PROVA Flex-Heat Uncoupling Membrane for Radiant Floor Heating Cables
PROVA Flex-Heat is an uncoupling membrane purpose-built for radiant floor heating cables — combining PROVA's proven crack isolation and vapor management technology with integrated cable-spacing studs designed for precise, consistent heating cable layout. It performs every function of a standard uncoupling membrane while providing a dedicated channel system that spaces heating cables at the correct 3" interval from the start of installation.
The PROVA Heat membrane's 1" stud layout allows most electric heating cables up to 0.2" (5 mm) in diameter to seat firmly at 3" spacing — the standard recommended by most cable manufacturers for balanced heat distribution.
At only 6.5 mm (0.26") thick, the overall assembly stays close to existing floor height, and the open-air vapor management channels beneath the fleece layer allow any residual substrate moisture to dissipate without becoming trapped under the tile.
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Purpose-built for radiant heating systems — studs accept heating cables up to 0.2" (5 mm) thick; set cables at 3" spacing using every third row of the 1" stud grid for optimal heat distribution
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ASTM C627 Extra Heavy Performance Rating — the highest Robinson floor test classification; suitable for residential and light commercial tile applications including high-traffic areas
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Crack isolation protection — decouples the tile assembly from substrate movement, stopping subfloor cracks and seasonal deflection from transmitting into grout lines and tile over time
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Vapor management system — open-air channels below the fleece layer allow residual moisture in the substrate to escape, preventing trapped moisture from compromising the tile bond or substrate
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Ultra-thin 6.5 mm (0.26") profile — minimal height gain at transitions; can also be installed without heating cables as a standard uncoupling membrane to level up to adjacent flooring
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Versatile installation substrates — suitable for cement slabs and wood subfloors for interior residential and commercial tile installations
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Available in 15–161 sq ft sizes — choose the coverage that matches your heated floor area for a clean, waste-free order
Premium polymer-modified thinset mortar is required for bonding the PROVA Flex-Heat underlayment to the substrate and for setting tile on top. Compatible with LuxHeat floor heating cables and most other electric radiant cable systems. Free shipping to the contiguous US on all orders.
Frequently Asked Questions
Is the PROVA Flex-Heat membrane compatible with any heating cable, or only LuxHeat?
PROVA Flex-Heat works with most electric floor heating cables up to 0.2" (5 mm) in diameter — including LuxHeat cables and most other brands. The 1" stud grid allows cables to be spaced at 3" intervals, which is the standard spacing specification for most radiant heating cable manufacturers. Check your specific cable's installation guide to confirm the required spacing before starting.
Does PROVA Flex-Heat require a special thinset?
Yes — premium polymer-modified thinset mortar is required both for bonding the membrane to the substrate and for setting tile on top of the membrane. Standard non-modified thinset is not recommended with any uncoupling membrane. Using the correct thinset is essential for proper adhesion and for the long-term performance of the tile assembly.
Can PROVA Flex-Heat be installed on a wood subfloor as well as concrete?
Yes. PROVA Flex-Heat is suitable for both cement slabs and wood subfloors for interior installations. The crack isolation layer decouples the tile assembly from the natural flex and movement of wood-frame construction — one of the most common causes of grout and tile failure on wood subfloors. It is a particularly good choice for wood-frame homes where floor heating cable and tile are being installed together.
