Short version: I want to install one or more pieces of wood that are a total of 3 and 6/8 inches thick (about 2 inches wide and about 2 inches tall). They will be hammered in to a beam behind drywall. They need to be 3 and 6/8 inches thick because I will place a piece of drywall to patch a hole directly on top of the wood, and I want it to be as flush as possible. How can I get a board in exactly these dimensions as easily and cheaply as possible. I see that Home Depot provides boards that are 4 inches along one dimension, so it seems like I could sand or cut off 2/8 an inch. How do people normally do this? If I need to buy a tool that is OK, provided it is pretty general purpose.

Long version: I want to hang a towel holder behind drywall in a bathroom. I have used drywall anchors in the past but they keep falling out b/c people pull on the towel. My latest installation attempt punched a hole in a pipe. A plumber had to cut a hole in the drywall to patch the hole. This revealed a beam. Now I want to hammer in a piece of wood over the beam and then install a drywall patch over it so that the towel holder goes directly into wood, not drywall.

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    Your question is confusing, but the answer seems simple. Rarely does towel bar backing need to be so precise, and I'm not sure why there would be a beam there. What I don't get, though, is how you're doing home improvement with no means whatsoever to cut wood.
    – isherwood
    Aug 28, 2023 at 14:55
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    Bernie may well not be a "him", FYI. Your patriarchy is showing. :)
    – isherwood
    Aug 28, 2023 at 15:36
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    Why is the "Short Version" longer than the "Long Version" ... ?
    – brhans
    Aug 28, 2023 at 19:01
  • @brhans Because the "Short version" is "Here is the information of exactly what I want to do" and the "Long version" is "This is additional information that may or may not be relevant". Aug 28, 2023 at 19:51
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    Also, note that most—if not all—lumber at Home Depot is nominally dimensional, e.g. a 2x4 isn't really 4" wide, it's 3.5" wide.
    – Huesmann
    Aug 29, 2023 at 13:10

1 Answer 1


Just for future reference: Normal practice in the US is to simplify wood size fractions when possible. So 3-6/8" becomes 3-3/4".

Also, most of the time with this type of work you want to use screws - drywall screws for drywall into wood and wood screws for wood into wood (in a pinch drywall screws will work for anything, but they are not ideal except for drywall).

So if you don't already have one, pick up a battery powered drill-driver. 18V-20V is the typical these days. At Home Depot the moderately priced brand is Ryobi - typical is a kit with basic drill/driver and battery and charger currently for ~ $60. Get a pack of drill bits and driver bits (the brand does not need to match the brand of drill - whatever seems like a reasonable price that day). Also pick up a hand saw for cutting wood to size - you do not want to get a circular saw to cut a few occasional small pieces of wood - too dangerous if you don't use it enough to get to know it, and really not necessary.

There are a few ways to deal with this. I 100% agree with "towel bar into wood", but I wouldn't try to use tiny pieces (2" x 2"). Two possible fixes come to mind:

  • Outside

Find the two nearest studs. They are typically 16" apart (on center) though it can vary. Cut a piece of wood, typically 3/4" or 1" thick, long enough and wide enough to reach both studs and to hold the towel bar where you want it. Optionally paint or stain to match the room - easiest is usually just to paint it white. Screw it into the studs. Screw the towel bar into the wood. If the wood covers the existing drywall holes then you don't even need to patch the drywall.

  • Inside

Cut the drywall hole so that it reaches a stud on each side. Cut a piece of wood, typically fairly thick (e.g., a piece of 2x4, which is really 1.5" x 3.5") to fit exactly between the studs. Screw it to the studs (this requires screwing at an angle, so a little trickier than an outside fix). Cut a piece of drywall to fit the open space and screw it into the wood. Patch/paint - how much depends on how nice you want it to look. Install the towel bar, making sure that the screws go into the wood.

You can also cut the existing hole larger, but not all the way to the studs, and use layers to get your 3-3/4" depth. A 2x4 is nominally 1.5" x 3.5", so a piece of 2x4 screwed to the "beam" plus a piece of 1/4" plywood should get you to 3-3/4", though you may need to measure carefully and you might actually need 3/8" plywood. But I would go with either an outside piece of wood (avoid the drywall work!) or inside stud-to-stud (which is the standard way of doing this).

  • Thanks for explaining this. For the inside solution, why does the wood need to fit exactly between the studs? Are you saying that the wood should fit exactly flush between the studs? Also: "Cut a piece of drywall to fit the open space and screw it into the wood." => there will be a gap of a few inches between the back of the 1/2 inch piece of drywall and the wood flush between the studs. So to fit into the open space the drywall would have to be about 3 3/4 inches thick.
    – Bernie2436
    Aug 28, 2023 at 15:47
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    Yes, exactly flush between the studs. Then you screw at an angle from the new wood into the studs. If it is too short then you have a gap which will not hold very securely. And if it is too long then it would have to overlap - which is actually what you do with the outside solution, except then it is outside the drywall as well. Aug 28, 2023 at 15:49

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