Flat Roof Insulation Standing Seam Multi-Ply Single Ply

ROCKWOOL Multifix™

Name: Multifix™
Brand: Rockwool

ROCKWOOL Multifix™ is a high-density insulation board with a mineral-coated fiberglass facer engineered for low-slope roof applications. Designed for use as the substrate for torched, hot mopped, self-adhered, cold-adhered, and liquid membrane systems, Multifix adds fire resistance, improved acoustics, and is dimensionally stable for long-term performance.

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Download datasheet Acoustic Solutions Guide

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Multifix is a dual-density, stone wool insulation board with a glass fiber coating for low slope roof applications

ROCKWOOL Multifix™ is the first stone wool insulation product with a mineral-coated fiberglass facer that is compatible with multiple attachment methods including:

torched
hot-mopped
self-adhered
cold-adhered
and liquid systems.

It can be used as thermal insulation in a low slope roof system, as well as an insulating coverboard over other insulation products. In these cases, it improves performance by regulating the temperature of the thermal insulation. In fact, just one layer improves the performance of the entire assembly.

ROCKWOOL Multifix™ features a dual density design that includes a higher-density top layer, providing strong point load resistance and effective load distribution to minimize puncture damage to the membrane – particularly during installation.

Build a better low slope roof with Multifix™

Roofing Accessory Materials

ROCKWOOL has a range of roofing accessory products available to provide a complete roof insulation assembly, to create a customized, high performing roofing system. These products include:

Toprock Tapered and Toprock Tapered Plus panels available as both unfaced and bitumen coated options
Toprock Flute Filler – N-Deck and B-Deck Flute Filler products available for metal deck roof acoustic applications
Toprock CANT Strips

These accessory products are available as part of a full ROCKWOOL roofing solution. Please contact your local ROCKWOOL roofing sales representative to learn more about ROCKWOOL stone wool roofing products.

Contact Roofing Support

Dave Lawlor

Canada and Mexico

dave.lawlor@rockwool.com

905-699-3861

Joseph Donnelly

United States

joe.donnelly@rockwool.com

484-426-7444

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Compliance

ASTM C726 - FM 4470

ASTM C726

Standard Specification for Mineral Fiber Roof Insulation Boards

FM 4470

Approval Standard for Single Ply, Polymer Modified Bitumen Sheet, Built-Up Roof and Liquid

Applied Roof Assemblies for use in Class 1 and Noncombustible Roof Deck Construction

NCC (Non Combustible Core) Rated Roof Insulation

Density

ASTM C303

ASTM C303	Top Layer - 13.75 lb/ft³ (220 kg/m³)
ASTM C303	Bottom Layer - 10 lb/ft³ (160 kg/m³) - for 2” (50.8mm) and 2.5” (63.5mm) thickness
ASTM C303	Bottom Layer - 9.36 lb/ft³ (150 kg/m³) - for >2.5” (63.5mm) thicknesses

Dimensional stability

ASTM C356 - ASTM D2126

ASTM C356

Linear Shrinkage - 0.71% @ 1200°F (650°C)

ASTM D2126

Linear Change 7 days @ -40°F (-40°C), ambient RH - 0.1%

Linear Change 7 days @ 200°F (93°C), ambient RH - 0.1%

Linear Change 7 days @ 158°F (70°C), 97% RH - 0.0%

Dimensions

48” x 48” (1219 mm x 1219 mm)

Thickness

Product available in 2” - 4” (50.8 mm - 101.6 mm) in 1/2” (12.7 mm) increments

Reaction to fire

ASTM E84 (UL 723)*** - CAN/ULC S102*** - CAN/ULC S114 - NFPA 276 - CAN/ULC S107-03 - CAN/ULC S126-06 - UL 790 (ASTM E108) - UL 263 (ASTM E119)

ASTM E84 (UL 723)***	Flame spread index = 0; Smoke developed index = 0
CAN/ULC S102***	Flame spread index = 0; Smoke developed index = 0
CAN/ULC S114	Determination of Non Combustibility of Building Materials - Non Combustible
NFPA 276 -	Standard Method of Fire Tests for Determining Heat Release Rate of Roofing Assemblies with Combustible Above Deck Roofing Components - Class 1
CAN/ULC S107-03	Fire Tests of Roof Coverings - Class A
CAN/ULC S126-06	Fire Spread under Roof Deck Assemblies - See ULC Directory
UL 790 (ASTM E108)	Standard Test Methods for Fire Tests of Roof Coverings - Class A
UL 263 (ASTM E119)	Fire Tests of Building Construction and Materials - See UL Directory

