Replies

1. 
   DanT | Apr 30, 2006 11:18am | #1

   Pre drill a hole at each stud into the flange.  Install a deck screw in each hole.  Before hand make sure it is level in all directions and mix a bag of mortar up fairly dry and pour it under the bottom of the tub.  Push the tub into it , check for level.  Screw away!  DanT

1. 
   PearceServices | Apr 30, 2006 03:47pm | #2

   Another thing.

   some fiberglass tubs still move a little even when installed properly, and you can hear squeeks where the flange meets the studs, a little strip of plastic, or even silicone caulking can reduce the noise. and do not overtighten the screws to try to pull the flange tight, shim if needed.

1. 
   gcrow | May 01, 2006 05:33pm | #10

   thanks for your help.

1. 
   rez | May 01, 2006 07:55pm | #11

   Seeing it would seem that a fiberglass tub will need replacement in future years, might it not be logical to place the setting compound/motar the tub will sit on inside a plastic trashbag or between two sheets of plastic to ease future removal?

   Doing such shouldn't affect curing, would it?

   half of good living is staying out of bad situations

1. 
   PearceServices | May 02, 2006 03:04am | #12

   Kohler does recommend this for some of it's tubs, but for expansion and contraction, they ask for a layer of plastic sheet between the mortar and the plywood floor

2. 
   gcrow | May 01, 2006 05:33pm | #9

   thanks for your help.

3. 
   plumbbill | May 02, 2006 05:07am | #13

   Did someone mention setting a tub?

   Here's one for ya C I jetted weight 520 lbs clearence 3.5" in back 6" left & right.

   View Image

   View ImageDo you look to the government for an entitlement, or to GOD for empowerment. BDW

   
2. 
   Duey | Apr 30, 2006 07:55pm | #3

          I agree with above posts. Mortar underneath, shim if needed, and use screws. The only thing I would do different is to use pan head screws instead of deck screws in those pre-drilled holes. The deck screws, because of the wedge-shape under the head, will sometimes have a tendency to crack the fiberglass around the hole.

         One other thing I do when I install tub/showers, is to shim out above the flange on the top of, and alongside the flange on the sides of the unit, and screw the drywall through these into the studs. You can easily crack the drywall otherwise. On the last few tub/shower units I installed, I made sure I had a stud behind the vertical flange to screw the unit to, and another stud just on the  outside of that and then I ran a strip of 1/4" plywood(width of stud) all the way to the top of the unit and then finished with a long tapered shim to return back to the stud. I use the same principal along the top of the units, except I just use the tapered shims, resting the thick end (which should be the same thickness as the flange and screw heads combined, or slightly less) right on top the unit with the shim going up the stud. The drywall lays on them perfect with no danger of cracking or distorting. The long shims make the slight angle unnoticeable. The drywall should never be screwed through the flange! Good luck!           

                                                                                                 Duey

1. 
   DanT | Apr 30, 2006 08:31pm | #4

   Good point on the pan head screws.  The reason we use deck screws is to avoid rust.  DanT

1. 
   Duey | May 01, 2006 01:49am | #5

         Good point on the rust, but I think you can get galvanized or stainless pan-head also. If the unit is properly installed and caulked, there shouldn't be any moisture getting to the screws to cause rust.

                                                                                             Duey

1. 
   DanT | May 01, 2006 01:52am | #6

    "If the unit is properly installed and caulked, there shouldn't be any moisture getting to the screws to cause rust."

   Oh yeah, the real world where everyone properly maintains the work we have done.  I forgot.  Actually I have never seen it lol.  DanT

1. 
   Duey | May 01, 2006 02:00am | #7

           Excellent point!!!  I stand corrected!

                                                                                                 Duey

2. 
   gcrow | May 01, 2006 05:32pm | #8

   thanks to all of you for your excellent advice.  its been very helpfull.

3. 
   ChipSB | May 15, 2021 01:55pm | #14

   I would not screw/nail the tub flange to the stubs by drilling through the flange. Use a pan head screw or drywall nail and only let the head overlap the flange. This allows some movement without cracking the tub.