How well do Legalett air heated slab on grades work?


How well do Legalett slab on grades work?

Steve Sykes Aug. 18, 2019Last updated: Aug. 4, 2020

We are planning a build for June 2020 in Prince Edward County, Ontario where there is 1 ft of topsoil, 2 ft of clay and then bedrock.  Structure planned is a bungalow of ~ 2000 sq ft with a 3 car attached garage.  Based on the promotional material, the Legalett system seems like a good choice to avoid sump pump and optimze accessibility.  However -- we can't seem to find evidence that this concept has gotten traction over the years in Ontario, specifically in Prince Edward county. Specific questions we have include:

1) What are some potential issues with the approach?

2) How are those issues usually addressed?

3) What is the long term track record of this technology?

4) Is there any reason you can think of why the County of Prince Edward would have any issues with issuing a permit for, inspecting, and issuing an occupancy permit for the finished product?

5) Is there anything special we would need the home designer to be aware of, as they pit tohether the plans and construction drawings, if we opted for this approach for the foundation?

6) We would like if possible to use local people as primary constructors, and we are also capable of (and want to add where possible) sweat equity. Is this feasible with the Legalett system? We also believe we have a good local excavator for the septic and foundation work.

7) If so, would non-Legalett trained people need any special knowledge, experience or skill beyond what they would normally need to build such a house if it were on a crawl space or basement? What I mean here relates to the part above the foundation; i.e. the main house and garage construction.

8) Are there any homeowners we can speak to, for references, for comparable projects? Ideally we wish to understand any issues that might arise during the planning, execution or post-project.

Any info you can provide would be welcome, and thanks. 

Responses (3)

John Woolfrey
John Woolfrey April 1, 2021, 9:32 p.m.

As I plan my home -- with the Legalet air-heated floor in mind, I keep wondering about possible flooding entering the furnace. I'm planning drains near the water heater and washing machine for any mishaps, but what's to prevent any water from seeping into the furnace, which is sunken into the concrete floor?

Emmanuel Cosgrove
Emmanuel Cosgrove April 2, 2021, 1:45 p.m.

The legalett heater box that is embedded in the floor has drain holes in each corner of the box, and it sits on an EPS foam base that has holes that line up with those in the box, so in the even of a surface flood from a water heater or washing machine, any water that finds it's way into the box drainsharmlessly  through to the stone beneath the slab.