:29
  • @Anicho, no problem, both current answers are similar, I just suggested removing the board because I thought it would be easier to cut that way. If you can get a clean cut with the board in place it may be less work.
    – JPhi1618
    Commented Apr 16, 2020 at 17:30
  • 2
    Also even if the boards were initially a single peice It's very common to cut into floorboards to gain access to the space below when doing plumbing or electrical work. My guess is that is what happened here and someone neglected to add any bracing when they re-fitted the board. Commented Apr 16, 2020 at 18:47
  • @PeterGreen, interesting theory, that would make me feel better than it just being built this way to begin with. In my house, the floors were noticeably "less perfect" in the rooms where carpet was originally installed. In my case, they knew the padding would cover their poor workmanship unfortunately.
    – JPhi1618
    Commented Apr 16, 2020 at 18:58
  • 1
    If there's no joist close enough, you can run a block of wood between the adjacent floorboards and screw all three or four boards into this block from above. Not ideal because it relies on the screws not pulling out but often sufficient as long as you don't overload that one spot.
    – Carl
    Commented Apr 17, 2020 at 16:57

Probably the easiest thing to do here is pop up the board that isn't fastened. Then add additional support below for it. This is just small blocking that you get a couple of nails in. Then just screw the floorboard into it. Whatever is taking the screws for the board right under it can easily support this blocking.

If there is still lipping issues between the two boards a planer or sander is the next step. If you need to do this I would suggest countersinking your screws at least 1/4".


The first thing I would verify is that both of the boards are resting on the joist below. If this is the case, I would try is using some screws to fasten it to it's support tighter than the nails are currently doing. If that doesn't get rid of the uneven surface I'd look into sanding the surface to make the bump smoother, similar to what is done to sidewalks when there is differential movement between two segments.

If only one of the boards is resting on the joist, the only long term fix for this would be to replace the board.

enter image description here

  • Are we saying diagonal screws for the top half, to join it with the supported half? There is no support on the top half.
    – Anicho
    Commented Apr 16, 2020 at 17:02
  • If only one of them is resting on the joist below, cut the lower board back a little to expose half of the width of the joist. Cut the top board at the next joist up enough to leave that joist half exposed as well. Then provide a piece of floor infill between the two.
    – represton
    Commented Apr 16, 2020 at 17:05
  • Whats the best tool to cut from above ?
    – Anicho
    Commented Apr 16, 2020 at 17:07
  • 2
    An oscillating tool would be best for a novice (slow, but easy to use). Trying to make a partial-depth cut with a sawsall (reciprocating saw) is very difficult.
    – JPhi1618
    Commented Apr 16, 2020 at 17:12
  • 3
    A simpler method to support the board is just to screw a small block of wood to the joist, which is what the person who cut the board should have done. Then screw the board down, because nails will work loose and creak. Commented Apr 17, 2020 at 14:05

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