18th May 2024

Flat Roof Insulation

A Flat is in general referred to the roofing element when it’s slop is less than 10°. Sometimes these are also defined as “Low Slope Roofs”. These can be constructed traditionally with concrete as well modern sheet metal roof construction which are also known as low-Pitched Roofing.

Insulation is now an integral part of the Flat roofing system to make them thermally efficient and insulation from the top is covered by a membrane to make it weather tight to avoid any water ingress into the system.

SRW Rockwool

SRW offers High Density Rigid Rockwool Boards specially designed to achieve very high compression strength to provide adequate compression to foot traffic load. SRWF Roofing Board Insulation are manufactured in compliance to the requirement of ASTM C 726, ASTM C612 & EN 13162.

SRWF Rockwool Board are compatible with almost all type of roofing systems Like Fully Bonded, Partially bonded, Mechanically fastened single ply roofing membrane, EPDM, torch applied Bituminous membrane etc.

Roof Insulation can be designed in multiple layers in combination with variable densities with lower density bottom layer and high density top layer suitable to provide high compression strength to the Roofing System.

Consult SRWF Technical team for more information on the Roofing Insulation system.

Rockwool Benefits

  • Especially designed product for higher compressive strength requirement.
  • Excellent Fire Safety
  • Excellent Thermal Performance
  • Acoustically Effective
  • Non-Combustible
  • Fire Resistant
  • “zero” Flame Spread Index
  • “zero” smoke Developed Index
  • No Toxic smoke or Gases
  • Chemically inert

Technical Parameters




Compliance Standard

Thermal Conductivity


0.033 -0.034

ASTM C 177 / ASTM C 518



128 - 200

ASTM C 303



50 - 150


Compressive Strength


45- 85

ASTM C 165

Surface Burning Characteristics

•Flame Spread Index
•Smoke Developed Index



ASTM E 84 / UL 723

Moisture Absorption



ASTM C 1104

Water Absorption



BS EN 1609