Holes for plumbing through floor joists

[jserr68594]

I figured you guys would have the answer. I am needing to drill holes through my all of finished basement floor joists for PEX plumbing. My plumber was planning on putting the holes 2" up from the bottom of the joists.
I am thinking for structure reasons, they should be in the center of the joist. What do you think of my plan? I made a jig to put the holes 4.5" from the bottom edge. Thanks in advance.

 

[mike93lx]

I believe I have seen recommended spacing of at least 3x the hole diameter

 

[nadogail]

Make sure you don't turn your joist into "Swiss Cheese".

 

[finn]

You’re correct. The holes should be near the center, where the neutral axis is. I think there are actually code requirements for how close to the bottom cord the holes can be. I’m no code guru, though.

 

[firebirdparts]

Center is "best" and that's why it's so nice to build for yourself.

 

[rlitman]

Make a jig and keep all the holes in a STRAIGHT line from each other. Use a laser line to assist. If your PEX ends up zig zagging, it gets increasingly difficult to pull through multiple joists due to friction.

2" from the bottom is fine, but centered is better.

 

[Hohn]

Centered and as small as you can make them. The better you line them up, the smaller they can be.

 

[mike93lx]

Pex moves a lot with hot water going through it. Don't go too tight or you'll get squeaking

 

[LOW1]

Pex moves a lot with hot water going through it. Don't go too tight or you'll get squeaking

Or a hole caused by abrasion. I found this out the hard way. It only took about 6 months.

 

[mike93lx]

Or a hole caused by abrasion. I found this out the hard way. It only took about 6 months.

Yeah, I guess a leak is a little worse than a squeak

 

[NUTTSGT]

5 holes dead center, that close ? I might worry about the joist wanting to split over time.

I think I might stagger the holes, 3/4" line above and below the center line you have. Outside and center hole, on top line, inside two holes on the bottom line.

 

[DGersic]

I figured you guys would have the answer. I am needing to drill holes through my all of finished basement floor joists for PEX plumbing. My plumber was planning on putting the holes 2" up from the bottom of the joists.
I am thinking for structure reasons, they should be in the center of the joist. What do you think of my plan? I made a jig to put the holes 4.5" from the bottom edge. Thanks in advance.

Code says minimum distance to edge is (IIRC), 2”. You don’t have to go with the minimum. IMHO, you should move them up to more or less centre of the joist.

Mine:



But (also IMHO) you should be drilling them large enough for the mounting clips, not just the PEX.



Because PEX moves, especially the hot side, and the clips protect it from abrasion.

The reason for the 2” minimum is that the further up you want the holes, the more difficult it is to get in there with a drill, unless you have or rent a 90* drill like a Hole Hog. I did mine with a shortened Irwin auger bit and a collection of extensions to reach through places where the joist spacing is less than 16” on centre.

You’ll find more in my PEX re-pipe thread.

Post in thread 'Plumbing Project - Re-Pipe the House'
https://www.garagejournal.com/forum/threads/plumbing-project-re-pipe-the-house.509833/post-9962601

 

[DGersic]

Make a jig and keep all the holes in a STRAIGHT line from each other. Use a laser line to assist. If your PEX ends up zig zagging, it gets increasingly difficult to pull through multiple joists due to friction.

2" from the bottom is fine, but centered is better.

Good point. A laser would be nice. I marked and drilled mine with two squares. One was set for depth from the bottle, the other was set for distance from the edge. My run is along the foundation edge, making measuring easy. If I was further away, I’d either make a jig, or a string line, something like that to get them consistent.

Keep it as straight as possible.

 

[NUTTSGT]

Job security vs wire nuts and box covers.


I'm torn.

 

[Snapped-off]

Code says minimum distance to edge is (IIRC), 2”. You don’t have to go with the minimum. IMHO, you should move them up to more or less centre of the joist.

Mine:



But (also IMHO) you should be drilling them large enough for the mounting clips, not just the PEX.



Because PEX moves, especially the hot side, and the clips protect it from abrasion.

The reason for the 2” minimum is that the further up you want the holes, the more difficult it is to get in there with a drill, unless you have or rent a 90* drill like a Hole Hog. I did mine with a shortened Irwin auger bit and a collection of extensions to reach through places where the joist spacing is less than 16” on centre.

You’ll find more in my PEX re-pipe thread.

Post in thread 'Plumbing Project - Re-Pipe the House'
https://www.garagejournal.com/forum/threads/plumbing-project-re-pipe-the-house.509833/post-9962601

Is the 2nd hot line a recirc line?

 

[Zeke]

First time this plumber has drilled holes or he doesn't have the correct drill motor?

 

[DGersic]

Is the 2nd hot line a recirc line?

yes

 

[DGersic]

Job security vs wire nuts and box covers.


I'm torn.

The Romex shown was dead, not connected to anything on the other end, and has been removed. The wiring in the box is also dead, but is in inaccessible conduit. It has been capped with wire nuts, and the box covered.

 

[mark198]

jserr68594, this question looks familiar. I would trust these answers a lot more than the boating guys

Mark

 

[pcmeiners]

"The reason for the 2” minimum is that the further up you want the holes, the more difficult it is to get in there with a drill, unless you have or rent a 90* drill like a Hole Hog."

The reason is nails and screws do not usually penetrate more than 2"

Notch beams only if no other method can be used.

 

[Hank11]

First time this plumber has drilled holes or he doesn't have the correct drill motor?

Carpentry for some plumbers involves a sawzall, sledge hammer and a pry bar.

One of my favorite repairs was where they had removed about four feet of a floor joist to plumb a toilet. No heading off, just cut off and hanging in the air. Toilet set on sub floor spanning 32” by 48” without support. Of course the seal leaked but took a few years to get really rotted and wobbly.

 

[mrpizza]

Job security vs wire nuts and box covers.


I'm torn.

I live in a "homeowner special" (see my threads about the basement) and I am rewiring the whole house. I just found last weekend that when they remodeled the kitchen and ran all new circuits, they cut off and left the old circuits in the walls. Cut off and still live via a circuit for a bathroom... 6 different runs in the walls, all live, not capped off.

All of the water supply lines were also drilled in the bottom of the joist, leaving an inch below the holes..... Something else I am fixing along the way!

 

[billconner]

The prevalence of improperly drilled and notched joists not failing sure suggests overbiilding.

fwiw, this is what the IRC requires:

"

R502.8.1 Sawn lumber.​

Notches in solid lumber joists, rafters and beams shall not exceed one-sixth of the depth of the member, shall not be longer than one-third of the depth of the member and shall not be located in the middle one-third of the span. Notches at the ends of the member shall not exceed one-fourth the depth of the member. The tension side of members 4 inches (102 mm) or greater in nominal thickness shall not be notched except at the ends of the members. The diameter of holes bored or cut into members shall not exceed one-third the depth of the member. Holes shall not be closer than 2 inches (51 mm) to the top or bottom of the member, or to any other hole located in the member. Where the member is notched, the hole shall not be closer than 2 inches (51 mm) to the notch."