Brussels 18 20 february 2008 dissemination of information workshop 18.
Snow loading flat roof uk.
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.
Wind snow and rain.
A person needing to access the roof in order to repair items.
Flat roofs shall be designed to carry all imposed and dead loads acting on the structure of the roof.
Step 4 determine the flat roof snow load.
Other considerations for sloped roofs can be found throughout chapter 7 of asce 7 10.
Use this same calculation to find the total weight of snow on a flat roof.
Roof snow load calculation.
Snow loading on cladding we are fortunate in the uk to live in a country where winters are often relatively mild and severe snowfalls are rare.
The uniformly distributed snow loading on the roof is obtained by multiplying the ground snow load by the appropriate snow load shape coefficient see section 5 3 of bs en 1991 1 3 and annex b of bs en1991 1 3.
In our case let s assume that our structure has a flat roof roof slope 5.
Environmental loads such as snow water and wind loads should be calculated in accordance with bs en 1991.
The flat roof snow load is calculated using formula 7 3 1.
The scope of bs en 1991 1 3 is limited to snow loads only c in accordance with clause 3 3 2 1 of bs en 1991 1 1 roofs of buildings particularly domestic roofs where the allowed imposed loads cover maintenance only imposed loads need not be considered to act simultaneously with snow loads and or wind actions.
Flat roof structure.
For example using a 25 by 20 metre garden.
Paolo formichi university of pisa italy.
However when heavy snowfalls do occur there are often reports of damage to buildings in particular collapses of roofs and their supporting structures.
Estimate the total weight of snow in your garden by multiplying the size of the area in square metres by the snow load.
The loads weights to be supported are from various sources.
The snow load that is applied to our structure is not the ground snow load but in most cases the flat roof snow load.
The roof should be tied down to the structure to stop it from lifting in times of strong winds.
This would include tiles battens felt insulation etc.
The snow load on the roof is derived from the snow load on the ground multiplying by appropriate conversion factors shape thermal and exposure coefficients.
For ground snow loads greater than 20 pounds per square foot the roof load is equal to 70 of the product of the exposure thermal and importance factors the ground snow load and 20 pounds.
