ThermalSheet Insulating Underlayment (2’ x 3’) - 6 Sq. Ft. - 1 Sheet
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Notices
Quebec Repairability Notice
Avis important pour les consommateurs du Québec:
WarmlyYours n’offre pas de services de réparation pour ce produit. Les seules pièces de rechange disponibles sont les kits de raccordement (splice kits) ; l’élément chauffant lui-même n’est pas offert comme pièce de rechange. Si votre système de chauffage par le sol intérieur tombe en panne pendant la période de garantie, nous remplacerons l’unité complète conformément à notre politique de garantie. Notre équipe d’assistance technique est disponible 24h/24 et 7j/7 par téléphone pour toute aide à l’installation ou au dépannage. Pour plus de détails, consultez notre politique de retour. Cet avis est fourni conformément à la Loi sur la protection du consommateur du Québec, article 39 (telle qu’amendée en 2025).
Important Notice for Québec Consumers:
WarmlyYours does not provide repair services for this product. The only replacement parts available are splice kits; the heating element itself is not available as a replacement part. If your indoor floor heating system fails within the warranty period, we will replace the entire unit according to our warranty policy. Our technical support team is available 24/7 by phone for installation and troubleshooting assistance. For full details, see our Return Policy. This notice is provided in accordance with Québec’s Consumer Protection Act, section 39 (as amended in 2025).
Support Questions
Showing 10 of 16 questions
No, for the installation of an Environ heating system with a floating floor like laminate, it is not necessary to adhere the ThermalSheet underlayment to the subfloor. The underlayment should instead be allowed to float freely on the subfloor. Make sure to stagger adjacent sheets of underlayment and tape them together to prevent any overlaps, ensuring a flat and even layer beneath your flooring. This method helps accommodate the natural expansion and contraction of the floating floor.
ThermalSheet Insulating Underlayment is a synthetic cork, a lightweight thermal barrier made of hemi-crystalline thermoplastic.
WarmlyYours recommends ThermalSheet underlayment when installing a floor heating system over a concrete slab to prevent heat loss and protect against moisture. It will not rot, support mold and mildew, or absorb moisture.
- ThermalSheet synthetic cork underlayment (6mm) has a 1.5 R-value, crack isolation up to 1/4“, reduces sound by up to 22 dB, and is Robinson tested (TCNA) and rated for residential loads.
- Cork (6mm) has a .72 R-value, crack isolation up to 1/32“, reduces sound by up to 23 dB, and is Robinson tested (TCNA) and rated for residential loads.
Yes, radiant floor heating can be a primary heat source if its heat output exceeds the room's heat loss. For best results, we recommend using a 15-watt system, covering at least 80% of the floor, and ensuring the space is well-insulated. Use our Heat Loss Calculator to verify your specific needs.
Yes, radiant floor heating is an excellent primary heat source for tiny houses in mild to moderate climates. Because tiny houses have small footprints, the 15-watt output of TempZone™ can easily maintain comfort while saving valuable wall space. Ensure the structure is well-insulated and use our Heat Loss Calculator to confirm.
Yes, we strongly recommend installing insulation like ThermalSheet™ over concrete slabs. Concrete acts as a "heat sink," absorbing warmth that should go to your floor. Insulation directs the heat upward, significantly improving efficiency, reducing warm-up times, and allowing the system to function effectively as a primary heat source.
Underlayment is recommended for floating floors (laminate, LVP, wood) and installations over cold subfloors like concrete. It provides thermal insulation to prevent heat loss and improves system efficiency. For tile and stone, the system is typically embedded in thinset, so a separate underlayment is often unnecessary.
WarmlyYours TempZone™ Flex Rolls and Easy Mats deliver 15 watts per square foot, the maximum allowed by the National Electrical Code. This provides 25% more heating power than the 12-watt industry standard. TempZone™ Cable can be spaced to deliver between 8 and 15 watts per square foot depending on your needs.
Yes, electric radiant floor heating is ideal for basements because it warms the cold concrete slab and provides consistent heat from the ground up. In well-insulated finished basements, it can serve as the primary heat source, turning a typically chilly space into a comfortable, year-round living area.
Radiant floor heating can heat a sunroom if the space has high-quality insulation and double-pane glass. Since sunrooms have high heat loss, a 15-watt system is essential. In extremely cold climates or poorly insulated sunrooms, it is best used as a supplemental source to keep the floor comfortable.
Yes, radiant heating is highly efficient in cold weather. Unlike forced-air systems that lose heat through ductwork and rising air, radiant heat warms objects directly via far-infrared energy. This method is up to 45% more energy-efficient, providing consistent comfort while significantly lowering monthly heating costs in frigid environments.
The best home features for cold climates include a simple gable roof to shed snow, covered entrances for protection, airtight triple-pane windows to prevent heat loss, and radiant heating systems. These features work together to maintain interior warmth, reduce energy bills by up to 25%, and ensure structural safety during harsh winters.
Most systems provide only 12 watts per square foot, which often lacks the power for primary heating in cold climates. WarmlyYours TempZone™ delivers 15 watts—a 25% increase. This higher output allows the system to overcome heat loss more effectively, providing reliable primary warmth even when outdoor temperatures drop.
Documents
Technical Information
Installation
- ThermalSheet Insulating Underlayment Installation Instructions (English)
- ThermalSheet Insulating Underlayment Installation Instructions (Spanish)
Sell Sheets
Specifications
Insulation Specification
| Acoustic testing on 6" slab, no ceiling | IIC 52 wood construction. FIIC 59 - 7.5″ concrete slab. ΔIIC 20 - 6″ concrete slab |
| Compressive Strength | 41 psi at 25% strain, 54 psi at 50% strain, and 110 psi at 75% strain |
| Material | Expanded Polypropylene (EPP) |
| Thermal Insulation | 1.5 R-Value |
Product Dimensions
| Coverage | 6 ft² |
| Depth | 0.2362″ |
| Length | 36″ |
| Weight | 0.4 lbs |
| Width | 24″ |
Identifiers
| SKU | TS-SH6MM-24x36 |
| UPC (GTIN-12) | 881308077037 |
Warranty / Certifications
| TCNA Robinson test | Residential |
| Warranty | 5 years |