Insulation in cavity of drop in fiberglass tub
user-87499
| Posted in Energy, Heating & Insulation on
Goal is to capture and preserve the warm temperature of bath water in a drop-in fiberglass tub with framed and tiled surround. New construction. Can the space, that will surround the tub, be insulated prior to tub placement? Foam or fiberglass bats?
Hot water will be supplied by a electric tank water heater (not tankless).
The exterior wall, which the tub surround butts against, Â has only R13 open cell spray foam. Unheated concrete slab below tub and air pockets exist all around where insert tub will go. Seems the logical thing to do but want to be wise about this and would appreciate feedback. Thank you.
Replies
quick thought is to use rigid foam under the tub and in any voids in the framing it will drop in to - fill the void space on the exterior side with low expansion foam that will expand to fill that area between the tub and the wall
good luck
Thank you. A photo has been added to better describe the space.
looks like you have some space at the wall side to put some rigid foam for insulation - other thought is to use mineral wool (water proof, mold resistant) to fill the entire support structure and then "line" the tub area with a flexible foam
only concern/question now how are you going to do the plumbing and have access?
I wondered the same thing when renovating our bath. I wound up putting in a bunch of rigid foam that I had on site and my bath tends to stay pretty warm for a long time. It's a cast iron though, so that might have something to do with it or make it worse?
Either way, the foam has been there for six years and the house hasn't fallen over yet.
https://www.finehomebuilding.com/forum/insulating-an-acrylic-bathtub