Ground snow load to which several modification factors are applied.
Snow load on roof trusses.
A live load is a temporary load that puts stress on the structure.
To figure out the load on your roof take the depth of snow in feet and multiply it by the weight of a cubic foot of snow.
The snow load calculations provided by this online tool are for educational and illustrative purposes only.
Snow loads are influenced by elevation general weather and moisture patterns slope direction exposure roof or trail bridge configuration and wind direction and severity.
Dol can play a part in some snow areas where the building official bo has made the determination snow will remain upon the roof for extended time periods.
The current snow load criteria irc 2012 2015 r301 2 3 irc 2012 2015 figure r301 2 5 ibc 2012 2015 1608 begins with a base value i e.
The truss could be designed based on the assumption that the 25 psf roof snow load is a factored ground snow load in which case a ground snow load is back calculated using asce 7 based on the specified roof snow load pg 25 psf therein lies the problem with specifying only a roof snow load.
If the snow weighs 10 pounds per cubic foot and there are 1 5 feet on the roof each square foot of the roof is getting 15 pounds of pressure.
Live loads include wind precipitation foot traffic and all other weight that comes and goes.
Engineered truss drawings should be obtained for specific site locations incorporating specific snow load wind speed eave wall height building length and importance factor use of building.
Actual load due to snow will depend upon the shape of the roof and its capacity to retain the snow and each case shall be treated on its own merits.
Medeek design assumes no liability or loss for any designs presented and does not guarantee fitness for use.
These factors account for variables such as site exposure building importance roof slope and the thermal properties of the roof.
If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow.
Live loads and dead loads.
Lengthand widthof your roof.
Trusses are designed to carry two types of loads.
A dead load is carried constantly by the truss.
Overestimation of snow loads can unnecessarily increase the cost of construction.
To calculate the weight of snow on a roof use the first two sections of our snow load calculator.
The top chord live load tcll of any roof trusses will be the greater of pr or lr.
You can enter these values in any units you d like including meters and feet.
Duration of load dol for snow is typically 1 15.
The information provided here is not intended to replace truss drawings.
