Notching and boring

[markcool]

I'm roughing on in my attic, and there are some situations where I can't figure out a way to get pipes where there need to go without violating the code for notching and boring in framing.

My current challenge is with the venting.

I have a first floor fixture group coming up into the attic via a 4" cast stack. I am running the new group, which is 2 stud bays away, with a 3" pvc stack. I want to reduce the 4" to 2", and tie it into the 3" above the flood plain of the highest fixture, connecting horizontally.

This means boring 2" holes through two studs in a partition wall.

My question is, Do people do this, then use stud shoes or something? Or do the plumbers just leave it for the carpenters to figure out later?

My other option would be to reduce the 4" to 3" or 2" pvc, then run straight up through the roof. That would mean compromising the top plate of the wall, which seems the lesser of two evils.

I would rather not have the add'l roof penetration if I don't need to.

I won't even get into my other framing issue, where I cut off the end of joists to get the toilets in. I am anticipating getting an engineer involved, and hoping I don't need an exposed beam below.

The third photo down on this page shows the 4" cast, 2 studs away from the stack I want to tie into horizontally.

The other pics show the cut joists, They used to bear on the top plate of the wall I'm running the drain inside of.

 

[KULTULZ]

IMO- (In My Opinion)

-JOIST BORING GUIDE-

You need to reinforce the floor joists by boxing (use hangers) and doubling joists that have been cut (screw and glue).

If a stud wall, care must be taken if load supporting.

 

[markcool]

Thanks,

I'd like to do that with the joists, but I can't get a full 2 x 6 across to hang on hangers. there are water supply pipes and a 2" drain on that would have to be notched out of the boxing members. This is why I may have to support from below, or get an engineer's report saying that I can use some sort of 3" steel.

Any thoughts on the 2" bores through 2 x 4 studs? Not load bearing. I found stud shoes online made by Simpson. That's what I'm leaning toward.

 

[KULTULZ]

Thanks,

I'd like to do that with the joists, but I can't get a full 2 x 6 across to hang on hangers. there are water supply pipes and a 2" drain on that would have to be notched out of the boxing members. This is why I may have to support from below, or get an engineer's report saying that I can use some sort of 3" steel.

Any thoughts on the 2" bores through 2 x 4 studs? Not load bearing. I found stud shoes online made by Simpson. That's what I'm leaning toward.

You are working with 2" PVC DWV? You can safely bore through the center of a 2 X 4 (3 1/2" W) safely (limited to code) and not compromise the integrity of the stud. If a load bearing wall, you may want to sister the studs where the pipe runs through it. I don't think you would need a stud shoe but would need nail guards.

Same on the boxing cross beams. You want to drill access holes rather than notch as notching weakens the beam.

Can you run the vent through the top plate to join the main vent before the roof line (this being allowed to code)?
The shoe would be used on the top plate.

Now remember I am not a professional but can do simple framing. Listen to the professionals here before proceeding...

One illustration below shows nail plates. The longer one is usually a heavier gauge and that is used to either reinforce or align a bottom and/or top plate that has been cut for plumbing.

I hope this helps and doesn't add to the confusion.

It is safer to have the framing accommodate the plumbing rather than the other way around.

 

[KULTULZ]

ADDENDUM- (French For I Thought of Something Else)

In the illustration below, it shows 1 1/2" and 2" PVC/CI DWV routed through stud spacers on a 2 X 6 water wall. I make the necessary hole in the lumber and then open it completely with a jigsaw. They will receive nail plates and the bottom plate will get the longer nail plate I mentioned.

Maybe this will give you an idea?

 

[phishfood]

If the studs that you are penetrating are not holding up trusses, you can double up the studs. Or, can you reduce the 3" to an 1 1/2" vent and revent that back into the 4"? That way, you will still be within code on the hole size in the studs, and still only have one vent penetration.

Edit: The above is allowed under the International Building Code. If your code is not based on that, ignore what I posted.

 

[markcool]

Thanks.

Where do you find those stud shoes from the photo?

Is that fernco fitting allowed inside a wall? I thought that I would have to use a donut to go from my cast to pvc.

Running the vent thru the top plate would have me going thru 2 rafters to join. I'd kind of rather bore the joists in a partition wall.

The 2 x 6 joists are still my biggest issue. If you look at the link, I cut the joists to allow for the WC's to get to the wye. In 2 places the 2 x 6's no longer bear on the top plate.