Thermal resistance

ASTM C518 (C177)

ASTM C518 (C177)	Mean Temperature	R-Value	RSI Value
	75°F (24°C)	3.8 hr.ft2.F/Btu	0.68 m2K/W
	25°F (-4°C)	4.3 hr.ft2.F/Btu	0.74 m2K/W
	40°F (4°C)	4.2 hr.ft2.F/Btu	0.72 m2K/W
	110°F (43°C)	3.6 hr.ft2.F/Btu	0.64 m2K/W

Acoustical Performance

ASTM C423 - ASTM E90

ASTM C423	Thickness	125 Hz	250 Hz	500 Hz	1000 Hz	2000 Hz	4000 Hz	NRC
2'	0.5	0.71	0.85	0.9	0.96	1.01	0.85

ASTM E90

Contact ROCKWOOL for STC rated assemblies

Reaction to moisture

ASTM C1104 - ASTM C209 - ASTM E96

ASTM C1104	Moisture Sorption - 0.15%
ASTM C209	Water Absorption - <1.0%
ASTM E96	Water Vapor Transmission, Desiccant Method - 2330 ng/Pa.s.m2 (41 perm)

Compressive strength

ASTM C165 - EN 12430

ASTM C165	Top Layer - 20psi (140kPa) @ 10%, 37psi (250kPa) @ 25%
EN 12430	Entire Board - 11psi (75kPa) @ 10%, 15psi (105kPa) @ 25%

Corrosion Resistance

ASTM C795 - ASTM C665

ASTM C795	Stress Corrosion Cracking Tendency of Austenitic Stainless Steel - Passed
ASTM C665	Corrosion of Steel - Passed

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ASTM C726

Standard Specification for Mineral Fiber Roof Insulation Boards

FM 4470

Approval Standard for Single Ply, Polymer Modified Bitumen Sheet, Built-Up Roof and Liquid

Applied Roof Assemblies for use in Class 1 and Noncombustible Roof Deck Construction

NCC (Non Combustible Core) Rated Roof Insulation

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ASTM C303	Top Layer - 13.75 lb/ft³ (220 kg/m³)
ASTM C303	Bottom Layer - 10 lb/ft³ (160 kg/m³) - for 2” (50.8mm) and 2.5” (63.5mm) thickness
ASTM C303	Bottom Layer - 9.36 lb/ft³ (150 kg/m³) - for >2.5” (63.5mm) thicknesses

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ASTM C356

Linear Shrinkage - 0.71% @ 1200°F (650°C)

ASTM D2126

Linear Change 7 days @ -40°F (-40°C), ambient RH - 0.1%

Linear Change 7 days @ 200°F (93°C), ambient RH - 0.1%

Linear Change 7 days @ 158°F (70°C), 97% RH - 0.0%

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ASTM E84 (UL 723)***	Flame spread index = 0; Smoke developed index = 0
CAN/ULC S102***	Flame spread index = 0; Smoke developed index = 0
CAN/ULC S114	Determination of Non Combustibility of Building Materials - Non Combustible
NFPA 276 -	Standard Method of Fire Tests for Determining Heat Release Rate of Roofing Assemblies with Combustible Above Deck Roofing Components - Class 1
CAN/ULC S107-03	Fire Tests of Roof Coverings - Class A
CAN/ULC S126-06	Fire Spread under Roof Deck Assemblies - See ULC Directory
UL 790 (ASTM E108)	Standard Test Methods for Fire Tests of Roof Coverings - Class A
UL 263 (ASTM E119)	Fire Tests of Building Construction and Materials - See UL Directory

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ASTM C518 (C177)	Mean Temperature	R-Value	RSI Value
	75°F (24°C)	3.8 hr.ft2.F/Btu	0.68 m2K/W
	25°F (-4°C)	4.3 hr.ft2.F/Btu	0.74 m2K/W
	40°F (4°C)	4.2 hr.ft2.F/Btu	0.72 m2K/W
	110°F (43°C)	3.6 hr.ft2.F/Btu	0.64 m2K/W