Foundations Information

Block foundation

Pros

It is possible for a home owner to build a block basement. There are several books available on the subject. It requires basic concrete knowledge, and a minimum of tools and the material is relatively inexpensive. You can save a great deal of money on labor, but it is hard back breaking work. You can expect to move several tons of material in a day’s work. And if not done properly, you will have problems constructing the home in nearly every stage of the framing process.

You can make the top of the basement wall perfectly level due to the fact that the blocks are made in a mold and have a flat surface.

Concrete blocks are hollow. When stacked on top of each other, the holes extend to the footing. Steel rods can be placed in these holes and then they can be filled with concrete. You can make a very strong foundation by doing this. Some believe it may even be stronger than a poured wall foundation.

Since the blocks that are being installed are already cured (dry), there is less chance of shrinkage which creates cracks as opposed to a poured wall foundation which dries on site.

Block has a better insulation value. Heat transfer is controlled by creating dead air space. Concrete blocks have the hollows in them creating the dead air space. In addition, insulation can be added in the hollows of the block creating even more insulating value. Check out this link for block insulating tips.

Cons

Many think standard block foundations do not look as nice as a poured wall foundation. Although this problem can be addressed with architectural blocks or coating the block wall with a thin textured layer of concrete or stucco.

Some feel the numerous mortar joints in a block foundation increases the chances of leakage. However both a block foundation and a poured wall foundation will leak if not sealed properly. Regardless of the foundation type, if it is sealed properly, it will not leak.

If a block foundation is not reinforced with steel and concrete, the walls will be much weaker than poured walls.

Typically, a block foundation takes more time to construct vs. a poured foundation. However, you can backfill a block basement in a shorter amount of time than a you can backfill a poured wall basement. This is because a poured wall basement has to dry in the field. Only the seems in a block basement need to cure. The blocks themselves are already dry.

Poured wall foundation

Pros

A poured concrete foundation is flexible in the sense that it can be formed into almost any shape. This allows the home owner more choices of house plans.

It is believed that a poured wall foundation is able to support more weight. As stated above, if properly reinforced, block walls can be as strong (and some argue stronger) than poured walls.

A poured wall foundation is believed to have less chance of leakage because there are no seems unlike a block foundation. But just like a block wall, it has to be sealed or it will leak. All concrete wicks moisture.

A poured foundation can usually be installed faster than a block foundation. It can not be backfilled as quickly as a block foundation due to the fact it needs a longer drying time.

Most people like the look of a poured concrete wall vs. a block wall. In addition, dye can be added to color the walls and forms can be added to give the wall a variety of textured looks, like the picture to the right.

Cons

Poured walls strength can be influenced by how much water is added to the concrete mixture in the field. Block is manufactured reducing, if no eliminating the chance for improper mixtures.

Poured walls do not have the insulation value that block walls have. That being said, there are companies that offer many solutions to the insulation issue. There are many options available today. Ask you contractor about the options he offers. There are some other helpful tips at this link.

Concrete wall are not a straight at the top. The concrete tends to have small valleys and peaks in it when it dries. This can make it more difficult to get things level from the start.

The weather can affect the rate at which a poured basement dries. If the walls dry to quickly, cracking is likely.

Wood foundation

Pros

Easy to build. The same crew that frames your house can frame the basement. It can be built on a bed of gravel therefore eliminating the need for concrete footings. You can choose either a concrete slab floor or a wood frame floor. If you use wood, then you eliminate the concrete contractor saving time and money.

Can accommodate almost any floor plan.

A wood foundation is easy to insulate. Just put bat insulation between the studs, just like you would on the main levels.

Wood foundations are easy to finish. They are constructed very similar to the main levels. The studs are already in place for drywall installation unlike concrete basements.

Dryer. As stated earlier, concrete of any kind wicks moisture. That is why basements always feel damp. That damp feeling is almost non existent in a wood foundation basement. Unless the basement has a good dehumidifier in it, I can almost always tell if I am in a finished basement made of concrete or one that is made of wood. It is very noticeable in my opinion.

Easy to install wiring and plumbing.

Less expensive.

Cons

If not constructed properly it will leak or structurally fail.

Will not last as long as concrete. That being said, most proponents for and against, think that a wood foundation will last the life time of the owner if properly constructed. Many wood suppliers warranty there wood products for 75 years against decay and infestation. Many say wood foundations will last for centuries.

Low consumer confidence. Most consumers think a wood foundation is inferior to a concrete foundation. This means that the home will not appeal to as many consumers should you want to sell it.

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