framing conundrum: 2" PVC vent pipe going horizontal through 2x4 studs

amakarevic · 01-15-2008, 07:18 PM

need i explain further ?

this pipe will be venting my basement kitchen sink and i am using 2 instead of 1.5" because that way the fixture is within the vent stack scope (8' horizontal outreach for 2" as opposed to only 5' for 1.5" pipe, which i am not within) and i do not have to use loop or studor vent.

anyway, i am sure many of you have seen this use case scenario many times.

the pipe is coming down from the ceiling between beams and then continuing some horizontal 4 ft to the destination. since i do want to have at least one stud over that distance that goes all the way from the floor to the ceiling, i was thinking that it would be cut off where the pipe passes through, then i would mount some 3.5x3.5 rectangular brace through which the pipe would go, then on top of the brace more 2x4 to reach the ceiling.

am i on the right track or completely off and are such braces available ???

thanks,

- a -

**AtlanticWBConst.** · 01-15-2008, 08:36 PM

Without reading all the details of your post, my first thought would be to sugest that you build a "sleeper wall" or "double wall" that the pipe can pass in between.
(In commercial applications of steel framing, that is what is done when dealing with larger-diameter industrial plumbing lines)

Spike99 · 01-15-2008, 09:59 PM

I've read your post several times and having a hard time trying to visualize this vent pipe and what you are trying to accomplish.

If possible, would appreciate a few digital pictures. Simply take a few pictures, upload them into Photo Bucket (for example), public share that specific photo album and post the URL (in this thread). For example: http://s178.photobucket.com/albums/w...ice%20install/

With lots of pictures, many of us can obtain a visual of this venting pipe.

thanks.

.

amakarevic · 01-15-2008, 10:37 PM

everything is in the design phase now.

imagine two vertical adjacent studs, A and B. then imagine a PVC pipe going from the left side of A all the way to the right side of B and even further HORIZONTALLY. the whole thing would look like the letter H, the horizontal dash being the pipe and the vertical lines being the studs. it is forming an inner wall (b/ween bathroom and kitchen), therefore i cannot situate the pipe behind the studs.

hopefully this does a better job explaining.

thanks,

- a -

nap · 01-15-2008, 11:20 PM

there are stud braces you can apply to the studs to replace the strength removed when boring the hole in the stud.

stud braces

scroll down to look at SB1.5. I think that is what you are talking about.

AllanJ · 01-15-2008, 11:34 PM

Can you sister the studs? Or how about just a 18 inch piece of 2x4 alongside each affected stud (also with a 2 inch hole for the pipe) where the pipe goes through? Attach each to its respective stud with several long screws above and below.

OT: I think it would be quicker to put the picture in as an attachment to your reply. Avoid having to register at another site (such as Photobucket) and log in there and upload it and turn on sharing then having to come back and finish your reply.

**AtlanticWBConst.** · 01-16-2008, 07:06 AM

Quote:

Originally Posted by nap

there are stud braces you can apply to the studs to replace the strength removed when boring the hole in the stud.

stud braces

scroll down to look at SB1.5. I think that is what you are talking about.

Those are great, but I think the concern here is to - not over-cut the structural material of the stud. 2" dia. pipe vs. 3.5" stud. That would flunk the framing inspection.

I could be wrong about what the OP is asking, but I am basing this assumption on the title of their first post: 2" PVC vent pipe going horizontal through 2x4 studs

amakarevic · 01-16-2008, 08:36 AM

i cannot sister because there will be drywall on each side and the pipe is going through the 4 and not the 2 side of the studs.

thanks everyone,

- a -

amakarevic · 01-16-2008, 08:59 AM

hopefully this helps ...

thx,

- a -

amakarevic · 01-16-2008, 10:38 AM

more detail ...

Spike99 · 01-16-2008, 01:01 PM

Now I understand. Thanks for the picture....

Here's a few ideas to explore further:

A - Replace the existing vertical 2x4s with 2x6s (or even 2x8s). Hopefully, its a short wall and not too many 2x4s need to be replaced. Also install a new upper and lower stud wall plates. Drill 2" hole within a few of the 2x6s. Then, run the horizontal PVC pipe within the holes. Being 2x6s (or even 2x8s), there would be more remaining wood material on each of the vertical stud 2" holes. To ensure nails don't poke into this horizontal pipe, also add little steel plates on each side of the studs (where the PVC pipe is).

B - If you aren't into removing the existing wall and replacing with a new 2x6 (or so) stud wall, then add onto the side of the existing 2x4 wall. For example:
- Cut 2" hole into the existing 2x4 wall. Ensure the hole is closer to one side of the 2x4. Install the 2" PVC pipe in its horitzontal stud holes. On the thin wall edge of the 2x4 stud, screw a floor to ceiling 2x4 to it. Flat - against the existing 2x4 stud. Thus, making the wall 1.5" wider. Rip a 2x4 approx 1.7" wider - for widening its upper and lower plates as well. The 2x4 "flat" agaist the existing wall will make it stronger. Especially if 2" PVC pipe only goes horitontally acrsss a few 2x4s. For greater protection, also install steel plates - when a screw might be driven into the horitzontal PVC Pipe.

C - Keep this 2" PVC pipe as close to the cealing as possible. Yes, its existing PVC may need to be cut and re-installed higher. Keep the 2" PVC near the outside of this 2x4 wall. As mention above, create a little bulk comparement around it. Since this wall shape will look different then its other part of the wall, perhaps adding a door chime, speaker or something else to that inner wall will make it looked balanced. In other words, you meant to make that specific "upper part of the wall" look that way.

D - Another idea is to install 2x8s (for horitzontal inner pipe) on the short wall and leave the rest of the wall as 2x4s. Then, install sheveling on the 2x4 wall. Little shelf for some sport trophies or other nick-nak things. Thus, giving the appearace you meant to keep a flat thick wall and a shelving wall - in that specific area.

Hope these ideas help as well....

.

amakarevic · 01-16-2008, 01:22 PM

why is it unwise to use brackets as depicted, if available (even if i had to weld my own) ?

thx,

- a -

kgphoto · 01-16-2008, 08:32 PM

They are not rated for that application. There is a limit to the amount of notching of load bearing studs. You can't exceed it without an engineered solution. Re-rout the pipe, or change the wall thickness.

**AtlanticWBConst.** · 01-16-2008, 09:10 PM

Quote:

Originally Posted by kgphoto

They are not rated for that application. There is a limit to the amount of notching of load bearing studs. You can't exceed it without an engineered solution. Re-rout the pipe, or change the wall thickness.

THANKYOU!

...for highlighting the key issue here...

nap · 01-18-2008, 07:08 PM

Quote:

Originally Posted by AtlanticWBConst.

Those are great, but I think the concern here is to - not over-cut the structural material of the stud. 2" dia. pipe vs. 3.5" stud. That would flunk the framing inspection.

I could be wrong about what the OP is asking, but I am basing this assumption on the title of their first post: 2" PVC vent pipe going horizontal through 2x4 studs

if you get the structural rated brackets, you will be fine. They do come in a structural rated version and one that is not stuctural rated. Just get the correct one.

I have seen this exact thing done and the inspector was very specific as to the brackets to use and once those were installed, all was good to go.

Now, I do not know the rated load for a 2X4. Maybe somebody has that info available. The brackets I linked were rated at 570 lbs. If this is inadequate, additional studs could be installed that would make up for the lesser rating of the bracketed studs. There may be brackets available that have a greater rating as well.