Attic Dead Load

Analysis of an attic truss requires multiple load cases with multiple duration factors.

Attic dead load.

A typical wood frame floor covered with carpet or vinyl flooring has a dead load of about 8 pounds per square foot. C determine the total load and proper load duration. Dead load of attic floor when floored 20 lbs. Live loads are people and animals and tangentially the things used by people.

If there s wall board covered ceiling suspended from the underside of that floor the dead load increases to about 10 pounds per square foot. A the top and bottom chord dead load. In rare cases especially in new construction homes the attic may have been built unfinished with the correct flooring in place with the idea that the homeowner could later on finish the space. The values for dead loads in table 3 2 are for commonly used materials and constructions in light frame residential buildings.

This type of truss carries a combination of roof l r or s and floor l loading in addition to the standard top and bottom chord dead loads. Unlike the trussed roof live load and dead load of the rafters and ceiling joists must be accounted for as separate systems. Of floor area dead load on second floor 20 lbs. As a result the live load dead load and distribution of forces are different.

Psf ceiling load for a c ducts plumbing and wiring the attic space is considered uninhabitable but will be used for storage. Storage space dead load of partitions 20 lbs. Since it is possible to use the attic for storage the live load of the attic floor is set at 20 psf according to code. It is also an indeterminate structure with a non triangulated web area which interrupts the normal flow of forces thru the truss.

Dead load of first floor ceiling not plastered 10 lbs. Dead loads are things that do not move. The truss shown below is known as an attic truss or a room in attic truss. 3 3 dead loads dead loads consist of the permanent construction material loads comprising the roof floor wall and foundation systems including claddings finishes and fixed equipment.

The ceiling load may include items like drywall ducts recessed lights bathroom fans and attic insulation. Boxes trunks suitcases etc. The dead load on a floor is determined by the materials used in the floor s construction. Of floor area dead load of partitions 20 lbs.