Building A Log Home – Part 2, Foundation / Basement


Posted by Hermann Thoene | Posted in Building A Log Home | Posted on 01-08-2010

Log homes can be built on top of any common foundation. The most common types of foundation in North America are these:

Slab-on-grade Foundation

A concrete slab is poured into a mold directly into the ground. This slab serves directly as the floor for the main level of the home. This type of foundation is cheap to build, but should not be used in extremely cold climates, where the ground freezes for long periods of time. Slab-on-grade foundations can provide a good economical solution for relatively flat building lots in mild or moderate climates. If used in combination with radiant in floor heating the slab can be a beautiful and comfortable finished floor.

One problem with slab-on-grade and log homes is plumbing and electric: The subfloor of the main level of a house provides easy accessible space to run vents, plumbing pipes and electric cables. When using a slab-on-grade the plumbing and electric installation requires more planning, as everything needs to be laid out in advance, so that the pipes can be placed inside the concrete.

Crawl space

This is a non-insulated basement type where one cannot stand, mostly somewhere around 40 inches high. It keeps the house off the ground to protect it from moisture and insects, and offers convenient access to plumbing and electric installation. The bottom surface of the crawl space can either be soil or poured concrete. It can be used for some storage, but it’s not considered living space. A crawl space can be used to create a level building area on a sloped lot, and it keeps the house higher off the ground to provide better protection from weather and insects.

Full height basement
A basement provides a lot of additional living space, that can be used for storage, a garage, extra bedrooms, a recreation area, or to build a secondary suite. Basements can be partially under ground or above ground. On sloped properties basements can be fully above ground on one side, and mostly under ground on the other side. Basements provide a lot of benefits, but the building costs are significantly higher as the other options described above.

ICF Basement

Depending on your choice and size of basement or foundation, the construction time will vary from a few weeks to several months.

For our show home in Saanich I chose to build a full hight basement with ICF blocks. The Styrofoam blocks look like huge Lego for adults. The walls are built with these blocks, and window and door openings are framed into the walls. The blocks have plastic clips to hold rebar. At the end, concrete is poured into the space between the 2 styrofoam walls.

This method has many advantages:

  • Saves time and labor cost, as no traditional wall framing is required
  • Provides and excellent insulation. The ICF blocks I used resulted in a R28 insulated wall
  • Saves time and labor for finishing the inside walls: Drywall can be drilled directly into the styrofoam, no additional framing required
  • Reduced amount of garbage during basement construction

The material cost of an ICF basement is higher then building a “regular” concrete basement. But the time savings and better insulation will offset that.

Our building team took about 3 weeks with 2 people from building the footings until pouring the concrete for all ICF walls.