| Self - Help construction of 1-story buildings |
|Detailed planning for construction|
In general, the best way to decide what the foundation walls will be made of is to choose the least expensive and most easily accessible material.
Once the choice has been made between rock and blocks, the depth of the trenches and the dimensions of the footing and foundation wall may be approximately determined by using the figures outlined on pages 85-86.
It is important to remember, however, that these preliminary figures are only approximate guidelines. Any number of local conditions can make a deeper, stronger foundation advisable.
One of the best ways to determine whether preliminary foundation plans are safe is to compare them with the foundation structures of buildings in the local area. The field worker or community member should ask:
• How deep are the foundations of buildings that have cracked walls or other signs of weakness?
• How deep are the foundations of buildings that have lasted well?
• How wide and thick are the foundation footings and walls of weak buildings? Of strong buildings?
• What are the foundations of weak buildings made of? What are the foundations of strong buildings made of?
If preliminary plans for the foundation are similar to those of strong buildings built nearby on the same kind of soil in the local area, they should be safe to use. If the preliminary plans are similar to those of weak buildings they should be strengthened before the start of construction.