{"id":11543,"date":"2020-01-26T03:42:12","date_gmt":"2020-01-26T03:42:12","guid":{"rendered":"https:\/\/essential.construction\/cnstrctr\/glossary\/foundation\/"},"modified":"2026-11-03T10:08:37","modified_gmt":"2026-11-03T17:08:37","slug":"foundation","status":"publish","type":"glossary","link":"https:\/\/essential.construction\/academy\/glossary\/foundation\/","title":{"rendered":"Foundation"},"content":{"rendered":"

A foundation<\/strong> is the lowest part of a building’s structure. Its job is to carry the weight of the building and everything in it (plus wind, snow and seismic loads) and transfer it safely into the soil or rock below without excessive settlement. Foundations are usually built of reinforced concrete, sometimes with concrete block foundation walls, and may sit just below the surface or extend deep into the ground.<\/p>\n

For more detail, see our guides Building Foundations 101<\/a> and Foundation Types<\/a>.<\/p>\n

Types of foundations<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
Category<\/th>\nType<\/th>\nTypical use<\/th>\n<\/tr>\n<\/thead>\n
Shallow<\/td>\nStrip (continuous) footing<\/td>\nUnder load-bearing walls<\/td>\n<\/tr>\n
Shallow<\/td>\nPad (spread) footing<\/td>\nUnder individual columns<\/td>\n<\/tr>\n
Shallow<\/td>\nSlab-on-grade<\/td>\nHouses, warehouses, light buildings on good soil<\/td>\n<\/tr>\n
Shallow<\/td>\nRaft (mat) foundation<\/td>\nWhole-building slab where loads are high or soil is weaker<\/td>\n<\/tr>\n
Deep<\/td>\nDriven piles<\/td>\nSteel, concrete or timber piles hammered to a bearing layer<\/td>\n<\/tr>\n
Deep<\/td>\nBored or drilled piles, caissons<\/td>\nHoles drilled and filled with reinforced concrete<\/td>\n<\/tr>\n
Deep<\/td>\nHelical piles<\/td>\nScrewed-in steel piles for additions, decks and light structures<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Shallow foundations are used where good bearing soil is close to the surface. Deep foundations reach down to stronger soil or rock when the upper layers are weak, compressible or full of fill.<\/p>\n

Footing vs foundation<\/h2>\n

The foundation<\/strong> is the whole system below the superstructure: footings, foundation walls, piers, piles, grade beams and slabs. A footing<\/strong> is the widened base at the bottom of a wall or column that spreads its load over a larger area of soil.<\/p>\n

What decides the foundation design<\/h2>\n