Roofing felt
Roofing felt (also tar paper ) is cardboard soaked with bitumen that serves as a moisture barrier in buildings. Often, coarse-grained sand , fine gravel or slivers of slate are rolled into the roofing felt in order to achieve greater abrasion resistance and UV resistance . In residential and commercial buildings, roofing felt is often used as a second roof skin (underlay) under the roof tiles . In simple buildings such as gazebos , tool sheds and the like, roofing felt is often the sole roof covering, the lifespan of which is shorter than that of a tile or metal roof.
Roofing felt is a colloquial generic term for two types of waterproofing membrane:
-
Roofing membranes have a lower weight per unit area and are not suitable for being hot-welded to the substrate without the addition of liquid bitumen, because the bitumen content is too low to ensure that the membrane is securely embedded and later sealed. They are on one side, but mostly on both sides with sand or slate flakes.
Roof waterproofing membranes are either nailed or glued using bitumen adhesive, or laid loosely and secured by ballast. Alternatively, cold self-adhesive bitumen sheets are available. - Bitumen welding sheets are significantly thicker and are not laid loosely, but welded together by flame cutting. These are therefore only sanded or slated on one side and coated with talc or foil on the side to be welded. Bitumen welding sheets can be used to seal against standing and pressing water.
use
Roofing felt is laid across the roof pitch and overlapping at the longitudinal and transverse joints and attached to the roof boarding with roofing felt nails or staples .
As die-cut Preolit shingles , they were a roof covering typically used in the GDR for many years, which was used instead of roof tiles or slate. These were soaked in coal tar in the early 1970s , which turned out to be effective against moisture, but also to be carcinogenic and therefore extremely dangerous to health and the environment. The tar-containing roofing felt is no longer produced after an EU-wide ban on use.
invention
In 1842, the Neustrelitz master builder Friedrich Wilhelm Buttel published the monograph Practical Experience on Dorn's Roofs, along with a detailed description, cost calculation and drawing of such constructions, which give them greater duration and impermeability, and an appendix on flat roofs in economic buildings . In it he first described the tarred roofing felt for covering classicist flat roofs and can therefore be regarded as its inventor.
materials
Roofing felt usually contains a layer of fiberglass , polyester or jute fabric .
Tar roofing felt was used until the early 1970s and was soaked in coal tar . Coal tar is carcinogenic due to its ingredients such as polycyclic aromatic hydrocarbons (e.g. naphthalene , anthracene or benzopyrene ). For this reason and because of the ecological pollution, coal tar has not been used in roofing felt for decades and is prohibited. Tar roof sheeting is no longer manufactured in Europe.
Bitumen or polymer bitumen has been used since the early 1970s . Since then, roofing membranes have been completely free of tar. In the production of bitumen roofing membranes, however, lighter hydrocarbons with up to 20 carbon atoms are emitted.
disposal
Even today you can still find roofs of old industrial buildings or empty warehouses all over the world, which are covered with tar-soaked roofing membranes. Due to the various, partly toxic substances, bituminous, but above all tar-containing roofing felt is a hazardous waste and requires professional disposal.
literature
- Friedrich Wilhelm Buttel: Practical experiences about Dornsche roofs together with a detailed description, cost calculation and drawing of such constructions, which give them greater duration and tightness, and an appendix about the flat roofs in economical buildings. Barnewitz, Neubrandenburg 1842.
- E. Luhmann, R. Eßlinger: The manufacture of the roofing felt and the paint for cardboard roofs. 3. Edition. Hartleben, Vienna 1929 ( chemical-technical library . Volume 106).
- Bernd Binné u. a .: Technical rules for the planning and execution of seals with polymer bitumen and bitumen sheeting, abc of bitumen sheeting, 3rd, revised edition, vdd Industrieverband Bitumen-Dach- und Dichtungsbahnen, Frankfurt am Main 2002, ISBN 978-3-9801831-4 -7
Web links
Individual evidence
- ↑ Roof waterproofing - have roofing felt properly laid: materials, processing & costs in comparison , Dachdecker.de, September 2, 2011, accessed in November 2016.
- ^ Karl Bergmann, Walter Pieczonka, Werner Schneider: Hydrocarbon emissions in the production of bitumen roofing membranes . Dust - cleanliness. Luft , 49 (1989) No. 1, pp. 25-28.
- ^ Disposal of roofing felt ( Memento from November 22, 2013 in the Internet Archive )