Considering the fact that the majority of domestic properties use shallow foundations, it stands to reason that this is the area of the subject which is most appealing to the present or prospective homeowner.
Foundations are something which shouldn’t be overlooked by any stretch. In some cases, it’s not unheard of for them to consume as much as 20% of the cost of a building – even though they are only a meter or so underground.
As well as this, compromising on this area of the home should never be considered. As V. Reddy Kancharla will testify, foundations tend to be the source for a lot of problems in buildings. For example, while a crack in a property might appear to be in the top right of one of the walls, the problem might actually be due to foundation failure in the opposite corner.
In other words, this is an area of a house which can get expensive – particularly if the correct foundations aren’t chosen.
Following on from this, we’re now going to take a look at the most common types of shallow foundations and why these are used for most of the housing stock in the country.
If one were to analyze all of the foundations we discuss over this page, strips are probably the most common.
These are foundations which tend to sit underneath a load-bearing wall – meaning they are especially important in modern construction. Specifically, they are used to support lines of loads.
They can be described as a strip of concrete which sits underneath the wall. Sometimes this will just be a standard rectangular shape, while other times it might be stepped. In all cases the concrete will be reinforced to provide extra sturdiness.
The nature of pad foundations means that they aren’t quite as common as the previous type we looked at – but they will still be found in countless homes around the country.
The reason they aren’t as popular is because they only support individual points of a load – rather than a line of a load, like a wall. Ultimately, they tend to be used when structural columns are used in construction. For the typical dwelling, this is something that is rarely turned to, but if you were looking towards a larger, more complicated house, columns might be used.
Again, the foundation can be formed out of concrete in a rectangular shape, or stepped. The concrete will sit under the column and provide that stability.
One of the more interesting types of foundation is the raft. This refers to a foundation which spreads across a large area and unsurprisingly, resembles a raft-like shape.
Rather than the foundation just being based under walls or columns, in this instance it will sit under the whole area of the building.
The advantage of a raft is that it can work very well on uneven ground. The fact that the slab covers such a large area means that it will remain strong if there is ground movement – which could cause subsidence or other structural problems in other foundations.