59 posts · page 4 of 5.
Stop redrawing plans from scratch: import a DXF or PDF and trace the geometry to place supports. Here is how plan import works, the difference between the two, and how to set the scale.
A bearing wall carries floor load as a line reaction per metre, not a point load. Here is how to take a wall down, what feeds its line load, and how it reaches the footing.
Superimposed dead load is the permanent weight added on top of the structure's self weight: finishes, services, ceilings and partitions. Here is what counts and typical values.
A footing carries the column above it plus its own weight. Here is how to find the load for bearing and for footing strength, using service and factored values.
The governing load combination is the one that produces the largest design effect on a member. Here is how to find it, why it varies, and a worked example.
A wall's line load is its weight per metre of length: height times thickness times unit weight. Here is the method, typical material weights, and a worked example.
Tributary area is the floor that loads a member; influence area is the larger area whose load affects it. Here is the difference, the K_LL factor, and why it drives live load reduction.
A slab hands its load to the beams that support it, as a uniform strip in one-way action or as triangles and trapezoids in two-way action. Here is how, with the load shapes.
Loads come in three forms: area loads on slabs, line loads on walls and beams, and point loads at columns. Here is what each means, its units, and how they convert.
How to take one column down by hand: tributary area per floor, load per floor, accumulate down the building, then factor. A full worked example with numbers.
Need tributary areas without the sketch and spreadsheet? StructLoads is a free browser tool that computes them from a plan you draw, exactly and instantly.
An edge column carries about half a bay; a corner column about a quarter. Here is why, with the geometry, the load ratios, and a worked comparison.