Commercial Roofing – Asphalt
Which Commercial Roofing system? Asphalt
To all intents and purposes mastic asphalt is a liquid applied system, the material being heated in a large cauldron until it becomes fluid at around 220 degrees centigrade. Therefore, it incorporates all the obvious disadvantages and risks that hot systems generate.
The same factor also detracts from it, many of the advantages usually associated with a liquid applied system because the heat makes it impossible to use in confined areas, such as under low lying plant or narrow gutters. Despite this asphalt is adaptable and can be used to form difficult details. Because it is unreinforced and does not cope well with movement, it is best used on stable substrates where there is unlikely to be any significant movement.
Mastic asphalt combines an aggregate within it, so it is ideal for use where there will be occasional access. However, in hot conditions it can become very soft and anything left lying on the surface will gradually sink into it and this can cause punctures. Therefore, contrary to popular belief mastic asphalt also requires protection or adaptation if it is to be trafficked regularly.
Mastic asphalt can be badly degraded by direct sunlight, ultraviolet light and heat. Therefore it is recommended that mastic asphalt is either covered or coated regularly with white solar reflective paint; generally every three or four years. Failure to do this will increase the risk of premature failure. Therefore this product comes with a maintenance issue.
Whilst older rock asphalt had a long life span the life span of mastic asphalt is in the region of 7.5 – 15 years, depending on exposure. It is also a relatively expensive option.
If you want more information on how a Mastic Asphalt system could suit your commercial roofing needs do not hesitate to get in touch with one of our surveyors, who can discuss any of your requirements.