Mrs. Dan's Master Bathroom Remodel

[ss3964spd]

Well she's finally had it. Won't let me do any other projects until the MBR is remodeled. And she's right to put her foot down - the MBR is way, WAY over due.

I capitulated, but still retained some manliness by requiring her participation in the demo phase, so 3 weeks ago we got after it. Managed to demo everything in one day except the subfloor and the ceiling.

I already knew I had an issue with the floor. The room is 14'X7' ish and there is a sizable hump running width of the 7' dimension, right across where I thought the 2X10 joists went over the steel support beam spanning the garage below. I cut out the 5/8" subfloor along the bottom plates, pulled it up, and confirmed my guess.

[ss3964spd]

I ran a tight string from both 7' ends of the room, using nails tacked into the bottom of the remaining subfloor under the bottom plates. Where the joists overlap, right over the beam below, is the high spot on all 5 joist sets. The worst of which is crowned by about 7/8".

[ss3964spd]

I decided that I could not raise each end because that will make the finished floor much too high. So I spent a day laying out my strings and shaving down the crown with an electric planner and belt sander. Once finished I laid my 6' level across in multiple spots - it is really, really close to flat. But not level. I now also need to sister the joists.

Which brings me to an actual question: 2X material or 3/4" ply for the sisters? Seems the 3/4" ply would be the way to go; flat, straight, strong, and easier to work with.

Many thanks....

[cx]

Originally Posted by Dan

Seems the 3/4" ply would be the way to go; flat, straight, strong, and easier to work with.

You forgot to mention, "and ineffective," Dan.

If you're sistering to reduce deflection, you'll want to use the 2x material. If you'll evaluate your nominal 3/4" plywood, considering a 5-ply material, you'll see that you'd be adding only about 3/8ths" of material in the correct orientation. The remainder will provide only filler material.

If you want more strength and rigidity, I'd recommend you sister with 2x material, properly installed with adhesive and mechanical fasteners. Or, if you can support each end of the sisters, you could just add new joists midway between the existing to reduce the between-joist spans.

You'll also want to be sure the overlapping ends of your joists at the center support are well fastened together to reduce the cantilever effect of loading near the center of each joist span.

My opinion; worth price charged.

[ss3964spd]

Ineffective certainly wasn't a consideration. My logic - such as it was, was that plywood provides the rigidity for the now nearly ubiquitous I joists. Maybe it's the orientation of that ply used in I joists that I'm missing.

Thanks for the logic-check CX, always appreciated. Cannot support both ends so I'll have to sister them instead of just adding between. I did already suss out the need to bolt together the over lapping joists for the reason you mentioned.

[wwhitney]

Originally Posted by Dan

plywood provides the rigidity for the now nearly ubiquitous I joists. Maybe it's the orientation of that ply used in I joists that I'm missing.

The rigidity of an I joist is provided by the top and bottom flanges, which handle the tension and compression forces resulting from bending. The plywood web's job is to provide the vertical separation between the flanges and to handle the shear forces.

Cheers, Wayne

[Carbidetooth]

Dan, one other thing of note on your first photo. If those copper water lines are contacting the galvanized duct work, you'll wanna separate them to prevent galvanic corrosion caused by dissimilar metals. Might be a moot point if reconfiguring plumbing.

[ss3964spd]

I'm having trouble with that Wayne. Seems to me that a, say, 14' flange by itself would be pretty...bendy in any direction. Isn't the web what carries the static and live load(s)?

Thanks Peter, I did see that when I pulled up the floor. I found no end of wrong under that plywood. I really hate hack work. Vast majority of the plumbing will be re-done so I've already cut out a good deal of the copper.

Thanks....

[cx]

Originally Posted by Dan

I'm having trouble with that Wayne. Seems to me that a, say, 14' flange by itself would be pretty...bendy in any direction. Isn't the web what carries the static and live load(s)?

Nope. As Wayne points out, it's the top and bottom chords that provide the rigidity, the web just holds them in position vertically.

If you'll view the cutting and boring charts for those OSB web engineered joists, you'll note that they're pretty liberal in allowing for rather large holes in the webbing.

My opinion; worth price charged.

[ss3964spd]

Work continues, albeit at a dreadfully slow pace.
Majority of old plumbing has been removed, joists have been planned and sanded down to remove the ginormous crown shown above. Joists have been bolted together where they overlap, and I'm finishing up moving the hvac duct from one joist bay to another (approximately zero fun, that) to make room for the toilet waste line to run to the other end of the room. A basic floor plan has also been developed (which I will post here asap).

The plan has the shower on one of the 7' walls, roughly a 40" X 7' shower. It shall be curbless. The wall separating the shower area from the rest of the room will be a combination of knee wall and glass; 2' of KW and 3' of glass, leaving 2' open, which will be the entrance to the shower. Shower head(s) will be at the end opposite the entrance. Natch.

Which leads me to an actual question: Should/must the entire 40"X7' of the shower area be sloped shower pan, or can I get away with just 5' of it sloped, with the remaining 2' flat - but water proofed?

[Carbidetooth]

To best evaluate, a drawing would be helpful, but my gut says you'd want to slope the whole thing. Assuming that the flat area is a "staging" area, it will certainly see dripping water from wet bodies at the least. I suppose one could put a bathmat there, but otherwise water will stand until it evaporates, leaving mineral deposits.

[ss3964spd]

Thanks for the feedback Peter.

Yes, I envision that end of the shower will be a staging/toweling area. But as such, and given the walk from the sloped area, I don't see much water being deposited on that flat area, or enough water getting deposited on it to actually run back to the drain if it were sloped.

[ss3964spd]

Had a productive 1.5 hour meeting with the bathroom designer. Among many other details we discussed the shower pan. As Peter suggested, she agrees with having the pan run the entire 7' feet.

She also presented a very nice herringbone tile sample. Affixed to a mesh backing each tile measures 1 3/8" X 5". Her thought is to use this tile to cover the entire floor, including the pan.

Curbless pan (foam tray) will be approx. 40"W X 84"L, have a 1" thickness at each of the 4 sides, and with the drain centered. Would this tile be a challenge in this pan, especially given the short but steep slope on the 20" sides?

[Carbidetooth]

My recommendation to clients is no larger than 2x2 tile for a non-linear drain pan. Larger than that and the drainage is somewhat slowed because the pan becomes a series of planes as opposed to more bowl-like shape.

You could address by increasing slope but that, in you case, seems controlled by floor height outside shower.

Looks like lovely tile, but a linear drain would probably function and look better. It that a consideration?

[ss3964spd]

Afraid a LD isn't in the cards Peter. The layout just doesn't lend itself to it.

I voiced my skepticism to the designer about the herringbone laying properly in a center drain pan. She claims she's done - ok, had it done before and it wasn't a problem. She seems pretty much on the ball with details, but at my insistence she agreed that a 2X2 would be easier.

I loved the seamless look but I don't see how that tile will lay nicely in the pan.