At some point a previous owner installed hardwood flooring in my house. Nice. They did not however make a hole for the front entryway heating vent. The duct and duct outlet exists in the crawlspace and now I would like to put the vent there. My floors are hickory and all the other floor vents are "flush mount".

I can easily find the vent location in the floor, by drilling up at the four corners of the duct vent outlet in the crawlspace below. I bought the appropriate sized hickory flush mount vent but now realize that I need to cut an awfully straight line, in order to flush mount this cleanly in the floor.

How do I do this?

So that the vent will look right, the cuts need to be exact, straight and the corners square. There are at least these problems:

1) One cut needs to be close to the wall, within 2 inches. This makes it difficult to get a guide or even a cutting tool in there. I can remove the quarter round kick molding, and the other molding behind that off, for a little more space, but that doesn't make that much extra space. It would be a little problematic to remove the main molding. 2) The corners of the cuts need to be square and not extend into the surrounding floor. Hand cut the corners, maybe?!

Somewhat related: Is it possible to install flush mount floor vents in a laminate wood floor?

  • 1
    This is the kind of cut the high-speed oscillating multitools were invented for -- close-quarters plunge cut at a precise location.
    – keshlam
    Sep 28, 2015 at 18:49
  • An oscillating multitool, or rotary tool might be useful, though through hickory it might be slow going.
    – Tester101
    Sep 28, 2015 at 18:49
  • What they said about the fein style multi tool. Cheap and will improve your life if you're doing much diy. Cut a tiny bit off your line, then finish with first a knife, then a chisel. Sep 29, 2015 at 2:01
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    The multitool is the way to go, I would put it in the answer box but you got it @keshlam. @ the OP, I would not sweat cutting in the subfloor too much a little cut into it Is no big deal, it should be easy to gauge how deep you go. A little score into the subfloor is nothing.
    – Jack
    Sep 29, 2015 at 7:56

2 Answers 2


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As Keshlam commented (hence this answer is community wiki), An oscillating multitool is a good choice. You can probably rent one if you don't want to buy one. I would practice on some scrap wood.

  • Kind of depends which way the floor goes. OP might be able to simply take off a couple of boards and cut them with a table saw.
    – gbronner
    Sep 29, 2015 at 14:05
  • Also, when using the oscillating multitool saw, it can be hard to hold it vertically; I find that the saw tends to rotate on its long axis as the cut gets deeper. Putting a book under the 'head' of the tool and using that to gradually cut the wood helps avoid this.
    – gbronner
    Sep 29, 2015 at 14:45
  • This sounds good. Do you do this freehand or with a fence guide of some kind?
    – DavidC
    Sep 29, 2015 at 15:11

Provided there's enough space around your cut, you can use a router guided by a guiding lathe fixed to the floor by some adhesive tape. Select a +/- 3mm cutter, adjust the router depth to the thickness of the wooden floor and move it at the inside of your rectangle. Finally work out sharp corners with a chisel

  • this might be an option but there is not enough room for a router, especially if I use a fence of some kind.
    – DavidC
    Sep 29, 2015 at 15:08

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