Dead load build-up
Adds up the weight of a roof, floor, wall or ceiling assembly, layer by layer, from the tables of the ASCE 7-22 Commentary or your own values. The total is a number to copy into a load takeoff, a chasedown or a member calculation: nothing links them.
Inputs of the build-up #
- Assembly: a name for the report.
- Layers, up to 40:
- Table items: Table C3.1-1a, as a weight per area, per inch or per 1/8 inch of thickness; Table C3.1-2 densities, with the thickness; CMU by unit density, thickness and grout spacing.
- Entered weight, or entered density with a thickness, with a name. Use these where you know the product: ASCE 7-22 3.1.2 asks for actual weights, and the table is for when you have no definite information.
- Thickness: for the items rated by thickness. One without a thickness weighs nothing, and a note says so.
- On the slope: a layer measured along a sloped roof.
- Roof pitch: rise per 12. Layers on the slope are converted to the horizontal projection. Other layers are left as entered.
- Tributary width: gives a line load as well. 0 = none.
Checks performed #
| Result | Basis |
|---|---|
| Layer weight | Commentary Tables C3.1-1a, C3.1-2, or entered |
| Total | The sum of the layers; on the horizontal projection when a layer is on the slope |
| Line load | Total × tributary width |
The type adds weights and reads Calculated. It has no drawing: most layers have no thickness in the calculation, so a section would be invented. Masonry weights include mortar but not plaster: add the plaster item for each plastered face. The table has a considerable range for some constructions, as its commentary says: check the actual product where it matters.
Limitations #
- Fixed equipment, solar panels and vegetative roofs are yours to enter as layers.
- The psf table prints the slate floor finish "per mm thickness" with 15. Its SI table has 0.028 kN/m² per mm, which is 15 psf per inch. It is taken per inch here and its name says so.
- A metric assembly converts the psf table exactly. It does not use the rounded values of Table C3.1-1b.
- The density table gives ranges for some lightweight concretes. Those rows are not offered: enter the density.
Verification examples #
Verification status: 22 values compared in 22 examples (22 published, 0 hand calculations from the cited equations): 22 within tolerance, 0 recorded deviations. Code basis: the provisions it uses were read in the target edition.
| Example | Source | Values |
|---|---|---|
| Table cells | ASCE 7-22 Commentary, Table C3.1-1a | 17 cells across the kinds of row, each at the value printed |
| Densities | ASCE 7-22 Commentary, Table C3.1-2 | Reinforced stone concrete, grout |
No published take-off is reproduced. Hand additions cover the total, the slope and the line load.