Few countries share the affinity with the sub-grade level that we Canadians fondly refer to as the basement.
The excavation of the foundation creates this full-height space. On the inside of the basement level, steel, lumber or concrete posts (columns) support the main beams of the house and are important structural elements that should not be altered during subsequent renovations.
The foundation wall rests on a concrete footing, which spreads the full weight of the house out over the ground on firm soil or gravel below the frost line. Foundation walls are insulated to reduce heat loss and the risk of condensation, providing a comfortable space that offers a wide variety of options when considering adding to the overall useable floor space of the home.
As with all aspects of a new home, the basement will settle within the first year or two, often revealing small, dry cracks in the concrete floor slab and walls. Normal shrinkage is common and not cause for concern unless it is in excess of 3 mm, or 1┌8 in.
Your below-grade basement has built in features to prevent seepage, combining a damp-proofing or plastic drainage layer over the foundation wall and the installation of weeping tile along the footing surrounding the perimeter of the house. Also referred to as drain tile, this plastic tubing is pierced with holes and is connected to the storm-water system.
A contract manager for Ballantry Homes emphasizes that anything made of concrete will crack. Even though basement wraps have significantly reduced concerns with regard to seepage, it is always advisable to let a house settle before refinishing the basement.
Frank Spaziani, vice president for Kylemore Homes, refers to the settling time as a drying out period, citing the high content of moisture in the concrete. If the house is constructed properly, including the installation of a basement wrap and a damp proofing layer, Spaziani says refinishing is possible at the time of construction. The largest culprit for basement seepage, he points out, is improper grading. If the earth slopes away from the house, then water penetration is unlikely.
"The move-down market (or empty nesters) are looking to move into a home
that is 100% complete," Spaziani says. "These end-users are often moving into their last home and they want to do it all up front."
Many builders are becoming more considerate of this often-ignored space. Walkout basements are offered, wherever the grade permits. Basement walls are being extended above the grade level to allow for larger windows and ultimately more light.