Roof Live Load Vs Dead Load

Reinforced concrete creates the heaviest dead loads but also supports the most weight with its tremendous compressive strength.

Roof live load vs dead load.

The metal building company does provide live load reactions but having inquired of this in the past i ve been informed that the live loads unless specifically stated otherwise refer to roof live loads. Where l r shall not be less than 12 psf and not more than 20 psf. 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. On a roof with a slope greater than 4 to 12 the live load limit is typically adjusted downward from 20 psf to 15 psf to allow for the relatively greater dead load on the steeper roof.

Canpro the metal building company did not break the mezzanine loads into dead live. And also the permanent fixtures present in the structure. Af pa s appendix a lists a variety of live and dead load combinations for floors ceilings and rafters. Dead loads are due to self weight of the structure.

Because live loads depend on structural strength knowledge of the exact planned use of the building is critical. All loads are typically categorized into two types live and dead. Unlike the trussed roof live load and dead load of the rafters and ceiling joists must be accounted for as separate systems. Dead loads depends upon the unit weight of the material.

Ground snow load might seem somewhat confusing until you read the basic premise that is identified in irc section r301 6 which states. L r l o r 1 r 2. Where d is floor dead load. Dead loads includes the self weight of walls floors beams columns etc.

For example appendix a indicates that one type of clay tile roof system has a live load value of 20 psf and a dead load value of 15 psf. This issue of live load vs. The roof shall be designed for the live load indicated in table r301 6 or the snow load indicated. The might of the dead load or lack thereof often defines how much live load it can handle.

As a result the live load dead load and distribution of forces are different. Roof live load reduction. It is simply listed. Dead loads are the permanent loads which are always present.

Roof live load may be reduced by the following equation. Victor staley a building official in the town of brewster mass responds.