Legalett / Discussions

I will be hiring an architect to design my single floor 2200 sq. ft. home in coastal RI. My hope is to be as passive and net-zero as possible. We intend to have a cold climate air source heat pump that will serve as our sole source of heating and cooling, plus an ERV. I believe we are in Zone 5. We are thinking of a hy...

I am in the early stages of planning a new home build. Am I correct in assuming that slab on grade constuction with passive floor heating would rule out the use of a heat pump. Also I would question your depiction of crawl spaces as damp and moldy. In a previous house I built with ICF walls the crawlspace was warm and ...

...Legalett slab on grade with air heated floors. There is not as much heat in air so it doesn’t over shoot as much, and the entire system is embedded in the floor so there would be no ‘boiler room effect’ of overheating at the manifold in your mechanical room. Concrete is highly conductive, and even in a home kept at a t...

Why is the Legalett air heated foundation system better than radiant heat mats which are electric and nothing is wasted heating the air? I wouldn't say one is better than the other, all forms of under floor heating have pros and cons. It really depends on whether its a new build or a renovation, and how much of the flo...

...Legalett Thermalsill insulated door sill for slab on grade floors is only available with Legalett-designed slabs unfortunately. It is a proprietary design that was created as a solution for Passive House slabs, and I honestly don’t know of any other commercially available product. Sorry about that Shaun! 

...Legalett ThermalWall panels, but we do like them, we just haven’t gotten to featuring it yet! Legalett provides prefab slab on grade form kiits with air heated floors as you mention, and the ThermalWall panels were a compliment to that, they were originally developed to improve the performance of ICF basements but they...

...Legalett system or does Legalett system have to be turned on and warming the slab as well? This is a good idea, as heat pumps can be up to 3 times more efficient that other heat sources. We consulted with a Legalett engineer to be sure, and they would like you to run your Legalett air-heated floor system at least a bit...

...Legalett - I see from their site that they offer conrete deck forms that utilize EPS and air-heated in-floor tubing as the FPSF. This made me go hmmmm... might this be an option, on engineering pilings, for my lot? Any thoughts, or should I just get to levelling the site? Thank you and take good care, Pam (Laurentian V...

I am building a small structure on a monolithic slab and trying to reduce the amount of foam in the assembly.  I'm wondering if I could use comfortboard sheets as my horizontal frost protection skirting on the outside of the slab?  It is an 18x16 slab, on a very well drained crushed stone pad.  Roxul tech support was n...

I am building a foundation for a floating slab. The ~4' foundation walls sit on footings.Is it better to insulate on the inside or outside of the foundation walls, or both inside and outside? I’m wondering why you are going with a 4-foot-deep frost wall for a slab on grade. There are much cheaper and easier ways to bui...

...Legalett air distribution part but keep the forming? I'm trying to achieve the least amount of electrical use required to make the in floor system work. Pumps vs fans, liquid vs air for heat transfer, such a complex comparison! Advice please. The Legalett air heated floor system can run either with electricity or gas. ...

...Legalett raft slab on grade kits but I don't think they provide advice on grading. Any advice would be appreciated - and also where to find a good engineer - there seem to be a lot of cowboy contractors out there!  A raft slab is different than standard slab on grade construction, and it pretty much by definition needs...

...Legalett systems look very good especially their air radiant system. The question for us is what happens in winter when we are away for a few weeks? We'd need to keep heat on? At what level? Would pipe size in the Legalett air radiant system  (2" or 4") make a difference? Would it simply be better to go hydronic or ele...

...Legalett supplies across North America and they may have  a list of local installers.

...Legalett raft slab has an optional air heated radiant floor, but it is not necessary. They are installed in all climates from the far north to the south, and even in cold climates they don’t always include floor heating. Many Passive House home builds that use a Legalett insulated slab base don’t install heating system...

Hello,  Reading your article on air heated radiant floors and have a few questions: What is the cfm on such a system  (per loop or run)? What temp is run through the system? Are there any other providers of such systems than Legallett in the USA? Thank you for your help,  Marty Legalett supplies air heated radiant floo...

...Legalett brought up for the approval process?  Much appreciated, Matt.    Hi Matt, we're happy to hear you’re finding what you need on the site. So about your first question, air heated floors are just as effective and reliable as hydronic radiant floors for heating your house. This page explains the differences well –...

We have significant water issues, and would like to 'get rid of' our basement. We wondered about 'backfilling' our basement, raising the house to second story height, and building a new ground floor on a slab on grade foundation, so to speak. We live in a high ranch, with the front door cut into the existing foundation...