Roof trusses are prefabricated, triangular, wooden or metal structures that come factory-built according to your home's design specifications, so that they carry the weight of the roof onto external walls only. They have become popular compared to traditional rafters because of the accuracy and speed of construction. In addition, more complex roofs can be well-designed to bear the load and look attractive.
Extreme care must be taken during the design, construction and installation of roof trusses, or else one could risk having an unstable roof which presents its own set of perils. Read on to find what three things never to do when using trusses for your home or commercial building.
1. Making unauthorised changes
The adage "Measure twice, cut once" is well-known in construction circles, because it's important to get measurements right before cutting, which can't be undone. Prefab trusses are much more than just pieces of wood or metal stuck together; a lot of calculation goes into making trusses uniquely for each home so that the load is borne and transmitted uniformly to external walls.
Any unauthorised alterations once the trusses have been delivered interferes with the framework and may affect the integrity of your roof. Always contact your manufacturer or supplier if there's anything amiss with the construction or installation of trusses. They should also be notified if alterations are made to the site so that this is accounted for during truss construction.
2. Not following installation instructions
Similarly, trusses come numbered to indicate where they should sit on your roof, and the integrity of the whole depends on following this scheme. Every small detail should be observed according to the manufacturer's recommendations, including the type and size of bolts and screws and where to place them. Trusses must be appropriately braced before roofing sheets or shingles are placed on them.
3. Changing roofing materials
Roofing materials are not created equal; asphalt roofs may be heavier than metal roofs, and the latter also differ in weight according to the metal used in construction. Similarly, trusses for horizontal shingles aren't constructed the same way as vertical sheets. Therefore, once trusses are made to carry a certain type of roof, you should not change to a different material. While the weight difference of one shingle/sheet may be small, this difference adds up when the roof is considered in its entirety. It is advisable to indicate your intended roofing material in your specification sheet so that it is factored in during construction.