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underblock HD rubber floor underlayment

UnderBlock™ HD Rubber Floor Underlayment

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In Stock. This product ships in 3-4 business days.

Get best-in-class IIC and STC ratings while laying most floorings directly on top. Preferred for multi-family and commercial!

Bulk discounts available. Save per roll at 5, 10 and 15 rolls.
$399.99
Covers 60.0 SF
$399.99

UnderBlock™ HD Rubber Flooring Underlayment

UnderBlock™ HD is the underlayment of choice for multi-family, hotels, and other large projects with high IIC requirements. Because most flooring (including many tiles) can be installed directly on top, save significant time during install while hitting 60+ IIC in many constructions. Contact us if you have questions about your specific assembly!

 

Features

  • Subflooring / underlayment for reducing impact noise, airborne noise, and vibration
  • 100% recycled rubber
  • Most flooring can lay directly on top (including tile)
  • Best solution for maximum IIC and STC
  • Commonly specified and used in multi-family
  • Easy roll out installation
  • Proudly made in the USA

 

 

Specs

 Dimensions   4’ x 15’ (3/8”), 4’ x 13’ (1/2”) 
 Thickness   3/8" or 1/2"
 Weight    100 lbs (3/8) or 120 lbs (1/2") 
 Color    Black 
 R-value   2 per inch

  

   

Resources 

 Spec Sheet 

 UnderBlock™ HD Product Sheet 
 Architect CSI Specs 

 UnderBlock™ HD CSI Spec 
 Install Guide 

 UnderBlock™ HD Install Guide 

 

 

Material Testing


For jobs with specific IIC requirements, contact us for to discuss your specific floor-ceiling assembly.

 

 

 Impact Insulation Class

 Roll Thickness   6" Concrete IIC 
 (LVT, No Ceiling) 		  8" Concrete IIC 
 (LVT, No Ceiling) 

 6" Concrete IIC 
 (Wood, No Ceiling) 

 8" Concrete IIC 
 (Wood, No Ceiling) 
3/8" 60 63 58 67
1/2" 61 64 65 68

 

 

Installation Instructions

  • Roll out UnderBlock™ HD to cover the subfloor. Adhesive is optional. UnderBlock™ HD is heavy and will not move around.
  • Use a metal straight edge to make any cuts with a sharp utility knife.
  • Leave a 1/8" gap between UnderBlock™ HD and any obstacles (walls, columns, posts, drains, pipes, etc). Fill this gap with acoustic sealant caulk.
  • For perimeter walls, you can run UnderBlock™ HD directly to or under the wall instead of leaving the 1/8" gap and sealing it.
  • Roll out the UnderBlock™ HD in rows, keeping the factory seams tight and flush. If the seams are flush, acoustic sealant is not needed. Joints and seams can be taped if desired.
  • Install your chosen flooring on top of UnderBlock™ HD rubber flooring underlayment. 

 

 

If you have any questions about your type of flooring for your project, call us and we can walk you through it!

  • Floating floors do not require additional adhesive. They just lay on top of UnderBlock™ HD.
  • Mechanically fastened floors (nail down) should have a subfloor glued to the top of UnderBlock™ HD. Use our recommended rubber adhesive when required.
  • Glue down floors should use whatever adhesive is recommended by the flooring manufacturer that is compatible with attaching to rubber.
  • When installing under carpet, UnderBlock™ HD should be cover the subfloor completely, leaving a 1/8" gap near obstacles to be filled with acoustical sealant. Tacking strips can be glued down to UnderBlock using our recommended rubber adhesive. Carpet padding is optional.

 

 

Common Product Uses

  • Multi-family condos, hotels, apartments, recording studios, conference rooms, commercial buildings, band rooms, houses of worship, theaters, schools, restaurants
  • UnderBlock HD delivers the best possible performance for a soundproof floor. It's the preferred choice for multi-family.
  • Meets building code for 6" or 8" concrete, even without a finished ceiling below.
  • Lay most flooring directly on top, including most tiles. 
  • Consider our standard sizes of Underblock™ Rubber Floor Underlayment