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Can You Install Carpet Tiles Over Hydronic Heating?

By Kyle Schurman Created: January, 2021 - Modified: September, 2023

When seeking to install tiles of carpet over hydronic heating, it’s important to pay attention to the type of backing used with the carpet tiling. Some materials may slightly expand when exposed to the heat of the subfloor, which eventually could create warping in the tiles.

The safest type of carpet tile to install over an under floor radiant heating system would be a raised carpet tiling with a plastic base. The raised design relies on a support structure to lift the base of the tile a fraction of an inch above the subfloor, allowing the hot air to flow and circulate without directly impacting any adhesives that may be present in the flooring system.

Carpet on its own is a radiant heating safe flooring. But some materials used on the backside of carpet tiles can create problems with allowing the heat from the subfloor to reach the surface of the floor. Some types of foam backed carpet over hydronic heating will block the heat because of the insulative properties of foam, and the foam may also expand.

How Does a Radiant Hydronic Heating System Affect Floor Coverings?

The hydronic heating system runs gaseous or liquid water through below flooring plastic piping, through a baseboard, or through a radiator. A pump circulates this hot liquid from a boiler, using a thermostat panel to determine the proper temperature for the liquid.

Electric radiant flooring systems are available too that use coils inside plastic mats to deliver heat through the surface of the floor.

Laying floor coverings like carpet over hydronic heating should work well in many situations. However, the key is the type of floor and any backing in use. Some options for floor coverings in this use case include:
  • Hard tiles: These tiles, such as stone or ceramic, will conduct heat well, delivering the warmth from the radiant heating. These materials do have a high cost, though.
  • Wood: Installers should only place engineered wood over a radiant heated floor, or untreated wood could shrink or dry out, creating warping.
  • Foam: Foam tiles are safe to use over radiant heating systems, but they may block some of the heat rising to the surface and expand when exposed to the heat. They will contract again when the heat is no longer present.
  • Vinyl: Vinyl will not warp or dry out when placed over hydronic floor heating systems, but if the vinyl has a foam backing, the foam’s insulation may make the heating less efficient.
  • Carpet: Carpet over hydronic heating works extremely well, much like vinyl. But the backing material in the carpet tiles, primarily foam, could make the heating system less efficient.

These are general recommendations. Individual products within each of these types of materials may have different levels of success when installed over floor heating systems.

How Does Raised Tile Carpet Over Hydronic Heating Work?

To avoid having foam backed carpet tiles create too much insulation to feel the heat from the hydronic floor heating, a raised carpet tile is a better choice when a layout of carpet over hydronic heating is desired.

Raised Carpet Tiles

As the heat rises from the subfloor, the raised base on the carpet tile creates a tiny air pocket between the subfloor and the plastic base on the carpet tiles. This creates a more efficient delivery of the heat from the subfloor versus having a foam backing on the carpet tile placed directly on the heated subfloor.

The plastic material will not expand or warp when exposed to the radiant heat in the subfloor. The raised modular carpet tile will last just as long as it would when installed over the top of a non-heated subfloor.

The plastic supports on the base of the tiles are extremely sturdy, supporting the weight of furniture and people walking on them without creating a feeling of instability.

Another benefit of raised plastic base carpet tiles is that they don’t require any special requirements for care. Just vacuum them as with any other type of carpeting for regular cleaning.

What Are the Best Raised Carpet Tiles for Use With an In-Floor Heating System?

A popular choice when seeking carpet over hydronic heating is the Carpet Tiles Modular Squares. These tiles use a hidden interlocking system to securely connect the tiles without the need for adhesive. Once the installer pops the pieces together, the interlocking system is not visible.

Carpet Tiles Modular Squares

With a convenient coverage size of 1 square foot and a weight of 1 pound per square tile, one person can perform the installation in very little time. The tiles pull apart just as quickly for placement into storage.

These tiles work best when placed over a hard subfloor, such as concrete, which is frequently what’s found with hydronic heating systems. The firm subfloor surface allows the plastic base to sit sturdily and simplifies installation.