Roof Weight Allowed

Roof structure and load bearing capacity.

Roof weight allowed.

The owner s manual for your car will have a section on the maximum weight that can be carried on the roof. A roof is composed mainly of two parts the cladding or external material and the internal support structure which holds it up. Ballast stone fractures and gets sharper over time which can puncture the membrane. A clay tiled roof may have a dead load.

The dead load of a typical asphalt shingled wood framed roof is about 15 pounds per square foot. But on an average the rv roof should be able to handle one persons weight easily. If the bottom chord of a roof truss functions as a floor joist such as in an attic room it carries a live load that also varies by use but a typical live floor load for a residential space is about 40 pounds per square foot. Ballast stone traps a lot of dirt making patching difficult.

A normal human average weight of around 250 lbs to 280 lbs should be the limit for the roof. The amount of weight the internal support structure can carry without the roof collapsing can be described as its load bearing capacity. The load increases with the use of heavier roofing material. What weight can the rv roof handle.

Dead load weight of roof trusses top chord bottom chord webs weight per lineal foot plf 2x4 2x4 2x4 4 3 2x4 2x8 2x4 5 6 2x6 2x4 2x4 4 8 2x6 2x6 2x4 5 5 2x6 2x6 2x6 6 2 2x6 2x8 2x4 5 9 2x6 2x10 2x4 6 6 2x6 2x10 2x6 7 2 2x8 2x8 2x4 6 6 2x8 2x8 2x6 7 2 2x8 2x10 2x8 8 4 dead load weight of floor trusses depth in inches top chord bottom chord. Adds a lot of weight to the roof system typically 10 15 pounds per square feet. We often find the car will have a lower weight limit than the roof bars so it s important to check and never exceed whichever is the lower of the two.