Bituminous shingles are a roof covering consisting of individual overlapping elements made of bitumen-impregnated or soaked felt or a fiberglass mat. Bituminous shingles are covered with bitumen on both sides and are usually provided with a protective layer of mineral granules on the top.
The elements are roughly rectangular and are laid in rows. A single layer can be used for a waterproof finish. The bituminous shingles are laid from bottom to top, with the top row partially overlapping the bottom row of shingles, without continuous seams between the overlapping rows. Shingles must be laid on a level, load-bearing substrate.
If the shingles are in good technical condition, they can still last for years. A precise expected lifespan is difficult to predict and also depends on various factors, such as weather conditions. If the shingles are in moderate condition, the bitumen can last another 2 to 5 years. If the shingles are in poor condition, the covering should be replaced immediately. The risk of leakage is very real, which will cause further (consequential) damage.
If the roof has a gravel layer: roof gravel is applied to roofs as ballast. If the roof is covered with coarse gravel, you must regularly remove moss and algae growth. Maintain a layer of coarse gravel of at least 3 cm. This will prevent it from blowing away and sinking into the subsoil.
In the past, mastic was used as a roofing material for flat roofs. Mastic was a kind of tar-like roofing material. Therefore, there weren't many other solutions available for applying mastic roofing to a flat roof. Mastic had advantages but also many disadvantages. In the summer, the mastic became semi-liquid, and in the winter, it became brittle and vulnerable. Mastic roofing was difficult to repair, and combined with the first emerging roof insulation, it was a particularly bad combination. When it later became apparent that mastic was also harmful to health, the use and installation of mastic roofs was discontinued in the late 1970s. However, mastic roofs are still regularly found in the Netherlands, often in an advanced state of decomposition.
The cost of a building inspection (up to 250 m²) is only €489 including VAT. We'll conduct a comprehensive building inspection and you'll receive a building report. Do you have any questions? We're happy to help and can schedule an appointment with an expert inspector right away if you wish!
