Joist hole size for plastic pipe

[Flinstone]

Is there a recommended drill hole size when threading 15mm plastic pipe through timber joists? Presumably it shouldn't be too close to allow for expansion but I don't want to go unecessarily oversize either.

Thanks.

 

[Bamber gaspipe]

Is there a recommended drill hole size when threading 15mm plastic pipe through timber joists? Presumably it shouldn't be too close to allow for expansion but I don't want to go unecessarily oversize either.

Thanks.

Been a while since I went to college but I believe you are not to go below one eighth of the overall depth of the joist. Why go thru joists when you can just notch out the top? If you are asking what size hole you should drill to accommodate a 15mm pipe I would should suggest 19 or 22mm.

 

[joe-90]

From an engineering point of view the best place to drill a hole is in the middle. There is zero stress from compression/tension at this point. If you drill an inch hole in a horizontal scaffold pole it will easily support your weight - but if you notch it by an inch - it will collapse.

 

[Blasphemous]

An 18mm should be fine, (depending on your Joist dimensions of course). If you're putting 15mm pipe through you'll need a bit of slack to allow you to push/pull the pipe through into position. If its too tight you could damage the pipe pushing/pulling. So I'd say 18mm.

 

[Softus]

18mm is fine if you want to turn an easy job into a really difficult one.

Otherwise just use a 25mm auger bit.

 

[Bamber gaspipe]

18mm is fine if you want to turn an easy job into a really difficult one.

Otherwise just use a 25mm auger bit.

22.5 spade bit.. just to be contrary..

 

[breezer]

but how are you going to get a spade bit and drill in to drill a level hole ?

 

[Bamber gaspipe]

but how are you going to get a spade bit and drill in to drill a level hole ?

You won`t get a drill anywhere near a joist let alone level unless you are first fixing, it won`t fit, if I had the advantage of talking to people who had a clue I wouldn`t have to explain it.

 

[Softus]

but how are you going to get a spade bit and drill in to drill a level hole ?

That's the whole point - an 18mm hole is nowhere near big enough.

 

[breezer]

gentlemen.

I already knew you cant get a flat bit and drill in between joists, my question was meant to be sarcastic

 

[Softus]

Hm. Good call.

 

[Bamber gaspipe]

but how are you going to get a spade bit and drill in to drill a level hole ?

That's the whole point - an 18mm hole is nowhere near big enough.

Nope , you were too busy rolling your eyes you can`t get an auger bit between joists either matey

 

[Softus]

you can`t get an auger bit between joists either matey

I agree. I never said, or implied, that you can get a level hole with an auger.

 

[Bamber gaspipe]

but how are you going to get a spade bit and drill in to drill a level hole ?

That's the whole point - an 18mm hole is nowhere near big enough.

Can you expand on your whole point? If you don`t mind?

 

[Softus]

No Bamber - I'm not going to entertain another session in which you warp a topic into an opportunity for abuse. Either you understand already, or you never will. That's my last post on this topic, so go ahead and do your worst.