Finished Basements - Subfloor & Insulation

Whether renovating or finishing a new concrete basement, it can be a tough job. Worse yet, having to select the proper building materials in order to avoid mold from forming later on. This article will cover the points necessary to complete a worry free basement for many years to come.

Sub floors - One of the major problems with sub floors in concrete basements is the moisture which builds up over time underneath the sub floor itself. Concrete is a very porous material which absorbs water out of the earth that surrounds it and then finding its way underneath your sub floor. Wood sub floors can be used effectively with proper vapor barrier. I prefer to use 100% plastic floor tiles which snap together and create a guaranteed water vapor tight seal. Another benefit of this sub floor are its mold resistance qualities.

Insulation - When finishing your basement insulation is one of the most important factors if you are trying to achieve a comfortable basement.

• insulation's fit too tight or too loose
• insulation installed against unsealed concrete (I recommend certified vapor barrier against concrete wall and wrap to underneath sub floor)
• cold air from the concrete walls infiltrates into the insulation, giving less R value (measure of thermal resistance)
• difficult to insulate and seal with vapor barrier around main floor joints

Spray foam is by far the best insulation to use for any application. It fills all cavities leaving absolutely no room for moisture. Closed cell spray foam is certified for use in Canada with no additional vapor barrier. It also adds rigidity to the house structure. Spray foam is now environmentally friendly. Soy base spray foam is made up of recycled plastics and soy oils. It offers the same R value factors as the original polyurethane spray foams.

Insulation R Values

• closed cell spray foam - R-7 per inch
• fiberglass insulation - R-3.42 per inch
• rock-wool insulation - R-4 per inch