Building a pier foundation requires less financial investment than building a strip or mat foundation. But it is almost equally reliable. It should be noted that this type of foundation structures is successfully used only for light (mostly wooden) houses and utility buildings.
Pier Foundation Construction Materials
A pier foundation is naturally represented by a system of piers the structure rests on.
The piers can be made of:
- Rubble concrete
See also Foundation Construction Materials
Building a Concrete Mat Foundation
Stake out the area for the piers. The piers have to be located at all corners of the structure and at the intersection of the outer walls with the inner ones. The distance between them varies from 1.5 m to 2 m.
Dig the trenches (the depth is the same as the soil and groundwater freezing levels). The size of each trench is 30 × 30 cm.
Fill the bottom with coarse sand or gravel and gently ram it down.
Install wooden formwork.
To reinforce the structure, lay the reinforcing mesh on the bottom.
Fill the trench with concrete.
After the concrete hardens, cover the upper parts of the piers with a waterproofing layer — tar felt secured with mastic asphalt.
In order to make the structure more monolithic, it can be strengthened with a cap — a reinforced concrete “belt” connecting the upper parts of the piers and evenly distributing the load between them. The cap can be below the ground or it can be high enough to protrude above the ground.