Are tile flange screws necessary for alcove acrylic bathtub

[Nitin]

Hi All,

I'm installing a Signature Hardware sitka bathtub 60x30 in a three wall alcove. The tub is an acrylic bathtub with fiberglass coating, and has 5 foam feets under chipboard attached to tub's bottom. I'll have stringers on the long side and one of the short side of the tub, but they are not for support and will just be touching the underside of tile flange. I need to use shims under the apron to level the tub, the gaps left between the shims under the apron will be filled with floor patch. The bathtub will be set over mortar, and I plan to use a plastic sheet between mortar and plywood subfloor. There are several reviews for this bathtub where cracks at corners are reported.

No where in the manufacturers installation instruction they mention to use screws between the tile flange and wall studs. Can the tub be installed without screws? The mortar bed will not be bonded to subfloor due to the plastic sheet.

Thanks

 

[Weekend Handyman]

What do your instructions say?

 

[Sponsor]

 

[Jeff H Young]

Not required necessarily you can put screws into wood , with screw head sort of wedged against flange without drilling through flange. steel tubs are often done that way , assuming you don't want to drill a hole. I like to install w screws , if your tub sits solid and you don't want the screws at all don't put them

 

[Nitin]

Thank you all for your replies. The instructions don't mention screws. I contacted the manufacturer and they said it's ok to use screws. The tub is now installed with screws drilled into the flange, although I had to resolve a couple of other unrelated issues. During dry fit the tub was perfectly level, but after the mortar bed, I was not able to squish down the mortar completely. Tub is level along the long side, but has a small slope along the shorter side. The tub itself has quite a prominent slope on all four sides at the top also, so I don't expect any drainage issue. The stringers don't touch the tub, but the silicone used on top of the stringers may be touching the tub. So, stringers are there, but aren't doing anything. The mortar bed has quite good coverage under the tub, and I also squished more mortar at the drain end of the tub, pushing from the open ceiling in the first floor. Another issue, I ran into was that the drain was not level and caused an uphill of 0.5 inch to the sanitary tee. I decided to put the tee in between the the drain shoe and the 90 on the overflow end. As mentioned several times in the forum, I installed the drain before gluing rest of the plumbing.

 

[Jeff H Young]

your hook up is totally wrong sorry to say. santee should be vertical

 

[Nitin]

I forgot to mention. I replaced the sanitary tee with the fitting pictured below, with the downward sweep facing the tub drain. Will this work? With this setup there is only half an inch of horizontal flow in the water due the the space of the glued section, before it starts flowing down. May be the overflow will have more restriction compared to the normal setup, but it should still drain on those rare occasions.

 

[Jeff H Young]

water will flow through a straw but hardly preferred or pass code . it looks clean but is wrong

 

[Terry]

We use the overflow to snake a tub drain. There should be a smooth path from the overflow to the trap below.

At least two of these work well.

 

[Nitin]

Thanks for pointing out the mistake, Jeff. I now have a much better understanding of the requirements to use certain fittings for a drain, and also how the snaking ability is restricted with my drain (thanks, Terry!) . Unfortunately, the repair now would require opening up the ceiling again! Initially, I had considered the direct drain, but the p-trap was not reaching it easily, and also it was not readily available in abs nearby. I should have gone for it.