The Content Of The Article:
The green roofs have a lot of advantages, besides being beautiful and providing a bit more nature in the middle of the city.
This helps to make the roof skin last longer, because the roof is exposed to significantly lower temperature fluctuations. On the planted roof one can welcome entire animal and plant companies, which otherwise have no basis of livelihood in the city.
Construction of a roof greening: lay root protection sheet
There are really enough arguments for green roofs. That's why many homeowners today want to green a roof on their property. In order for all advantages of the green roof to come to fruition, the structure must be correct, and this crucially depends on the correct application of the root protection sheet:
- The structure of the green roof is carried out according to a specific scheme, which provides more functional layers for the plant layers compared to the usual flat roofs layer structure. The first crucial functional layer, which distinguishes the green roof from the usual flat roof, is the root protection membrane, which is applied directly over the supporting structure and thermal insulation.
- If a roof skin lives longer under a green roof, one of the reasons is that the roof skin and the roof seal are permanently protected by the root protection membrane from damage by plant roots. Therefore, the root protection membrane must be laid so carefully and professionally that even the most persistent root can not find access.
Which root protection is suitable?
Root protectors are made of different plastics, eg. As of soft PVC, polyethylene or modern synthetic rubber EPDM. These plastic sheets are available in thicknesses of 0.8 and 1.5 mm. It is important, of course, that the plastic material is root-resistant, and the manufacturers carry out the verification by carrying out and documenting a test according to FLL procedures.
In addition, you should insist that the provider has at least ten years of experience with the root protection membrane in practice, because as long as your root protection should be in any case. You should also be assured by the supplier that the root protection sheet does not contain any substances harmful to the environment or plants.
Further steps for processing the protective film
- The root protection sheet should be welded to the roof. Depending on the material is cold-welded (for example, PVC sheets with solvent welding) or hot-welded (PE sheets, for example). Sometimes it is recommended to lay the root protection sheet without welding with overlap. This is usually not advantageous, if under a Wurzelschutzbahn only the slightest moisture or nutrients can be found, the plant roots will go there over long distances. Particularly talented in this regard are plants with long root shoots and high root pressure.
If you want to plant couch grass, horsetail, tadpole and similar fast rooting on the roof, fabric reinforced sheets should even be sealed with an additional seam sealer to prevent the roots from finding any open spots or capillaries. Most films designed as root protection sheets are UV-resistant; if this is not the case, the film must also be protected from too much sunlight at the edges.
What is to be considered?
If non-woven foils are mechanically fastened, the length of the fixings may change with temperature and age, then you will need to re-attach torn wall connections. Another weak point of a root protection membrane is that it may contract. Then it can be e.g. under a zinc cover, in which area soil and leaves can accumulate, which form a breeding ground for flying seeds. The roof seal is then unprotected in this area, the roots can penetrate unhindered, damage to the building can be the result. Occasional control of the integrity of the root protection sheet should therefore be routine.
- Instead of a root protection membrane, a root-resistant roof seal can also be applied. Here, too, a wide variety of materials can be used: PVC, bitumen, polymer bitumen, EPDM, mastic asphalt, ECB, and others. The advantage of a root-resistant roof gaskets is that it eliminates the need for an over-laid root protector, which can make the entire roof structure cheaper, depends on the prices of the individual films.Even with a root-resistant roof seal, you should obtain the certificate of an FLL test procedure and proof of at least 10 years of use.
The careful laying of the root protection membrane is also important because it is followed by several layers: the separation and protection layer, the drainage layer, the filter layer, the vegetation layer and the planting. For this reason, the root protection sheet should never be restricted to the vegetation area in used areas, but should form a self-contained, watertight tank on the entire roof.