Rain Loading Configuration On A Roof

2014 fbc building 5 th edition 16 structural design 1611 rain loads 1611 1 design rain loads jump to full code chapter each portion of a roof shall be designed to sustain the load of rainwater that will accumulate on it if the primary drainage system for that portion is blocked plus the uniform load caused by water that rises above the inlet of the secondary drainage system at its design flow.

Rain loading configuration on a roof.

Until recently floor live load roof live load roof snow load wind load earthquake design data and flood loads were required to be listed on the construction documents. In northern mississippi it may be rain. The key to managing rain loads in buildings is roof drainage including a primary drainage system and a secondary drainage system which is set at an elevation higher than the primary system to drain any water that builds up after the lower system is blocked or not working. The architect has decided to use 6 in.

Determine the design rain load on the roof of a building that is 250 ft wide and 500 ft long. D s depth of water on undeflected roof up to the inlet of the secondary drainage system. Should your roof installation have to be delayed due to poor weather be patient. During a roof installation there are several steps to ensure that your home s interior is never exposed.

Asce 7 says that the rain load is 5 2psf in h s h d. While the completed shingles may not be in place during an unpredicted rainstorm there should be a protective layer on your roof that keeps rain from getting in. Sloped or not each segment of the roof shall be capable to carry the loading created due to blockage of the primary roof drainage system of that segment plus the load caused by water that rises above the inlet of the secondary drainage system at its design flow rate. Note that although rain loads are covered in ibc section 1611 they were not required to be listed on the construction documents.

The secondary drains are located 1 5 in. Depending upon the location one of these will be the controlling roof live load. The accumulation of water caused by the deflection of the roof structure is called ponding and as it results in added load it can lead to roof instability. This is highly regional as weights of snow for example range from 10 to 300 pounds per square foot based on moisture and volume of the snow.

Diameter drains spaced uniformly along the long sides of the building at 40 ft intervals for the secondary drainage system. This is all of the natural stresses imposed upon a roof such as snow loads rain loads and wind loads. The event that shall be considered is an intense short duration rainfall. For a building in northern vermont snow is likely the controlling roof live load.

D h additional depth of water above the secondary inlet undeflected roof at its design flow hydraulic head it appears as though this is applied as a uniform load when viewing the examples in the commentary. During its lifetime a building roof is subjected to a number of different structural loads roof dead loads and roof live loads principally snow wind and rain.