Is it worth insulating under only bathroom footprint of basement slab?
jmarkantes
| Posted in Energy, Heating & Insulation on
Adding a bathroom in the basement we cut the concrete for the exact footprint of the bathroom. The plan is when we pour, to come within ~1″ of existing concrete to add electric heat and tile. Is it worth adding rigid foam under this pour? There won’t be a thermal break between the new and existing concrete. But it will be heated. I’m going back and forth if it will be worth it, appreciate any feedback.
Thanks,
Jason
Replies
We have hydronic in our entire first floor concrete and tile. In addition to the under slab insulation we also separated the slab from the block foundation with foambd.
Limited the heat transfer from under slab as well as around the perimeter.
Thanks for the reply. So do you think it would still have been worth it if you hadn't also foamed around the perimeter? That's what we're debating. I know under slab it will make a different, but for such a small area, and we can't foam the perimeter, if it's worth doing at all.
Well, I’m just a dumb carpenter.
When we visited our daughter (who keeps the house cool) and we showered in her basement bathroom, a cheap small old space heater did the work. Plugged it in and stripped. Her bath probably 6x10.
I don’t know how much extra you will be heating the perimeter slab.
Keep the door shut, local thermostat and set it low. The heat in the slab will still migrate but maybe if you’re lucky, not much.
I know this, our slab is warm. But, we live in the ground……2 story built into the hill. Passive solar and a Tulikivi heater. Hot water in the first floor and upper baths. Heck, unless below zero, the Tulikivi does the job for a woman who likes to be warm.
So, beats the heck outta me……
Best of luck!
Edit. By the way, you look like a tile setter I know, Fast Eddie.
Appreciate the detail!
Not a tile setter, and don't have a cool nickname. :)
Cheers,
Jason