Saturday 15 February 2014

Roof Supports and Water Proofing

When it is about designing a roofing system for your home or a building, then a lot of points are considered which includes the type of roofing used, the material used for roofing, water proofing, etc.  The major components of a roof include the beams, rafters, truss and purlins, etc. Every component has a special responsibility and one such component is the purlin. Purlins are used for supporting the roofing sheet or deck as well as stiffening the entire roof. They themselves require support also and this support is given by rafters. Another important point related to roofing is waterproofing. Here is where roof flashing comes into picture. Flashing is used for directing the flow of water around the openings of the roof. A run-down about roof Purlins and Roof flashing -

Roof Purlins – There are different types of purlins available in the market and they are categorized on the basis of their shape, the material used and their sizes. Earlier, wood was the material that was generally used for making purlins, but due to the huge cost and other disadvantages involved, the smarter alternative that has been in use for some time now is steel. Steel purlins and Roof purlin are very popular mostly in home roofing systems and also in industrial roofing systems. They are laid perpendicular to the I beams and in turn are supported by rafters, beams or even building walls. 


Purlin material & type - Steel purlins have many advantages over wood purlins. Wood is prone to termite, does not have resistance to fire, is heavy in weight and is costly too. While steel purlins are light in weight, steel is not prone to termites, has long life, is cheaper and has high resistance to fire also. Purlin designs include C Purlins, Z Purlins and U Purlins. The C purlins are Z Purlins are extensively used in construction and available in standard sizes.


Roof Flashing – Water seepage is a common problem in homes and buildings and is the cause of early deterioration of the structure and a lot of inconvenience and health problems also. It gives rise to moisture in the building damaging the reinforcement, creating mold problems and more. To avoid such problems proper roof flashing is very important. Flashing is useful in directing the water around the openings and is used in various stages of construction of the building. This includes flashing at ground level, that is above the ground level and just below the first course. Then the next stage is above the shelf and at lintel levels and also where the deck and the exterior stairs connect with the structure. Flashing is mainly used around the roofs to enhance water proofing.

Flashing material – There are various materials which are used for flashing and include plastics, sheet metal, stainless steel, copper and more. PVC flashing is considered to be the cheapest of all materials but the only disadvantage it has is, it wears and tears when directly exposed to sunlight. The best of all materials is sheet metal flashing as it is highly durable but again it is equally expensive also.

If the quality of the roofing and its components as well as flashing materials is good then, it will help in extending the life span of the structure and avoiding seepage problems for a long time. 




No comments:

Post a Comment