To put an above floor radiant heat system in the Momplex, we first layed strips of 3/4" plywood in pattern on top of the subfloor. There's 3/4" gaps in between for running tubing of hot water through the floor. Then we placed heat transfer plates (basically aluminum foil, just a little thicker) in the grooves. The heat transfer plates will draw the warmth out of the tubing and spread it across the floor.

Today, we'll be putting the tubing in the grooves and hooking up to manifolds.  If this was a road, today would be paving day!

Here's the manifolds we have purchased. We've been kicking ourselves for not just making up our own as we did for the water supply lines because with the off the shelf manifold, we have to modify it anyway to suit our needs. 

The manifold comes as one so that it can be pressure tested.

We cut it apart into two manifolds, one for a supply and one for a return.

And then mount to a board,

Then on the ends, the manifolds elbow off to the main supply and returns that run to the boiler. Making sense to you?

But we have one messy problem. It's kinda like a freeway system all ending at the same spot. The mother of all mergers ... only there's no overpasses. Tubing lines can't cross over each other. The manifold is designed to sit inside the back closet. Eight lines need to be run to and from it. And they can't overlap. We've been dreading cutting out plywood groves to manage all this ... even considered just laying plywood down and getting a 3/4" router bit and cutting channels out. But the Ram had a brilliant idea. What about an underpass?

Why not fill the closet with plywood - it does not need to be heated.

And then drill holes at the end of each water line

Like this ...

Here's from the underside ...

And up to the manifold? Pretty smart, eh? I thought so! The tubing doesn't bend super well - it's more rigid and you don't want to kink it and create a leak. This method was super smart because it put the water lines right up under the manifold at the right angle.

From the manifolds, we just start placing tubing in the grooves.

This is the easy part - we've already built the road, it's just time to pave it!

It really helps to have one person hold the roll

And another person place the pipe in the grooves.  We are very thankful to Junior for helping us out with the heat system.

What started out as one line snaking down the hall

Quickly became entire rooms filled with tubing.

Here's the kitchen and hall area

And around the stairs.

Where the tubing bends, it tended to pop up out of the grooves.  So we took scrap pieces of heat transfer plates and stapled those suckers down.

For those void ends, we filled in with wood pieces, cut to pattern, following the natural curve of the pipe.  The scrap pieces are used to fill in the corner voids.

And then we loop it all back to the manifold in the closet

The Ram's underpass merger system worked like a dream!

Tubing lines get connected to manifolds,

And it all passes the pressure test!

I can hardly believe it, we've completed the upstairs heat system!

We'll still need to run supply and return lines to the boiler from the manifold - and of course install the boiler itself - before we start getting heat out of it, but it's an awesome feeling to know one more step is done!

Thanks for letting us share our Momplex story with you!  Have you installed radiant?  Would you?  We'd love to hear your story too!