Roof Live Load Tributary Area

The load w that that unit length supports equals the tributary area 1 tw times the uniform pressure load q.

Roof live load tributary area.

0 9d 1 0w a load factor of 1 6 when adding to load 7. 1 2d 1 0e l 0 2s when h loads are present they shall have 6. 0 9d 1 0e effect or 0 9 when resisting the load when permanent. So a 100 sqft deck would be designed to support 5000 lbs.

Minimum design loads for buildings and other structures location uniform load psf. The area that it supports equals the tributary width times the unit length. Our sample homes are in an area where the snow load is 50 pounds per square foot of roof area treat snow as live load. Tributary width is 7 ft 5 ft 12 ft.

Hence the load per that unit length is w 1 tw q q tw. Additional collateral gravity cg and collateral uplift cu loads can be added to the building or shape as required on the live load tab as well to account for additional loading on the roof surfaces. Tributary loading or tributary widthis the accumulation of loads that are directed toward a particular structural member. The reduction formula has two reduction terms.

Minimum uniformly distributed live loads adapted from sei asce 7 10. The amount of reduction allowed depends on the tributary area that a member supports and is automatically determined. Some building codes will permit the live load to be reduced only for some design members. Note to builder customer.

One for the tributary area supported by the structural element r 1 and the other for the slope of the roof surface r 2. The left wall has 7 ft of tributary width and would receive a load of 700 plf. Now let s find the tributary areas of a deck to determine the maximum load capacity of your deck start by calculating its total area and multiply by 50 psf. The idealized beam loading diagram is shown in figure ta 2 3.

R 1 is formulated in such a way that there is no reduction for tributary areas less than 200 sqft and is maximum when the tributary area reaches 600 sqft varying linearly in between. Example problem of determining distributed load on a beam and column reactions for a simple beam and plank system with unsymmetrical bay sizes reference. It goes without saying that in a warmer climate the snow load probably would be less so you need to check your code book for live loads and dead loads in your region. Tributary areas many floor systems consist of a reinforced concrete slab sup ported on a rectangular grid of beams.

Don t get confused with what weight you might think or want to load the deck with.