Foundations and Construction Systems

Do Now:

On a piece of paper, write down any similarities/differences you can think of between a footing and foundation wall.

The Footing

Load Bearing vs. Non-Load Bearing:

Any component bearing a load outside of its own weight must have a footing.

Depends on frost line

Foundations

Slab Crawl Space

Slab, Crawl Space, and Basement

Basement

Slab - Directly on soil, suitable for most warmer climates and where depth between soil and hard rock is shallow. Cheapest to build, hardest to repair.

Crawl Space - Pier and beam, shallow excavation, most often used in areas where heavy clay content in the soil that can crack slab foundations, or in waterfront or flood prone building.

Basement - Accessible space (sometimes livable) between the soil and the bottom of the first floor, have the advantage of providing useful space, but disadvantage because they are vulnerable to leakage, mold formation, and flooding.

Skeleton-frame Construction

Skeleton-frame construction uses small structural members joined together to share the loads of the structure. When the structural members are covered, they form complete walls, floors, and roofs. This is used frequently in residential construction.

Skeleton-frame ConstructionHere you can see the key elements of a framed structure.

This system is repeated for each floor of the home from the floor joists to ceiling joists.

Below you can see the foundation wall, sill plate and floor joists.

Skeleton-frame Construction Multiple Floors

Here is another illustration that shows how cantilevered structure would be framed.

A cantilevered structure extends out beyond the framing of an existing floor creating a soffit as shown here.

Plank and beam ConstructionIn this example of a Plank and beam construction system you can see the foundation

and other construction components.

Footing and Foundation Size?

We are going to assume that our house foundations are 8” and our footing size is 2’x2’x1’, but they can fluctuate depending on different variables. What do you think some of these variables might be?