The term “post in ground” refers to a timber frame construction technique where workers drive structural supports directly into the ground. Examples of this type of construction can be seen in many communities around the world, primarily at archaeological sites, as this building technique is not very durable. In existing structures with post in ground construction, it is often necessary to do restoration work to keep the structure stable.
To build post in ground buildings, people need large beams made from durable, strong wood. In the simplest construction, people just use tree trunks as posts. The builder digs a series of holes and sinks the posts into them, packing the holes with dirt and other fill material from around the site. These posts will act as structural supports, allowing the builder to create framing around them. Post in ground structures may have dirt or raised floors, depending on the builder's preference, and can be multiple stories in some cases.
Also known as earthfast construction, this technique is very old. Early human societies used forms of it to build everything from pit houses to freestanding structures. The major drawback to the post in ground technique is the risk of rot in the wood. By remaining in direct contact with the soil, the wood can attract mold and other microorganisms. It often stays very moist, facilitating growth of fungal colonies. Eventually the post will deteriorate, and if enough posts start to break down, the structure can fall.
There are some techniques people can use to make post in ground construction more durable. One option involves dipping the posts in creosote or other treatments before putting them in the ground. This can repel microorganisms and help the posts last longer. Packing gravel to promote drainage can help, as can installing openings for ventilation to keep air and light moving around the base of the posts to discourage fungal colonization.
Restoration of a post in ground structure requires builders to use shoring to support the building while they remove and replace damaged posts. To maintain the integrity of the building, builders can hide protective measures like metal sheeting under the ground, allowing the building to retain the look of a traditional structure while preventing breakdown of the posts. In dry, warm climates, the climate may be less prone to mold and mildew, and this can help naturally preserve a structure built in this style.