Snow Load And Tensile Roof

Edwin nagy at the university of maine department of civil and environmental engineering.

Snow load and tensile roof.

It is perhaps the least understood of the resisting forces and could increase significantly the snow load on a roof. The purpose of this web site is to provide ground snow load analysis information and data gathered from all 50 states. The flat roof snow load is calculated using formula 7 3 1. S equals the depth in inches of the snow on your roof and p represents the pounds per square foot your roof is supporting.

The snow load that is applied to our structure is not the ground snow load but in most cases the flat roof snow load. It is a sign that the roof is adequately insulated and vented. The roof or the entire structure can fail if the snow load exceeds the weight the building was designed to shoulder. Other considerations for sloped roofs can be found throughout chapter 7 of asce 7 10.

In our case let s assume that our structure has a flat roof roof slope 5. This issue of live load vs. Victor staley a building official in the town of brewster mass responds. Unlike roof snow loads roof snow depths were not constantly measured in mccall.

Modern buildings are designed with snow load in mind said dr. In fact having a reasonable depth layer of snow on a roof is a good thing as long as the roof is designed to handle the weight. Your equation for determining snow load s x 1 25 p is fairly straightforward math. The roof shall be designed for the live load indicated in table r301 6 or the snow load indicated.

Or if the building was poorly designed or constructed. How snow load can damage your buildings. Purpose of this web site. If unbalanced snow loading isn t required or specified the truss designer may enter the 25 psf snow load as a top chord live load tcll set the load duration factor to 1 15 for snow and turn snow loading off completely.

Each state has a listing of building code and applicable guidelines for snow loads as well as details about where the snow load information may be found or purchased. It also provides an additional level of insulation and protects the roofing material from sun exposure which is your roof s worst enemy. Ground snow load might seem somewhat confusing until you read the basic premise that is identified in irc section r301 6 which states. Or the 25 psf snow load could be entered as a roof snow load with the unbalanced snow loading option turned off.

Shed structures will not exhibit this tensile force. The tensile force involves the bridging of snow across the ridge taylor 1983. If you live in the us our snow load calculator compares the total weight on your roof with the permissible load calculated according to the standards issued by the american society of civil engineers regarding the minimum design loads for buildings and other structures asce7 16.