Heat-sealable felt

What is the difference between heat-sealable roofing felt and traditional cold felt?

Traditional roofing felt is attached using bituminous adhesive or mechanically with papiak nails. Thermally weldable felt is heated with a burner. The heated bitumen layer sticks to the insulated substrate.

Heat-sealable felts are thicker and more durable than ordinary felts. The exception are self-adhesive roofing felts, which are the first layer when insulating the roof with hard Styrofoam. Self-adhesive felt is also called self-vulcanizing felt.

What are the average costs of purchasing and installing heat-sealable felt per square meter?

The price of thermo-weldable felt is from EUR 9 per m2 to EUR 25 per m2. Of course, there are also special-purpose roofing felts, such as bridge felt or felt adapted to the so-called green roof. These roofing felts are about 30% more expensive than their heat-sealable counterparts.

Are there different types of thermally weldable felt for different types of roofs?

We distinguish thermally weldable roofing felts for insulating standard roofs. Usually, roofing felt with a thickness of 5.2 mm is purchased. It is marked with the symbol S52 PYE 250 SBS.

Roof felt for green roofs is a roofing felt with increased durability. This felt has been adapted to insulate terraces and roofs where, for example, lawns are grown.

The bridge felt is at least 5.6 mm thick. It is an additionally reinforced roofing felt, adapted to withstand high stresses caused by the movement of machines. It is one of the strongest heat-sealable felts on the market.

How long is the warranty for heat-sealable felt and what conditions must be met for it to be valid?

The warranty for the felt is specified in the product data sheet and varies depending on the product. Vinyl felt sheets not marked V60 do not have a one-year warranty. Modified roofing felts have a warranty of 2 to 25 years. The length of the warranty period includes the manufacturer's warranty and the construction company's warranty.

The manufacturer's warranty is not recognized if the specialist has not completed the manufacturer's training and if he has not issued an invoice and a written warranty for his services.

What tools and materials are needed for proper installation of heat-sealable felt?

A long lance torch, propane cylinder gas and insulating gloves are required. Additionally, professionals use a long hook to unroll the felt and a steel roller to press the felt at the strip joints.

Is the thermally weldable felt resistant to UV rays and extreme weather conditions?

The felt is somewhat resistant to UV. It should be mentioned that sunlight is the main cause of aging of the felt, so it is worth preserving it with bitumen and sprinkling with fine sand, preferably every 5 years.

The felt is resistant to low temperatures and even remains flexible even at negative temperatures. The yield strengths differ for roofing sheets and are described in detail in the technical data sheet of a specific model.

Can I install the thermal felt on my own or do I need a specialist team?

Yes, it's not difficult if you know a few rules. I invite you to read our guide on how to install thermally weldable felt.

What are the recommendations for manufacturers of heat-sealable felt known for high quality?

Manufacturers recommend tearing off the old surface and placing two layers of roofing felt on a concrete surface primed with Abizol. The first roofing felt should be the underlay felt and the second layer should be the top covering felt.

Is thermal felt felt ecological and can it be recycled after its service life?

Roof felt is a petroleum-based product, therefore it is harmful to the environment. Used roofing felt is disposed of at appropriate facilities. Disposing of roofing felt is expensive. These facilities process roofing felt into material used to build asphalt roads.