Modi 4.5 Slate is a plasticized bituminous roofing membrane consisting of a compound of distilled asphalt mixed with atactic polypropylene and various petrochemicals. When the asphalt is modified in this way, it imparts flexibility to the compound. The compound is bonded around a polyester core. The distinctive characteristics of the polyester core material include high tensil strength coupled with elongation capability, strength, toughness and excellent dimensional stability.


Modi 4.5 Slate is designed for use in most roofing and waterproofing situations, including new construction and reroofing.

Modi 4.5 SLATE is an APP torch-applied modified bitumen roofing membrane reinforced with a nonwoven polyester mat. Its finished surface is composed of authentic French slates available in two colors: white and gray.

INSTALLATION: Modi 4.5 Slate is easy to install using a proper Modi-Torch and Modi-Trowel.

WARRANTY: Modi 4.5 Slate carries our warranty from 10-20 years, depending upon the specification used.
Modi 4.5 Slates roofing products are intended for use by professional roofers only and are not intended for use by amateurs. Use of the torch and/or hot asphalt application methods represent potential fire/burn hazards and all appropriate safety measures and cautions should be taken. It is the sole responsibility of the applicator to exercise all necessary safety procedures.

Product Type APP Modified Bitumen
Application Method Torch
Reinforcement Nonwoven Polyester
Roll Weight (approx.) 98.2 lbs
Roll Length 10m (approx. 33')
Roll Width (approx. ± 1%) 1m (approx. 39')
Nominal Thichness (± 5%) 4.5mm (.177")
Surface Color White or Gray
Surface Finish Slate Flakes
Gross Area p/roll 107.6 sq.ft. (approx)
Net Coverage 95 sq.ft (approx.)
Rolls per Pallet 25
Weight per Pallet 2,500 lbs
Load Strain Properties Load (lbs/in)
Elong (%)
At 73.4° F MD 110, CD 75
50%, 50%
At 0° F MD 220, CD 150
21%, 24%
Tear Resistance (lbs) MD 105
CD 75
Moisture Content < 0.2%
Water Absortion < 0.5%
Low Temp. Flexibility 23° F
Low Temp. Flexibility (UNI-8202) 15° F
Dimensional Stability MD < 0.5%
CD < 0.2%
Heat Conditioning Physical property changes < 10% of original.
Accelerated Weathering Physical property changes < 10% of original.
Granular Embedment < 2G
Compound Stability No drop formation at 250° F