Min. concrete over radiant heat pex-al-pex (MLC) tubing

mercedes

Finally layout the Foamular 250 foam board square cut but only can find tongue and groove boards. Now the slab is going to be 6". I brought rebar chairs 2.5" using #4 rebar my clearance to the top of the concrete is 1 1/4 ". I think this is to shallow. Thoughts?

mercedes

Sorry the tubing will be 1 1/4" from the top of the concrete.

Zman

I think that will be perfect. Nice job.
Check this out https://www.pmengineer.com/articles/92439-exploring-all-the-aspects-of-tubing-depth

hot_rod

the concrete folks suggest 3 times the aggregate size over any tube, bar, etc. Most red mix plants use a 5/8 rock.

In some 1-1/2" thin slabs we requested a 3/8 "pea gravel" mix. Smaller aggregate, lest strength, but for a residential floor not an issue.

mercedes

Zman and hot rod

Thank you for the advice and help. Here are some pictures of my radiant heat for my garage.
The Pex-Al-Pex is dead center of the slab 3" (slab total height 6")
Stego vapor barrier 15 mil (in yellow on the perimeter)
2" Dow Tongue and groove foam boards (could not find sq edge w/o snap lines
2 1/2" rebar chairs (18" on center) with # 4 rebar criss-cross
Uponor pex rail tie to the lower rebar to hold the tubing in place
Uponor Pex-AL-Pex tubing 1/2" 885' total
Caleffi 4 port manifold 6686D5S1A with flow meters
Caleffi Pex-Al-Pex adaptors for the manifold 6825400

Thank you again
Dan

mercedes

hot_rod

Looks nice. How much over the top of the upper rebar? You want a good inch or more to prevent “road map” cracking

mercedes

Hot rod

I will have from 1 1/2 to 2" also in the spring I will have 1/2" stone tile on top. Thanks Dan

hot_rod

Great! A cleavage membrane or brush on product it a good idea to keep any slab cracking from telegraphing to the tile

The Tile association websites have good info for that detail