Boxing, using joist hangers, glue and screw is no problem for me to figure out. The challenge is that there's no place where I don't also run into 2" pvc drain that would have to be notched out of the 2 x 6 lumber forming the box. This would leave me with 3" of lumber where I would have to notch.

I don't think I'll pass the framing inspection with joists that have a 3" notch out of the bottom. Any other ideas?

 

[KULTULZ]

Where do you find those stud shoes from the photo?

GOOGLE- SIMPSON STUD SHOE

Is that fernco fitting allowed inside a wall? I thought that I would have to use a donut to go from my cast to pvc.

No, it is a CHARLOTTE PIPE PVC to NO-HUB CI transition fitting/coupling. You would use the correct FERNCO coupling.

Running the vent thru the top plate would have me going thru 2 rafters to join. I'd kind of rather bore the joists in a partition wall.

The 2 x 6 joists are still my biggest issue. If you look at the Plumbing rough-in for attic, I cut the joists to allow for the WC's to get to the wye. In 2 places the 2 x 6's no longer bear on the top plate.

Boxing, using joist hangers, glue and screw is no problem for me to figure out. The challenge is that there's no place where I don't also run into 2" pvc drain that would have to be notched out of the 2 x 6 lumber forming the box. This would leave me with 3" of lumber where I would have to notch.

I don't think I'll pass the framing inspection with joists that have a 3" notch out of the bottom. Any other ideas?

You drill access holes for the 2". Notching weakens the joist.

 

[markcool]

Thanks again for the replies.

I have found those simpson shoes, the ones in your other picture looked like a different brand, I was looking to compare.

Regarding the 2x6 joists and notching, the 2" pipes are already in place, so the only way I can see to deal with them is to notch. Even if I was to cut out the pipe, bore the joists, and use a repair coupling, the pipes would be in the bottom 1/3 of the joist, and weaken the same as a notch.

I would like to find a way to avoid installing a beam below, but I may have to open the walls and drop in a double 2x6 , which would give me a bump-out below.

So I have read some, and it looks like I can use the shielded type of fernco for a remodeling situation. I'll try it, it beats taking apart the cast at the hub and wrestling with a donut.

 

[KULTULZ]

Regarding the 2x6 joists and notching, the 2" pipes are already in place, so the only way I can see to deal with them is to notch. Even if I was to cut out the pipe, bore the joists, and use a repair coupling, the pipes would be in the bottom 1/3 of the joist, and weaken the same as a notch.

I would like to find a way to avoid installing a beam below, but I may have to open the walls and drop in a double 2x6 , which would give me a bump-out below.

Maybe...

Extend the fabricated box further to contain the 2" pipe and then add notched spreaders to the now extended opened box section as reinforcement for the sub-floor material?

Either side joist would have to be sistered, glue and screw and of course hangars. When notching the spreaders to accept the 2"pipe, use a hole saw and open the hole to match the drilled hole with a jigsaw? Rough notching weakens.

This would save you the appearance/problem(s) of a support structure below.

 

[Mr_David]

I'm not going to coment on the joist thing. Looks like other have that covered.

Do you need to have a 3" vent coming off the toilet?
I guessing you are adding the toilet ayou only need a 2" vent.
The bigger issue I see is the waste arm from the closet bend should feed into a Santitary tee , not a wye.

 

[Mr_David]

Here are links to a previous comments on wye vs Santitary tee

The combo does NOT work well for a vent because the branch connects to low for the trap arm.
The Vent is to break the siphon on the trap and if it is lower than the bottom of the trap arm it fails.

For the same reason you changed the one at the tub.
Let's say the water draining out takes up about 1/2 to 3/4 of the horizontal trap arm. The air from the vent can not break the siphon of the water flow because it is below the the bottom of the horiztal trap arm. I see if I can find a better example to explain it.

found this

 

[markcool]

Damn!

I took out a tee and put in the wye because of other advice I had on this forum on a thread I posted re back to back toilets: http://www.plumbingforums.com/forum/f2/toilets-can-i-put-2-toilets-back-back-double-tee-2298/

Regarding the framing, here's what I've done:

Instead of notching for the 2: pipe and the H and C 3/4" pex lines, I cut them all.

Next, I made my double 2x6, boring out for the 2" and the 3/4" penetrations. I fastened a stud shoe to this 2x6 assembly, set it on double 2x6 joist hangers, put the pipes through it, and glued and crimped the pipes back together.

On the other side, I was able to drop in a double 2x6. Everywhere that original joists meet my new headers I've put in 2x6 angle brackets.

There's a photo attached.