It is not unusual to experience leakages on brand new roofs irrespective of roofing products used. In most cases, the leading cause for the leakages is omission of a roof underlay or the use of APP membranes as an underlay which does not self-seal when nailed.

A roof underlay is one of the most important components that go into your roof, it is a thin water-resistant membrane with a self-locking system that helps to prevent roof leakages. When working on a shingles roof, the roof underlay goes directly on the decking material used such as the OSB boards or on T&G. If working on other roofing materials it is fixed directly below the roofing product of choice.

There are three types of roof underlay

Types of Roof Underlay

Synthetic roof underlays

This underlay is reinforced with fiberglass. Hence, it is watertight, tear-resistant, lightweight and high strength. It is also wrinkle-free and resistant to fungus. Many roofing experts prefer it to the rest of underlays. , It is also cost efficient with a square meter costing between Khs. 200-300 VAT inclusive. The leading brand in this type of underlay is Armourbase eco

Rubber based underlays

This underlay is made of asphalt and rubber polymers making it waterproof and therefore, more expensive. It has an adhesive on one side. The adhesive is formulated to withstand extreme cold and extreme heat. It is also relatively heavier compared to the synthetic underlay.

Asphalt based underlays

It is also called tar or felt paper. It is commonly used in residential, steep-slope roofs. It is made of fiberglass substrate and/or blends of cellulose, bitumen or asphalt. This type of underlay is water-resistant, but not waterproof.

The Armourbase ECO Roof Underlay

This is the leading brand among the Synthetic roof underlays. It is made from polyester and reinforced with fiberglass. The Armourbase ECO Roof Underlay is self-locking which makes is water-resistant. The armourbase eco can be fixed on pitched roofs whose slope is less than 20 degrees. The application method is done through nailing using special galvanized nails.

Benefits of Armourbase ECO Roof Underlay

• The armourbase eco roof underlay is light in weight, a roll of 50 meters weighing 19 Kgs unlike conventional underlays that way between 30-50 kg for a 10-meter roll.
• They are non-skid making roof walkability safe and installation process more efficient for the technicians
• They are quite economical, the price range of Ksh. 250-300 / sq.mt compared to other membranes cost of Ksh. 400-500/ sq.mt
• The fiberglass and polyester base makes them resistant to fungi and mold attacks
• They are waterproof, hence protect the decking from damage.
• They are UV resistant, this means that they can be left exposed on the roof for a period of 6-8 months without cause for alarm in any weather condition.

Roofing 1 on 1

Would you like to know more about installing Polycarbonate Sheets?

We conduct a FREE program ‘’Roofing 1 on 1’’ at our REXE Showroom on Taranaki Court, off Chania Avenue, Kilimani, and we would love it if you could visit us.

Feel free to Get in Touch with us for more information on our Roofing materials and products. We supply and install APP Waterproofing membrane, Roofing Shingles and Stone Coated Roofing Tiles, among other Roofing Boards and accessories.