With a non insulated crawlspace under the plywood you should use insulation boards prior to installing the heating coils.
How to install heated floor on plywood.
Instead of blowing hot air through a vent or pumping hot water to a baseboard radiator along the wall radiant heat warms up the entire floor.
Using electric radiant heat under wood floors.
Radiant heat systems typically involve hot water running through tubes embedded in concrete or stapled to plywood subfloors but there are many variations.
And make sure the fasteners are galvanized to prevent rusting.
A good compromise is to install the hydronic system right in a concrete slab and install the wood on the concrete.
Plywood is best for subfloors because it holds nails and screws more securely.
Installing radiant tubing on top of a subfloor.
The simplest type of radiant heat system in frame construction involves stapling tubes to the underside of the wood subfloor between the floor joists.
But that said even a wood floor will warm up and heat you and the room quite well.
Either through pipes carrying hot water embedded in or directly below the floor or via electric mats in or below the floor.
The heat is made possible in two ways.
Radiant heat in frame construction.
Oak hardwood flooring to match the rest of the house flooring but we had some floor height issues to deal with first.
This movement in the plywood can cause the grout to crack.
In our four season porch we decided to install 3 4 in.
These heated floors are a project best done when overhauling or changing the floor covering of an existing room or when adding a new room.
Many people ask the question how can i install radiant heat if i don t have access to the floor from below one way is to go with a manufactured grooved board system that you can put down and simply lay the pex in it.
This in floor heating system consists of one thin continuous cable heating element woven into a mat that you install under the tile.