View Full Version : pipe through stud: Snug or loose?
ToolsRMe
03-12-2006, 08:55 AM
I need to run some3/4 pipe through a stud. A 7/8” spade bit cuts a hole that is just about perfect; quite snug.
I’m worried that the hole will be too small if the pipe heats up (domestic hot water) and that I will eventually have a failure.
Should I worry? Should I cut the hole larger? What’s the best way to make sure that the pipe does not rattle if it’s in a hole?
ToolsRMe
03-12-2006, 12:02 PM
Make a larger hole.
OK, dumb question.
What's the best way to make a 7/8" hole bigger?
How much bigger would you recommend?
Gary Swart
03-12-2006, 12:11 PM
Probably the easiest way is to use a jig saw, recip saw, or keyhole saw and just carve it out enough to make room. You could redrill it if you happen to have have a 1" steel bit, but don't try it with a spade bit. For new holes, get a 1" or larger spade bit.
ToolsRMe
03-12-2006, 01:38 PM
Probably the easiest way is to use a jig saw, recip saw, or keyhole saw and just carve it out enough to make room. You could redrill it if you happen to have have a 1" steel bit, but don't try it with a spade bit. For new holes, get a 1" or larger spade bit.
What I did that work well is to use a RotoZip set to a 1/8" depth and ream out enough so that a 1" spade could sit on the larger lip. That provided enough "anti-dance" material so that I could drill down with the 1" spade.
Now that we have that solved, what would have happend if I had let the pipe be snug in the wood? I had spoken to the, uh, expert at Home Depot and he said that he had done a lot of new construction exactly that way.
Gary Swart
03-12-2006, 01:55 PM
You would just lose any play that you might need to fit pieces together. Other than that, I don't think it would actually hurt anything to have the tight fit. Sounds like the Roto Zip worked well for you.
What might have happened would be that you would come back here and say that you hear a "drip" in the wall when the hot water is run, but you do not see any water on the floor.
ToolsRMe
03-13-2006, 03:28 AM
What might have happened would be that you would come back here and say that you hear a "drip" in the wall when the hot water is run, but you do not see any water on the floor.
That's interesting and unexpected.
I'm not sure I understand. Are you saying that there could be an actual leak but that I wouldn't see it but could hear it?
Or are you saying that I would hear something that isn't really there? If this second one, what would cause such a phenomenon?
You might hear a "ticking" sound as the pipe rapidly expands while it heats up. That sound, to the unitiated, sounds like a pipe dripping. It will also make the sound as the pipe reverts to ambient temperature, but since that happens at a much slower rate the sound usually is not loud enough to hear it.
khayes
03-13-2006, 09:25 AM
HJ is right on. We have a copper water pipe running through the ceiling over our downstairs den and when hot water is requested upstairs, it sounds very much like a drip, a hard tap kind of sound. It is the pipe expanding and rubbing against the joist it is drilled through. Once the pipe is fully warmed, the noise stops. I've had a plumber verify this - it's been doing it for 15 years and there has never been evidence of any leaks - we've gotten used to it. So go for a larger hole.