You only do it once,so do it right.
Once the concrete is poured, whatever is under it is there for good. Ask your builder for the below-grade insulation that holds its R-value.
For homeowners
You can upgrade a roof later. Not a slab.
Roofs and windows get replaced all the time. The insulation under your concrete floor is there for good, and it's the part of the house most people never think about.
- Warmer floors, and lower heating and cooling bills.
- Keeps its R-value in the ground. In a 15-year test, EPS kept 94%; pink and blue foam board kept 52%.
- Termiticide is built in and protects your home from termites.
A Well-Insulated Home Starts at the Foundation
Everyone thinks about insulating the attic and the walls. Almost nobody thinks about the floor. Yet studies put as much as 25% of a building's energy loss on uninsulated foundations, crawl spaces, and slabs. Lexar puts a permanent layer of insulation between your concrete and the ground, summer and winter.
Lower Energy Bills
An insulated slab holds the heat in during winter and the cool in during summer, so your heating and cooling run less. That's true for a house, a shop, a barndominium, or a basement.
Perfect For Radiant
If you're installing heated floors, under-slab insulation is non-negotiable. Without it, you're paying to heat the soil under your house.
Termite Protection
Termiticide is built in and protects your home from termites.
The 15-Year Test
Researchers dug up foam insulation that had spent 15 years in the ground and measured how much R-value was left.
Source: EPS Industry Alliance, Technical Bulletin 103 (2008). EPS vs. XPS after 15 years below grade, St. Paul, MN.
They look similar.
They aren't.
Most builders default to pink or blue foam board (XPS). It works by trapping manufactured gas inside the foam, and that gas does a lot of the insulating.
Over the years the gas leaks out, and the insulation value drops with it. In the 15-year test, XPS lost nearly half.
Lexar is EPS. It insulates with trapped air, not escaping gas, so the R-value you pay for stays in the ground under your floor.
See the full comparisonAsk your builder about Lexar.
Most homeowners go with what their builder recommends. Send yours a note, or get a quote and we'll connect you with a local dealer who can supply the job.