specific installation instructions

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Phase 7 - Install Insulation

Appendix 1: Types of Construction and Applications

Insulate under the subfloor for better performance and efficiency of the system. Refer to the

Appendix for diagrams and insulation recommendations.

Type of Construction

Mortar Applications:

Thin-set and thick-set (self-leveling) mortar applications are illustrated to the right.

If a backer board or plywood sheeting is used to strengthen the floor, or if the heating

wire will be placed directly onto the slab, install in the thin-set mortar bond coat above

these materials.

If a thicker mortar bed, or self-leveling concrete, is used to strengthen the floor, the

heating wire can be installed in either the mortar bed (dry-set) or in the mortar bond coat

directly below the tile or stone.

The heating wire is generally installed above the self-leveling mortar in a thin-set bond coat.

Use plastic lath instead of the typical metal lath when installing in a self-leveling layer.

Self-leveling Mortar Applications:

These are appropriate applications if installing engineered wood, vinyl, laminate, or carpet

floor coverings. Attach the WarmWire to the subfloor or slab, then pour self-leveling mortar

1/4" to 1/2" thick according to manufacturer’s specifications. Install floor covering after the

mortar has cured.

Special Precautions

Isolation Membrane: Install the heating wire above the membrane, whenever possible,

unless recommended otherwise by the membrane manufacturer.

Insulation: Insulation dramatically enhances the performance and efficiency of floor-warming

systems. Do not install rigid insulation directly above or below backer board or mortar.

Mosaic Tile: When installing mosaic tile, it is recommended to apply a two-step process.

First, embed the heating wire in a thin self-level mortar bed (1/4"–3/8"), then thin-set the

mosaic tile according to typical practice.

Expansion Joints: Do not install heating wires through an expansion joint. Install heating

wire right up to the joint, if necessary, but not through the joint.

Never bang a trowel on the Heating Wire to remove excess mortar from the trowel. This

could damage the heating wire.