Make your own radiant floor sandwich

I'm about to embark on building my own radiant subfloor sandwich, and wondered if anyone had experience doing it? It's not financially efficient to use the Wirsbo (or similar) prefab products, so I was going to lay 1x6's and place the tubing in channels lined with aluminum to diffuse the heat over the floor.

We're finishing it with bamboo on top, nailed down directly if that matters.

Thanks, Matt

Some things to consider

Some info would help get good answers and suggestions.

Is the heating over concrete or over a wooden subfloor on joists? If concrete, you may want to insulate below to make sure the heat goes up and not into the ground.

The concrete that is usually poured over heating tubes is in contact with the tubes and increases the heat transfer rate. Aluminum in the channels will reflect heat but may not be as efficient for heat transfer to the floor where you want the heat.

A wood floor is usually put over a continuous subfloor (I'm familiar with oak.). Will you have a subfloor over the tubes? Or will the 1x6s be close together to serve as a subfloor? Will the 1x6s be nailed to joists or a subfloor?

Is it electric heat or circulating hot water?

Answers...

Is the heating over concrete or over a wooden subfloor on joists?
It's being installed over a wooden subfloor on TOP of concrete. We put down Dricore to provide both ventilation gap and a solid nailing surface. According to the folks I spoke with there, it's an approved installation design.

Will you have a subfloor over the tubes? Or will the 1x6s be close together to serve as a subfloor?
The plan is to use the 1x6s as the subfloor, with grooves for the tubing (and the aluminum plates (12 inches wide) molded into the grooves, places UNDER the tubing...sorta looks like this:

I was going to directly nail the bamboo on top of the sandwich (no additional layers of rosin paper, etc.)

Will the 1x6s be nailed to joists or a subfloor?
It'll be nailed to the Dricore

Is it electric heat or circulating hot water?
Circulating hot water