Insulating Basement Walls

Very few residential basements are free from moisture and damp. The elevation (or none) of the basement, method of wall construction, rising damp  and poor or no insulation are the  factors that make basement walls retain moisture. More often than not, a “wet” basement is of no consequence to the homeowners whereas a warm and dry basement could be put into good use.  Proper insulation of the basement walls is easy and the ensuing results quite useful. You and your family can put into good use a dry basement. A properly insulated basement could save you on electric bills.

BEFORE you insulate a basement with poured concrete formed walls, strongly consider letting the new construction sit for a year. Cement takes a long time to cure and can take up to a year for a poured wall.

Foam Board

Polyurethane foam board is an expensive, but effective solution for insulating your basement walls. It can be installed in a studded wall system or applied directly using coin-nails with a ramset.

Bubble Foil

Bubble foils insulation efficiently blocks heat as bubble foil acts as a radiant “fence” during the cold and hot seasons. Bubble foil has been tested and proven to act as a barrier to ward intensely high temperature.  Try to purchase coated bubble foil to obtain up to 3 coats of reflective sheet segregated by a thin synthetic net between each foil panel. This type of insulation is quite resistant to dirt as long as it’s not a single-covered bubble foil.  Application is very simple. Bubble foils come in rolls with adhesive back. All you need to do is roll out and measure the roll of foil, cut it to its desired size, then affix to the basement wall for insulation. Make sure the walls are free from dirt and moisture before installation.

Spray Foam

Spray foam insulation has the capability to last for a very long time as long as it is applied correctly.  Expanding foam insulation is great for sealing up walls and cavities in the basement and in the whole house itself.  This type of insulation is available in canisters with a spray nozzle for DIY job. For specialized application, special equipment is needed and more often than not, is done by professionals. Spray foam is available in a fast rise and slow rise formulation. It is made of a compound of polyurethane liquid that expands, dries and hardens as sealant.  Simple and easy-to-use spray foam in cans available at the local home depot can be used for basement walls and crevices insulation.

Fiberglass Batt

Fiberglass insulation is easy to install and effective. Fiberglass is composed of glass strands in a thick mat. In between the fibers are pockets of air. The glass strands are laid out in a random manner that there is no direct path through the mat for the hot air to pass through.  The installation of fiberglass mat is uncomplicated. Some brands come with peel-off back with adhesive. There are brands that come in rolls and need to be nailed into walls with the use of wooden casing.  Fiberglass is available in rolls and is coated with vapor barriers to ensure that the insulation is protected from moisture.

  • Unfaced fiberglass: This requires that a wall be studded out to hold the fiberglass in place, or the basement was constructed using pre-fabricated cement forms with wood for applying facing materials. Do not cover the insulation with a non-permeable vapor barrier (i.e., polyurethane). The best alternatives are to use unfaced or kraft-faced insulation.
  • Fire-resistant facing: This is available in rolls with a vinyl facing. It is applied to the wall using coins that are ramset into the foundation wall (assuming it is a concrete wall).
  • Dense Pack: Again, this will require a studded wall. You can dense pack a wall with fiberglass. Do not use a non-permeable vapor barrier.

Cellulose Wall Spray

Cellulose is applied using a stabilized cellulose material. It is made of shredded newspaper to which starch (stabilizer) and borax (mold/insect inhibitor) are added. When sprayed, the starch is activated by water causing it to stick in a vertical wall. Due to the fact that water is added to this material, it is absolutely important that a few days are given for this material to dry out. Again, you do not need a vapor barrier for this material, if you do, do not use a non-permeable barrier.