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creating the depth for a walk in shower over framing

286 Views 18 Replies 4 Participants Last post by  skyking1
We have two walk in showers planned, one up stairs over a flat ceiling area.
The other is over an unfinished basement.
My strategy was to run 2" shorter TJI joists across that pan area and go from 16" OC to 12" if that will cure the span load problems. It would all depend on the manufacturer's engineering of course.
does that sound like a good approach?
Both of these showers are going to be large enough and have a corner drain so there will be no curb whatsoever. I may do an end gutter that slopes to a corner drain. They will be custom mud pans.
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· retired framer
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Good plan, if the span doesn't work for the smaller one you can try LVLs for the shorter joists.
We have done both and when we get TJIs, the supplier does the engineering and sends a plan with the order just like a truss plan. They just get a copy of the house plan with the information about where the lower shower is needed.
 

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Discussion Starter · #4 ·
I'll get more than 2" out of it due to thinner subfloor, and I can flush block in a piece at the drain corner too. I can go with thinner due to 12" OC with the 3.5" crown, the sheeting span is 8.5".
 

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Discussion Starter · #5 ·
I have found some linear drain systems from Kerdi that I can do with one of their pans. I really liked that route as it was fast and easy.
I think I'll need to drop the whole bathroom floor a bit to allow for thickness difference from the LVP to the bathroom tile, or live with a little threshold bump into the bathroom.
 

· retired framer
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I have found some linear drain systems from Kerdi that I can do with one of their pans. I really liked that route as it was fast and easy.
I think I'll need to drop the whole bathroom floor a bit to allow for thickness difference from the LVP to the bathroom tile, or live with a little threshold bump into the bathroom.
You could frame it in like a hole in the floor with LVLs and the joist would be just to fit the shower so 2x8s would likely do.
Rectangle Door Wood Wood stain Parallel
 

· Naildriver
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It will depend on tile, thinset, slope, liner, preslope. All will be necessary. My estimate would be no less than 3 1/2" total to subfloor.

Now a Kerdi pan may do the job in 2" plus thinset and tile. I believe @jeffnc can chime in on that.
 

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It will depend on tile, thinset, slope, liner, preslope. All will be necessary. My estimate would be no less than 3 1/2" total to subfloor.

Now a Kerdi pan may do the job in 2" plus thinset and tile. I believe @jeffnc can chime in on that.
We did one with shorter joist but then we had to build the rest of the floor up so just the shower was low. I think it was 2" deep but never saw it finished.
 

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Discussion Starter · #10 · (Edited)
I have the TJI TrusJoist specifier's guide open, and the 9 1/2" x 2 5/16" joists will span my requirements with L/480 deflection on the longest spans at 12 OC.
I can use the 11 7/8" elsewhere in the upstairs to create the bathroom well. I think the kerdi pan and linear drain will be the way to go.
I would have to strip block on top of the bathroom joists outside of the shower to create the needed grade change to the LVP flooring outside.
I could rip some stuff to get it right.
One of the bathroom options is straddling a bearing wall area. I think that will make for some good stiffness. I know that L/480 is a minimum for any larger stone or tile and L/720 is preferable. I also have a nearby wall below that can become a bearing wall without any design difficulty. That would cut all the spans way down.
 

· retired framer
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I have the TJI TrusJoist specifier's guide open, and the 9 1/2" x 2 5/16" joists will span my requirements with L/480 deflection on the longest spans at 12 OC.
I can use the 11 7/8" elsewhere in the upstairs to create the bathroom well. I think the kerdi pan and linear drain will be the way to go.
I would have to strip block on top of the bathroom joists outside of the shower to create the needed grade change to the LVP flooring outside.
I could rip some stuff to get it right.
One of the bathroom options is straddling a bearing wall area. I think that will make for some good stiffness. I know that L/480 is a minimum for any larger stone or tile and L/720 is preferable. I also have a nearby wall below that can become a bearing wall without any design difficulty. That would cut all the spans way down.
Yeah when we did it I just jigged up a skill saw so I could rip strips off a 2x10 with my eyes closed.
 

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Discussion Starter · #12 ·
Can I screw/glue furring strips to the top of a TJI to bring it up to grade and then sheet it, or will that blow the design sheeting requirements? I'd hate to create a dead space by having to sheet it first.
 

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Discussion Starter · #15 ·
The more I look around the less I see a need for tile in the bathroom main area. I think we will look at the LVP in there too. That saves me some work for sure. I only need to knock down the shower and a walkout area.
 

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Discussion Starter · #17 ·
I am thinking two of these end to end to make a 4x8 shower, and shim under the upper one to get the grade right. Schluter Kerdi-Shower-LT/-LTS 48 in. x 48 in. Perimeter Linear Drain Shower Tray KSLT1220S - The Home Depot

That's 2 13/16" plus thinset and tile, to match up to the 8 MM LVP.
Looks like around 3.25" deep well.
Pretty close to @chandler48 s idea anyway.
I have the main bearing wall plus a wall I can bear on that is ~5.5' away. Easy Peasy span for 2x8 under shower. I can tail the TJs on that wall. I wonder if I can pass the TJ across for a little cantilever to narrow up the pan to 4', rather than build up the 2x8's.
 

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I am thinking two of these end to end to make a 4x8 shower, and shim under the upper one to get the grade right. Schluter Kerdi-Shower-LT/-LTS 48 in. x 48 in. Perimeter Linear Drain Shower Tray KSLT1220S - The Home Depot

That's 2 13/16" plus thinset and tile, to match up to the 8 MM LVP.
Looks like around 3.25" deep well.
Pretty close to @chandler48 s idea anyway.
I have the main bearing wall plus a wall I can bear on that is ~5.5' away. Easy Peasy span for 2x8 under shower. I can tail the TJs on that wall. I wonder if I can pass the TJ across for a little cantilever to narrow up the pan to 4', rather than build up the 2x8's.
If you do An LVL on both sides you could turn the 2x8s for the shower
And for the raised area change to to 2x10s and strap the 2x10s with 2x4 so it matches the direction of the TJIs.
 

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Discussion Starter · #19 ·
Got it, thanks Neal. That lets me float the shower out anywhere.
We have been drawing that upper floor and I have an alternate shower rotation to look at.
If I bear the drop floor and joist tails on the wall below, I discussed it with the inspector today and I would need a stub footing. That is not a big deal, just 6' in the basement and a bearing wall down there. It lines up with a good spot to build the equipment room walls.
 
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