Question on drilling holes for pipe

sunlight33

What type of bits are preferred to drill holes for 3/4'' and 1'' copper pipe? It's all drywall for the interior walls, exterior wall has a layer of plywood.
Also do you use anchor or some sort to support the pipe in those holes?

BillyO

I would probably use a paddle bit or hole saw

Jamie Hall

I use a quality paddle bit -- the sort with a pair of teeth on the edges of the paddle, which cut the paper surface of drywall. You need to cut about a quarter inch larger than the outside diameter of the pipe, and you do need to support the pipe -- otherwise you are just asking for odd noises as the pipe expands and contracts.

Paddle bits work well in ordinary plywood and lumber as well.

For larger holes -- such as might be needed for a faucet or a DWV line, for instance, I use a hole saw.

A word of caution: the above comments are for drywall and plywood and ordinary modern lumber. If you ever encounter plaster on lathe, you are going to need a hole saw -- and be gentle. If you encounter older lumber -- say pre World War II -- never mind hardwood framing (it does exist!) -- you will need the best quality bits you can afford -- and expect to use them up (I learned that putting holes for wiring through some chestnut joists on a project...)

mattmia2

An auger bit will work better in hardwood or old dense and dry softwood.

Plaster or drywall will trash the bit, the spade bit can be sharpened and will cut well in wood again, the hole saw will be a bit more durable but would require a professional to sharpen if it even can be sharpened. Sometimes I will drill through the drywall or plaster with a masonry bit then switch to a wood bit to avoid dulling it.

EBEBRATT-Ed

@Jamie Hall

Chestnut? That must be like drilling steel. I have run into that in old houses trying to staple romex. Bent staples don't work so well. Ended up with the wire tys with the mounting holes in them and drywall screws

STEVEusaPA

If you're going interior thru exterior, I'd use a long pilot bit to go straight thru. Then drill each end. I'm not really interested in poking a paddle bit thru insulation.

hot_rod

good point @STEVEusaPA about drilling from two directions.

A holesaw would be the cleanest, although it will not be much good after a dozen or so holes
How will you support the tube? Will it connect to something on both sides?

JUGHNE

I use an 1/4" x 18" pilot bit to go thru both walls.
I use a speed square placed on the wall and bit, on 2 planes to start the second hole, this insures that your bit is perpendicular to the wall.
Drill thru insulation with the drill in reverse to keep from forming a cotton candy ball.
Then complete with hole saw, again drill backwards for sheetrock to avoid tearing up the paper. (The hole saw lasts longer drilling backwards thru sheetrock, gives a cleaner cut than any other bit. )
I usually would sleeve the copper with PVC, this lets the copper move without noise.
So I use a hole saw to match the sleeve.
FWIW

sunlight33

I will use milford hanger to support the pipe to the ceiling stud.

sunlight33

Is milford hanger the easiest/quickest way to support pipes hanging about 6 inches off the ceiling?