The loads weights to be supported are from various sources.
Roof snow load map uk.
Part 3 is based on work carried out in the 1970s.
A european research group was formed to produce a unified snow map for europe.
Wind snow and rain.
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.
Measure the horizontal distance from eaves to the ridge the point where the roof is tallest and record the result labelled as run for example consider a roof with a run of 12 2 metres 40 feet.
This paper discusses the extreme value analyses performed on uk and eire meteorological data the.
Obtain the recorded snow load the maximum load expected to accumulate on the ground for your area.
Kn m 2 s o the site snow load on the ground at the relevant site determined from a the altitude of the site kn m2 s d is the snow load on the roof kn m 2 1 3 approach.
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 flat roof snow load is calculated using formula 7 3 1.
The roof should be tied down to the structure to stop it from lifting in times of strong winds.
Unfortunately we regularly inspect buildings new and old in the area with roof frames having a safe loading capacity of below 20 psf.
During the development of the eurocodes the snow loads given by the national standards were reviewed.
In our case let s assume that our structure has a flat roof roof slope 5.
That means properly built buildings since 2002 should be safe to support about 7 feet of dry powder.
Other considerations for sloped roofs can be found throughout chapter 7 of asce 7 10.
The approach will be as follows.
Use our massachusetts ground snow loads map to easily determine the ground snow load massachusetts state building code.
The current 2000 ground snow loading map for the uk in bs 6399.
S is the snow load on the roof kn m2 b bs 6399 3.
When the imposed load is considered as an accompanying action in accordance with en 1990 only one of the two factors ψ en 1990 table a1 1 and αn 6 3 1 2 11 shall be applied.
S b is the basic snow load in accordance with snow map in bs 6399.
The 8th edition massachusetts residential code has replaced figure r301 2 5 in the irc 2009 with table r301 2 5 which gives.
Characteristic ground snow load map taken from uk na to bs en 1991 1 3 parapets and obstructions parapets and other obstructions against which the snow may accumulate cause snow drifts resulting in localised high snow loads well in excess of the uniform snow load.
As an example the current ground snow load requirement for manchester is 70 psf.
A person needing to access the roof in order to repair items.