I've heard that insulating under my tub with closed-cell spray foam can really help keep the heat in and reduce the chilly feel when standing on it. My contractor usually uses a sand and mortar mix for setting tubs, and I have an acrylic tub. Given that I live in a poorly insulated house and want to make sure my tub doesn't warp or feel like ice, should I really consider insulation? Is the sand and mortar method good enough, or do I need the foam too? Maybe an extra hot water boost would make insulation unnecessary?
3 Answers
Insulation definitely helps! What do you mean by 'move the needle' though? If you’re asking if it’s worth the extra money, that really depends on how much time you spend in the bath. Are you a long bath person?
In my experience, the mortar bed is crucial for stability. Your contractor is right about that. It won't really help with heat retention unless you have heated floors underneath. But if you love long baths, insulation can really make a difference. My hot tub stays warm for days with spray foam, so it definitely works! Plus, adding it now is way easier than later!
I have a fiberglass tub and I added unfaced fiberglass insulation before setting it in mortar. Honestly, it has worked wonders compared to my old cast iron tub! I’m not a fan of spray foam due to its odor and mess, so I skipped that.
Totally agree with you! Doing it now is much smarter than regretting it later.