2

I need to decide which is the best way to cut holes into drywall to run new Romex wire down and across a wall(s) (between studs). There are many ways, but I have narrowed it to three options: cut a square/rectangular hole using a sharp drywall knife, or use a drywall cut-out (or multi) tool, or use a large circular hole saw?

I am leaning towards using a small and a large hole saw attached to my hand drill and reuse the circular blank left over in the hole saw to patch the hole instead of cutting a new drywall patch every time, then afterwards replaster, sand, and paint.

Are there any problems, issues, and/or advise with this approach, or is there a better way (listed or not listed above) that works better?

AL

10
  • 2
    How are you scoring the results that we can determine which is better?
    – Jasen
    Jul 14 at 1:36
  • 1
    Do you have an electrician’s long-length drill bit? Jul 14 at 2:01
  • 8
    Opinion: oscillating tools are great if you aren't too worried about drywall dust. Drywall jab saws are a little less dusty. Hole saws are too precious to grind down on gypsum, given no appreciable benefit to a round hole. Not that you asked, but powered sawzalls are good for finding hidden plumbing and electrical lines. Jul 14 at 3:36
  • 3
    hole saws tend to take a thick circle of material out between the hole and resulting plug, making it harder to patch seamlessly than a square hole where at least 2 sides can align edge to edge. If you have tall enough baseboard, you can go behind that, which makes perfect patching a low priority.
    – dandavis
    Jul 14 at 3:52
  • 2
    Any one of your methods will work just fine. Which one is "best" is determined by how good you are at patching drywall, what tools you have on hand and how good you are at using them. VtC: "Opinion Based". You've currently got 3 different recommendations, all of which are good. What criteria will you use to judge which is "best"? Since you haven't told us, we can't tell you.
    – FreeMan
    Jul 14 at 18:30

4 Answers 4

6

In my opinion, the best option is a fourth option you left out: oscillating tools. Example:

Oscillating tool

If that's what you meant by "drywall cut-out" then great, though I find that is usually used to categorize roto-zip type tools.

These oscillating tools have the following benefits:

  • The cut is thin and pretty clean, so you can reuse the cut piece for easy patching.
  • since you plunge in, you can cut with virtually no risk to cutting cables or piping, which is a major concern using other power tools in this application.
  • A lot less laborious than using a drywall knife.

Their only real downside in my opinion is they make a lot of dust, but that can be well mitigated with a trusty vacuum.

1
  • 4
    they work so effortlessly well that you might want to put a marking band of masking tape around the blade a set distance from the teeth as deep as your drywall is thick, to avoid nicking studs, wires, pipes, etc.
    – dandavis
    Jul 14 at 16:52
2

I think we don't have enough real information to guide you, to be honest. You have to run wires down or up within a stud bay either from the floor above or floor below, and then across the wall horizontally from the chosen bay to the left or right to the device box that you'd like to connect.

If you don't have a flexible auger bit for a drill that allows you to drill through multiple studs horizontally from a single access hole (or you have to drill through exterior studs where there is insulation that would get caught in the auger), then you will need to cut an opening in every stud bay.

Regardless of which size and shape of cutout you choose, whether it be a round hole or a square one, the most important thing is that the centre of the studs forms the edges of the hole. The reason for this is that when you re-attach the drywall, you will need solid structure to provide backing for the drywall.

There are ways of adding backing support to a hole that has no framing behind it, but it will add time and material cost to your work.

So, if you are cutting a rectangle between studs, make sure the sides of the rectangle fall on the stud centers. This means that you will probably hit drywall screws as you are cutting, but that's not a big deal.

If you are cutting a round hole, cut the centre of the hole on the centre of the studs so that you can re-attach the cutout in the centre.

What I have done in the past is cut rectangles that are 16" wide, because the studs are 16" O/C. When I have run new NM cable in interior walls with no insulation, I only need to cut the drywall at the top/bottom of the stud bay to pull the wire into the bay and then a hole at each end of the run. I use a flexible auger bit (48-72" long depending) to drill through the studs without removing excess drywall.

Keep in mind that auger bits will cause you some frustration in some cases. The bits can get dulled easily if you hit a nail, and they might need a fairly powerful drill to make it through older wood.

10
  • If you cut on the stud, how do you get a drill in to drill through the stud, parallell to the wall? Or are you taking out a huge amount of material?
    – Tim
    Jul 14 at 7:14
  • Say I want to get my wire 6 feet across the wall. I have a stud bay that I am going to be feeding the wire up through the bottom plate from the basement. I know my new device box is going to be 14" from the floor. I might cut a 16" x 16" square near that height in my stud bay and bring up the wire from the basement. Use my auger bit to drill through studs to my 6' distance, and a new cutout for my old-work device box. Use a fish tape to pull the wire through the holes in the studs that the auger bit made. Jul 14 at 7:26
  • For support of the round drywall hole plug I will use 1 1/2" x 5/8" piece of wood across the diameter of the hole using drywall screws on each side, and then secure the drywall plug by driving a drywall screw into the center of the plug and into the piece of wood behind the plug. It seems the tricky part is determining right number and placement of the holes, so it doesn't become noticeable after patching and painting. Jul 14 at 7:35
  • 1
    I prefer to put anything deeper than that, for future hole-borer's/nailer's safety.
    – Tim
    Jul 14 at 7:53
  • 1
    @AlwaysLearning Strongly suggest that you get an electrical permit if you're thinking that notching studs is a reasonable idea. You'll want an inspector to help you avoid risking a fire. Jul 14 at 8:16
1

Use a holesaw, large enough to get a right-angled drill and bit in, to one side of the stud. So, not actually centring on the stud, but to one side. That way, the circle removed can be pinned back into place on the stud (and not fall through) making the re-fix easier. Something like a 4-6" saw may do. That's if you have a decent stud finder! But after one hole, you can usually poke something in to find the edge of the next stud.

0

Use a hole saw, then make a butterfly patch out of a piece of scrap drywall. Use the same hole saw to cut through the back, while leaving the front paper intact. Pull the parts of drywall off on the outside of the cut, then trace this square onto the wall. Score the wall with a knife and remove just the paper from the wall. Mud it up and press the patch into the mud. Removing the paper from the existing wall eliminates the need for feathering the mud, and the paper provides strength to resist cracking. I do it all the time.

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