Estimating the Quantity of Floor Materials
As the floor in carries the weight of the structure, it is important to determine the material required for it correctly.
• You must be able to recognize special needs such as floor opening, cantilever, and partition support that affect materials requirement.
• Once the needs are determined, you must be able to estimate the quantities of materials needed in order to construct the floor without delay or any added expense such as ordering too much material.
The process begins by checking the building specification for the kinds and dimension of material to be used. It also requires that the blueprint be checked or scaled to determine the dimension of the various components needed.
• Sills sealer, termite shield, and sill
• Girder or beams
• Joist header
Guidelines for Determining Girder and Joist Sizes
Normally, the sizes of the girders and joists used in a building are specified by the architect or structural engineer who designs the building. However, a carpenter should be familiar with the procedure used to determine girder and joist sizes.
The following steps on how to size a girder are keyed to the example first floor plan shown. Assume that a built up girder will be used and the ceiling is drywall (not plaster).
Determine the distance
Find the girder load width
Find the total floor load per square foot carried by the joist and bearing partitions
Find the total load on the girder
Select the proper size of the girder according to the local codes
The following discussion on how to size joists is keyed to example first floor plan shown.
Assume that the plan falls into the 40 pounds live load category and will be built with joist on 16” center and dry wall ceilings.
Determine the length of the joists span
Determine if there is a dead load on the ceiling
Select the proper size of joist