Are Permanent Wood Foundations Effective?

The foundations of most North American houses are poured concrete, onto which the walls rest beneath ground. However, in the case of timber frame homes, these foundations may extend above ground level to provide dry support. Permanent wood foundations are an alternative, greener option and they do have advantages.

Permanent Wood Foundations & Cellars

Basements and cellars add another dimension to the debate. These are traditionally brick-and-mortar, or cement-block-and-mortar constructions on which the structure above rests.

However, these traditional building materials require large volumes of energy to produce, and some homeowners are wondering whether permanent wood cellars may be a greener alternative.

Permanent Wooden Underground Structures

The first permanent underground wood structures appeared in Canada in the 1950’s, according to Wood Preservation Canada, and others have found them attractive down the years.

Permanent wood foundations have many uses, including crawl spaces, room additions, and knee-wall foundations for garages and mobile homes. Concrete slab-on-grade floors, wood sleeper floors and suspended wood floors can all rest on them with suitable preparation.

How Long Will These Last Before Replacing Them?

The timber should last for a very long long time, provided it is suitably treated beforehand. There is ample evidence of wood surviving in medieval half-timber homes, and historic shipwrecks that surface from time-to-time.

Timber yards pressure-treat timber for foundations using a chromated-copper-arsenate solution.

  • The copper provides resistance to mould, fungus, and rot.
  • While the arsenate repels invading ants and termites,

The finished structures also need to be able to resist pressure from the soil beneath and surrounding them, as well as from wind, rain, and snow above.

permanent wood foundations
Permanent Wood Foundations (Canadian Wood Council)

The Pros and Cons of This Building Technique

There are many benefits to using permanent wood foundations for cellars, basements and other underground support structures:

  • The work completes relatively quickly. The team building a timber home can complete the below-ground work too.
  • The project design lends itself to remote sites, where concrete-pouring services may be unavailable.
  • Installing and back-fitting plumbing and electrical services may be simpler and faster, as should maintenance too.
  • The wood materials are more environmentally responsible. They retain warmth, and this can reduce heating bills.

However, this does not mean that permanent wood foundations for basements have no drawbacks! Cheap timber that is poorly treated may not last as long as expected. Prospective buyers dislike the idea of timber underground. Especially when they learn that it contains arsenic.

This information reaches you courtesy of Valiant Exteriors in Calgary. Reach out to us if you need advice on asphalt shingles, eaves troughs and soffits, and siding for your home.

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Permanent Wood Foundations (Canadian Wood Council)