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sub floor and joist help!


Jski007's Avatar
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12-11-13, 08:27 AM   #1  
sub floor and joist help!

I'm going to try and attach some pictures to show the situation. I cut out all subflooring down to joists due to water damage around the tub area. I had 1/2" on 1/2". The Joists are 2x8's. The 2" drain running across the floor is already about 1 1/2" to 2" into the joist but sticks above the joist about 1" on the tub side and about 1/2" on the toilet side. I don't want to cut into the joist anymore as it's not up to code I'm sure. I'm going to buy lumber tomorrow and just want to know what to buy. I have about 1 3/4" total of height above joist to play with for flooring to match up with carpet in hallway. I'd like to go less if I can. I imagine I will need to stiffen up the joists due to me cutting in them too far. 2x4 lengths of 2' sistered to the joists where the notches are. Also put them perpendicular in between the joists so I can build my wall for the front skirt of the drop in tub. My guess on this is to go with 3/4" outdoor ply as first layer. Cut it along the 2" drain pipe. The tub will be a drop in so there will be a skirt wall built in front of the tub. With the 3/4" ply that should clear the drain pipe enough to get me to the tub wall I'm going to build. Then do a solid 1/2" ply on top of the 3/4". Would this be the right way and safe way? Also, when I cut the last ply subfloor it continued under the 2x4 framing to the next room. If I do 3/4" as the first layer of subfloor it will rise above the 2x4 and but up against the side of it. Is that ok? Any help on this greatly appreciated and anything thing I might be wrong on let me know. Thanks!!

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Jski007's Avatar
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12-11-13, 08:30 AM   #2  
actually the original subfloor was 5/8" on 1/2" sorry!

 
czizzi's Avatar
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12-11-13, 04:44 PM   #3  
I don't like how you did the plumbing and others will comment on the set up you have next to the toilet flange. But running the tub drain at a 45 degree angle and cutting the 2x8's as you have now basically has rendered them no stronger than a 2x6. You would be better off to do the following. Sister 100% of all the floor joists to regain some strength. Run the tub plumbing in a parallel joist bay until you get near a bearing wall and then turn the drain 90 degrees and run through the center of the joist. Then go parallel again to your final destination. I'm sure we will get others to chime in with further direction so hold tight on purchasing materials until we can correct your situation.

 
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12-11-13, 04:54 PM   #4  
I will look at the plumbing after I straighten the pics... My neck hurts...


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12-11-13, 06:45 PM   #5  
sorry about the pics, don't know why they came out sideways. The drain running across was already there and notched out some in the joints. I just notched about 3/4" more to fit the 2" drain from the 1 1/2" corroded copper one that was already there. The plumber who did the house had to have done that. 2 of the joists are also very close together. there are a total of 5 joists showing, the one on far right under tub has no notch (but has water stain as you can see, not rotted though), the next one 16" away has a 2" notch, the next 2 are 8" apart with a notch and the final one is 16" apart. It's going to be very hard for me to sister in between those 8" apart joists. My guess is they put the 2 close ones together because of the notches? Or the weight of the cast iron tub that was there. The plumbing by the toilet was tricky and about the only option I could go. It was the only way I could have enough slope. Cutting into the middle like you said would be to much out of the 2x8?, especially having to slope it. And I can't run a joist all the way to the center load bearing wall, it's finished on both sides.

 
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12-11-13, 08:37 PM   #6  
No all wrong.... Cant use rubber couplings/ell you have.

Whats the other pipe attached to the toilet ell? From sink?

Is the sink vented?

Tub only needs 1 1/2 pipe...Why did you run 2"

You need to attach the tub to the sink arm in the floor... Cant tie into that tee...


What a mess... I will help you if your going to fix it...

Dont cut/knotch any more wood......!!!!!!!!!!


Mike NJ




"The problems that exist in the world today cannot be solved by the level of thinking that created them".


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12-12-13, 04:50 AM   #7  
I took off the steel 3" that went into the cast iron pipe of the main line down the house. I used a 3" rubber coupling to tie into the cast iron/steel lip that was there. The other pipe is a 1 1/2" from the double vanity going into the 3" toilet L. It's about a 6ft run and I read that is up to code not needing a vent, unless I read wrong. I went with 2" drain from tub to have better drainage. Plus if I ever changed to an upright shower only I know you need 2" at that point right? Just wanted to be ready if I ever did that not having to tear up the whole floor again. The extended rubber 90 is the only thing that worked, I tried all pvc bends but I could not get the cornering right, nothing else worked. It's greater than a 90 degree turn because the 2" pvc sits higher than the 3" T. I would love any help you have thank you!! I'm definitely not notching anymore

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NJ

12-12-13, 07:00 AM   #8  
I read that is up to code not needing a vent, unless I read wrong.
You need a vent.

This is what you need to do...

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You could do it your way but you will need to vent the tub also...

That rubber ell is not allowed. The coupling for the toiler needs to be a shielded no hub coupling...


Mike NJ




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12-13-13, 05:52 AM   #9  
Glad Mike was able to point you in the right direction on your drainage connections. My concerns are with the floor system, your notching and the possibility of driving nails through the drain pipe that now sits directly beneath your subflooring. The code book I have for holes drilled in joists says that you need a minimum of 2" of good wood on either side of the hole. You should be able to get this if you drill dead center. That will also help you set up your trap on the tub without having to stilt the tub up off the floor to make your connections. Here is what I was thinking overlayed on top of Mike's fine drawing.

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Where the horizontal leg through the joists are decided based on proximity to the nearest support wall. Mike can advise if the added run length creates further venting problems.

Again, my concern is the notches, proximity of the pipe, ease of installation of trap, sister joists to regain strength. You already have to abandon the notch you have to redirect the drain toward the sink drain.

 
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12-17-13, 06:04 PM   #10  
Okay it looks like the vent pipe you're showing is between the two vanity drains And is going up vertically meaning out through the roof because this bathroom is a second-floor bathroom. This could be very difficult is there any other way to vent the vanity?

Now the other issue is making that bend having the tub drain come out into the vanity drain it's very tight There I don't think I can make that cornering. Is the 3 inch rubber coupling going to the cast-iron okay? Also if I got a 3 inch 90 for the toilet with a 2 inch tail piece could I tap into that with the drain from the tub? Then tie the vanity drain into that. I would really like to keep the drain going across the way it is if possible.

 
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12-17-13, 06:20 PM   #11  
I am not sure how you want to do it... You will need to show a pic... If you dont vent the sink and tie into the sink arm then you will need to vent the tub,,, That means two vents.. One for sink and tub...


Mike NJ




"The problems that exist in the world today cannot be solved by the level of thinking that created them".


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