GenieMat® RST

View our Product FAQ for answers to common questions about GenieMat® RST products.

A quality acoustic underlayment must be both resilient and dense to effectively reduce impact footfall noise and airborne sound transmission. The GenieMat® RST Rubber Underlayment is engineered to meet both of these performance standards across all available thicknesses.

The GenieMat RST Rubber Underlayment delivers proven performance for impact noise reduction, crack isolation, and VOC-free indoor air quality. Whether used over concrete or wood, it provides a reliable, long-lasting acoustic barrier that enhances comfort and sound control in residential, commercial, and multi-family flooring systems.

Choosing the Right GenieMat RST Thickness

• GenieMat RST02 (2mm) and GenieMat RST05 (5mm) are ideal for floors installed above ceilings with resilient clips or resilient channel systems.
• GenieMat RST10 (10mm) and GenieMat RST12 (12mm) are best for assemblies where the ceiling below is fixed directly to framing or when maximum sound isolation is required.

Thicker RST models provide greater impact noise reduction and airborne sound control, making them ideal for multi-unit residential buildings, offices, and high-performance studios.

Proven Acoustic and Material Performance

GenieMat RST has been independently tested for use under nearly all common floor finishes, including tile, stone, hardwood, laminate, vinyl, VCT, and carpet. It installs directly over wood, concrete, or steel subfloors. This rubber underlayment also meets: ANSI 118.12 – Crack isolation membrane standard and ASTM D5116 – Indoor air quality standard for zero VOC emissions.

GenieMat RST Over Concrete Subfloors

Rubber underlayments perform best when installed over or under concrete subfloors. The mass and rigidity of concrete allow the rubber to compress properly, providing superior resilience and impact sound absorption. Whether on full pour or lightweight concrete, GenieMat RST adds measurable acoustic isolation and comfort underfoot.

GenieMat RST Over Wood Subfloors

Rubber underlayments behave differently over wood subfloors, which are naturally more flexible. To achieve the same level of performance as concrete systems:

• Fix structural deflection between joists (see Fixing Structural Deflection).
• Or, add mass by layering roughly 7 pounds per square foot of material over the subfloor or GenieMat RST.

Layering directly over the subfloor enhances low-frequency isolation and reduces footfall vibration, while layering above the GenieMat RST increases STC ratings by a few points. Suitable materials include plywood, OSB, MDF, drywall, lightweight concrete, or cement backer board. While not required, layering is strongly recommended to maximize acoustic performance in wood-frame structures.

Enhanced Soundproofing Options

Adding Green Glue Noiseproofing Compound between floor layers further improves both impact and airborne sound isolation. For even greater results, combine GenieMat® RST with GenieClip® resilient sound clips or resilient channel ceilings. The highest-rated floor/ceiling assemblies feature resilience in both the floor and ceiling systems.

Read our article Maximizing Rubber Underlayment Performance for more detailed information.

Read our article Fixing Structural Deflection for more detailed information.

The GenieMat® RST can be cut with a standard razor knife. The rubber can have an odor to it when it first arrives. This smell typically fades away similarly to a newly painted room. If the smell lingers or the user is sensitive to the smell of rubber, cover the rubber with a 4-mil plastic sheeting.

Installation For Floating Finished Floor Install

Follow these steps if installing a floating hardwood or laminate, nailed down hardwood, or carpet over the GenieMat® RST.

1. Roll out the material and cut to fit, leaving up to a 1/4" gap on the perimeter.
2. Butt the seams together, avoid overlapping.
3. Cover seams with standard duct tape. Fill in gaps with acoustical sealant before taping.
4. Install flooring directly to the GenieMat® RST or to the additional layering over the GenieMat® RST if applicable.

Installation For Fixed Finished Floor Install

When using grouted or fully adhered flooring materials, the GenieMat® RST must be adhered to the sub-floor with a suitable adhesive. The finished floor can then be installed directly to the GenieMat® RST.

1. Use a 1/16" notched trowel to apply a urethane based adhesive to the sub-floor.
2. Carefully lay the GenieMat® RST into the wet adhesive to avoid wrinkles or air pockets. A 40+ pound roller is recommended for adhering the thinner RST-02 or RST-05.
3. Cut the GenieMat® RST to fit, leaving up to a 1/4" gap on the perimeter.
4. Continue with the next row, butt the seams together, avoid overlapping. Complete each row before moving to the next.
5. Cover seams with standard duct tape. Fill gaps with acoustical sealant before taping.
6. Install flooring directly to the GenieMat® RST or to the additional layering over the GenieMat® RST if applicable.

• GenieMat® RST Simple Installation Manual
• GenieMat® RST Technical Installation Manual
• GenieMat® RST Technical Installation Manual For Vinyl Floor Coverings

*All test results shown in this table were achieved through third party testing from accredited laboratories. The full test is available upon request.

GenieMat® RST Rubber Underlayment is available in standard roll sizes, with one roll size per thickness. Partial rolls or oversized rolls are not available for purchase. To ensure full coverage, it’s best to overestimate by about 5%, which typically provides enough material to account for cuts, seams, and layout adjustments.

Before ordering, we recommend sketching your room dimensions and planning the installation layout to accurately calculate the number of GenieMat RST rolls required for your project. This approach ensures an efficient installation with minimal waste and proper material coverage for optimal soundproofing performance.

• GenieMat® RST02 Product Specs
• GenieMat® RST05 Product Specs
• GenieMat® RST10 Product Specs
• GenieMat® RST12 Product Specs
• GenieMat® RST15 Product Specs
• GenieMat® RST Product Brochure
• GenieMat® RST Simple Installation Manual
• GenieMat® RST Technical Installation Manual
• GenieMat® RST Technical Installation Manual For Vinyl Floor Coverings
• GenieMat® RST 3-Part Guide Spec