Replacing roofing membrane

Roof leather has a hard time in the Netherlands. On flat roofs, leaves and rainwater easily remain and in summer the bright sun causes the roofing leather to dry out. To prevent leaks, it is wise to replace the roofing leather every 30 years. In this article you will read more about the costs of roofing replacement, the procedure and tips for finding the best roofer.

What does it cost to replace roofing membrane?

Roofing leather, or bitumen roofing, is one of the cheapest types of roofing material. This is because the material is relatively cheap and the new layer of roofing is easy to lay. With roofing leather, you also have the choice of laying a new layer of roofing over the old one. Check out this price chart for the cost of roofing on a flat roof.

Advantages of roofing over old roofing

• Costlier:Applying new roofing over the old layeris cheaper than removing the old covering first. The roofer will have the job done faster, saving you on the hourly wage.
• Extra insulation:Because the old roofing sheet is left in place, it provides extra insulation.

What is roofing leather?

Roofing leather, or bitumen, is a product derived from crude oil. After petrol and diesel, among others, have been removed from the petroleum, tar remains. This tar, or roofing leather, is a rock-solid form of roofing material. Roofing tar is the most commonly used form of roofing material on Dutch flat roofs.

How does a roofer replace roofing leather?

Roofers replace roofing leather when the roof structure is dry, and the thermometer indicates at least 5 ℃. This ensures that the new layer of roofing leather sticks well to the old layer. If the old layer is too damaged to serve as an underlayment, the roofer will remove it first. Roofing companies proceed as follows when installing roofing leather:

Step 1 – The underlayment

Before the roofer applies the bitumen layer, the roof will first receive an underlayment. This layer ensures a completely waterproof roof. The roofer starts by gluing the underlay at the eaves. Once the eaves are covered with the underlay, the roof surface is covered. The underlayment on the roof surface is also glued. The roofer keeps an average overlap of 10 cm. This means that each roll of roofing membrane lies 10 cm over the adjacent roll. When the entire roof is covered with the underlay, the roofer nails the underlay with a zigzag pattern. For a watertight seal, the roofer glues the seams.

Step 2 – Roof trims

After the roof is covered with the underlay, the roof trims are placed. The roof trim provides a nice finish to the eaves.

Stage 3 – The top layer

The roofer lays the roofing leather in the same direction as the underlayment. Again, the roofer uses a 10-cm overlap. Roofers use a torch to apply the roofing membrane.

Roofing leather burning:The roofer heats the roll using a propane torch, this makes the roofing leather stick. The roofer unrolls the heated roofing leather and rolls on the roofing. This gives the roof a watertight seal. Are you planning to lay the roofing on the flat roof yourself? Be aware that heating roofing tar is a very dangerous and tricky job. This is because the roofing sheet must not burn.

Step 4 – Roofing leather over the roof trims

For a complete seal, the roofer lays the roofing leather over the previously installed roof trims. To do this, the roofer uses a special sealant.

Durability of roofing leather

Roofing leather has an average lifespan of 30 years. It is even possible for roofing leather to remain waterproof for up to 40 years. Factors such as sunlight and weather conditions have a major impact on the lifespan of roofing leather. Rainwater, and possibly leaves and branches, remain on the roof. In addition, UV rays and temperature fluctuations cause the roofing sheet to dry out over the years.

Tips for replacing roofing sheet

If the roofing sheet has been applied properly, you will not have to worry about it for decades. To make sure you get a perfectly watertight roof and the best value for money, here are three tips.

Certification

Please check the roofer’s website to see what quality marks they have. Many roofers are members of VEBIDAK. Roofers affiliated with this quality mark have trained staff and are insured against any damage.

Kwantum discount

Please ask neighbours if they too would like to replace their flat roof with roofing membrane. If you combine several projects, it is possible to receive a volume discount from the roofer.

Compare quotes

By requesting several quotes, you will get a good idea of the different costs for replacing roofing leather. See which roofer offers the best value for money. Also check the quality marks, guarantee periods and delivery time of the roofer in order to make the best choice.