Residential flooring


The unique design of the Granab systems – with components made from inorganic materials, steel girders, dampening elements and adjustment screws of various lengths – permits installation in many project types and entails considerable benefits to houses, apartments and common areas through its innovative design, durability and ease of installation.


Impact and airborne sound insulation

Granab subfloors are ideal for residential construction offering a range of sound insulation qualities and performance from compliant to exceeding  the requirements of Approved Document Part E.

Modern apartment interior built using Granab subfloor system


Building Regulations
The Building Regulations approved document Part E requires the following performance values:


Airborne sound insulation in accordance with Building Regulations Part E

Permitted values between spaces Rw (dB)
Type of space Airborne Impact
Purpose built dwelling-houses and flats 45dB 62dB
Dwelling-houses and flats formed by material change of use 43dB 64dB
Purpose built rooms for residential purposes 45dB 62dB
Rooms for residential purposes formed by material change of use 43dB 64dB
Labratory values 40dB
Granab values *58dB 51dB
*Granab system height 70mm Incl. floor covering laid on 185mm hollowcore


Key residential benefits

  • Excellent airborne and impact sound insulation
  • Height adjustable screw legs from 30 to 420mm
  • Creates a service void for utilities and ventilation
  • Suitable to facilitate most under floor heating systems
  • Crates a creak free and comfortable floor to walk on
  • Low weight at 5kg/m2 compared to screed at 200kg/m2
  • Fast, accurate and easy installation

Granab flooring system 3000N spacing guide

System 3000N standard spacing guide for main living areas.

Granab flooring system 7000n girder spacing guide

System 7000N standard spacing guide for main living areas.


Recommended c/c spacings for girders and support blocks

  1. Rooms in dwellings, hotels, hospital rooms and staff rooms, c/c distance girders (sections), 600 mm.
  2. Assembly rooms such as classrooms, rooms in childcare centres, lecture halls, office rooms, premises for restaurants, cafés and dining halls, c/c distance girders (sections), 400 mm.
  3. Open areas in libraries, spaces with fixed seating such as in churches, theatres and cinemas, c/c distance girders (sections), 400 mm.
  4. Spaces without fixed seating in churches, concert halls, theatres, cinemas, museums, exhibition halls, retail areas in department stores and shops, gyms, sports centres, dance halls, corridors in schools, etc., c/c distance girders (sections), 300 mm.