Sterling Bath Makes Noise when pressure is applied

Hi,

We have a Sterling Bath Tub 7104 installed in our bathroom by the builder. Ever since we moved in we have been hearing popping noises and feeling of the tub flexing when pressure is applied (Specially when getting in and out of tub). We contacted the builder who in turn contacted the plumbing company that installed the tub. The plumbing first came in and told us that it is not a problem and normal. They came in again after the noise got worse and cut open the drywall on both sides and sprayed foam under the tub. Also they cut open the sub floor under the tub and made sure that the sub floor was secure.

The issue is however not resolved and still we hear the popping noise and experience the flexing. The builder now claims that it is normal and there is nothing that can be done. Please let me know what the experts on this forum think.

Thanks,

The typical foam won't work as you've found. Most, but not all, brands highly suggest you set the tub in a bed of mortar or some other similar setting, hard substance to provide good, firm support under the tub. Without that, the life of the tub will be shortened. What you have is very common, but not necessarily right.

I'd go on the manufacturer's website, try to find the installation instructions (unless the builder left them with you), read them and see what they recommend in the installation instructions.

Foam won't cut it. You need to set the tub in mortar mix or cement. Some guys used Structolite which is powdered gypsum and works well. I've even seen guys dump a few full buckets of spackle under a tub...anything works better than foam!
We set all ours in cement. They never move after that.

The Sterling instructions don't call for anything under the tub.

If anything is put under the tub, it's normally because somebody went a step beyond what was expected.

I would go with, it's likely normal.

Terry is right - assuming the floor is flat and level, otherwise there will be voids, or the tub will be twisted and it will flex. In this case, the Sterling instructions suggest using a mortar bed.

Charlie

Prepare the Subfloor

http://www.sterlingplumbing.com/onlinecatalog/pdf/1064912_2.pdf

IMPORTANT!
The bath supports must rest directly on a level subfloor.
Squeaking may develop if the bath is installed over a subfloor other
than plywood. In order to prevent squeaking, place a pad between the bath and the subfloor and positioned under the bath supports. We recommend that the pad be made of spun bonded polyester landscape fabric or spun bonded house wrap material. Do not use roofing felt.
Level the SubfloorIf you intend to install this product using a mortar cement bed, do not
level the subfloor at this time. Proceed to the ″Install the Rough Plumbing″ section of this installation guide.
Mortar cement is required to level an uneven subfloor. Do not use
plaster, gypsum cement, or drywall compound for this application, as these materials do not provide adequate structural support.
Spread a layer of mortar cement on the subfloor where the bath supports will be located.
Position and adjust the bath until its outside edge is flush with the framing.
Verify that the bath is level and well supported by the subfloor.
If the bath is not level, shim using metal, hardwood, or other durable material.
Reposition and shim the bath until it is aligned with the framing and level.
If the bath cannot be directly bonded to the subfloor or if decreased movement is desired, consider installing an optional mortar cement bed.
Install a Mortar Cement Bed (Optional)Remove the bath and pad from the alcove.
Do not use plaster, gypsum cement, or drywall compound for this application, as they will not provide adequate structural support.
The bath supports must rest directly on the subfloor.
Spread a 2"(5.1 cm) layer of mortar cement on the subfloor, spreading it so that each area of the bath that will contact the subfloor has mortar cement. Do not spread the mortar cement around the drain area.
Allow room for the mortar cement to expand from the weight of the bath.

Terry's note, I prefer small lumps of mortar, that way they can spread out and conforum to the bottom of the tub. If you lay the mortar in a solid layer, it has to be perfect. And it never is.

Click to expand...

Immediately move the bath into position.
Verify that the bath is level and resting on all supports.
Clean the bath to reduce the risk of damaging the surface.
Place a clean drop cloth or other similar material into the bottom and over the outside edge of the bath. Be careful not to scratch the surface of the unit.

Secure the Bath
Attach the Bath to the Studs
The bath can be attached using the clips (provided), roofing nails, or non-tapered flathead screws. Ensure the roofing nails or non-tapered flathead screws are galvanized or plated.
Verify the studs are within 1/8"
(3 mm) of the bath at the recommended clip or roofing nail locations. Shim if necessary.
For clip attachment (1):
Refer to the Roughing-Insection for recommended clip locations.
At the side of the stud, position the bottom lip of the clip under the flange of the bath, as shown.
Slide the clip into place between the center of the stud and the bath.
Use a pliers to bend the tab of the clip over the bath flange.
Repeat these steps for the remaining clips.
Secure the clips to the studs with roofing nails or non-tapered flathead screws.
Use caution to avoid hitting the bath with a hammer.
For roofing nail or non-tapered flathead screw attachment (2):Position the roofing nail or non-tapered flathead screw above the bath flange. Do not nail or drill through the bath flange.
Install roofing nails or flathead screws over the top of the bath flange at each stud location, as shown. This will pin the bath flange to the studs.
Insure the head of the roofing nail or non-tapered flathead screw will not
interfere with the installation of the wall surrounds or finished wall material.
http://www.sterlingplumbing.com/onlinecatalog/pdf/1064912_2.pdf

The last Steriling I installed was on a concrete floor with mortar support.
It turned out nicely. It's good to see that the instructions mention the mortar now for uneven floors.