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 Hole Size for Pipe Passage Through Framing
Author: keithailor (AL)

I'm replumbing a trailer with Rehau PEX. I'll be using 1/2" and 3/4" PEX. How wide of a hole should I drill through the framing. Do you professionals size the hole bigger to allow for possible pipe expansion? For example, I measured the outside diameter of the 3/4" PEX and determined that a 1" hole through the framing would leave maybe 1/16" clearance around the pipe. Is this enough room? There is no reason, that I can determine, to drill a great big hole and then use an entire can of spray foam to try and fill the gap. Thanks, as always!

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 Re: Hole Size for Pipe Passage Through Framing
Author: SMSPlumbing (PA)

You are correct as to have the hole bigger than the pipe for the pipe expansion.

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 Re: Hole Size for Pipe Passage Through Framing
Author: Wheelchair (IL)

Don't forget the protective grommet where the pex comes in contact with the metal of the frame and vibrations.

Best Wishes

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 Re: Hole Size for Pipe Passage Through Framing
Author: keithailor (AL)

where can I purchase these grommets? Are they long enough to go through a (5.5") 2" x 6"?

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 Re: Hole Size for Pipe Passage Through Framing
Author: Wheelchair (IL)

I'm sure there are several manufacturers of this product. Sioux Chief is just one.
Best Wishes

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 Re: Hole Size for Pipe Passage Through Framing
Author: LemonPlumber (FL)

Well the right size holes are very sightly larger a 1/16".Never a 2 "hole for two 3/4 tubes.It is two 1"holes one over the top of the other with the hot line above and both as near the center of the stud as possible!No sleeves on wood passage/ONLY metal.where tubing control needs be placed the top plate and fire blocking could take foam.but any air barrier that dose not harm the tubing like chalking could also be used.Be aware foam o fill may cause thermal clicking.not harmful but audible nuisance.Never get structural foam near a fitting.

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 Re: Hole Size for Pipe Passage Through Framing
Author: Royboysc (SC)

If you use the snap in grommets, they require a 1-1/4" hole but the grommets sure work nicely.

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 Re: Hole Size for Pipe Passage Through Framing
Author: caja715 (Non-US)

and if you are doing drywall after all is ran, and your running the lines through 2x4 strike plates are a nice piece of mind

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 Re: Hole Size for Pipe Passage Through Framing
Author: LemonPlumber (FL)

we call them nail plates and they are code.

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 Re: Hole Size for Pipe Passage Through Framing
Author: hj (AZ)

quote; .It is two 1"holes one over the top of the other with the hot line above

WHY does the hot have to go on top, especially since the tradition, dating back to the days of the "trough wash sink" has been cold on top so you do not get burned by leaning on the piping.

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 Re: Hole Size for Pipe Passage Through Framing
Author: hj (AZ)

They are not only "nice" but required, and we use 1 1/2"x6" ones.

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 Re: Hole Size for Pipe Passage Through Framing
Author: LemonPlumber (FL)

when the tubing is enveloped.the hot when not insulated should not effect cold temp.It can when installed below the cold.here it is humidity question also.but since some area's have low condensation problems guess hot when not exposed should still be on the top!think the very nature or temperature movement would require it.cold low hot high.You already know, I believe any new un- insulated hot line is defective.

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 Re: Hole Size for Pipe Passage Through Framing
Author: mr leak (CA)

Pex makes isolators that are sized for 1/2 and 3/4 pex both sizes are designed to go in a 1 3/8 hole Run the pipe thru the hole then place the isolater around the pipe [they are split so spread easily at point of use ]then tap in place with a hammer Done they isolate and "grip" the pex

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