Exterior Walls



Depending on the age of your home, you may or may not have any insulation in your exterior wall cavities. There are large savings in heating costs and increased comfort available for a reasonable cost if you decide to upgrade the insulation in your exterior walls. The return in comfort and savings will more than justify the initial capital outlay.

If your home was built prior to 1955, it may not have any insulation in its exterior walls. Homes built between 1955 and 1970, generally have an R8 product that is often a rockwool with a paper backing. After 1970 R8-R12 fibreglass and cellulose started to be used more often. It is often hard to know what a house contains given the variability in construction methods, builders and renovations that have occurred over time.



Adding Insulation

It is extremely important to know if and what type of insulation is present in the exterior walls as this will determine if anything can be added to them. Homeowners who have conducted renovations may have a very clear idea of what was in their walls. If you do not know, Alpine’s estimators will try to find areas where there are holes or openings into the exterior walls (such as under sinks or wherever there is exposed plumbing, a void in your drywall or at electrical fixtures/boxes) to try to figure out if insulation is already present; however, this is often very difficult or unreliable. If our crew drills its first few holes and finds that they cannot add any additional insulation, not only will you have unnecessary holes in your walls, we will charge you a $150 patching fee. We hate this outcome because not only do both parties lose money, it negatively impacts our scheduling a great deal. For this reason, your estimator will ask if they can drill two or three small holes into your exterior walls in different locations in order to try to assess the possibility of adding insulation before a crew arrives and dates are set.

Ways to insulate exterior walls

  • The 1 inch hole method
  • Alpine does not employ this method because we feel that it does not provide homeowners with the end result that they are paying for. This meathod does not allow for the blowing hose to extend down into the wall cavity and as a result, the blown insulation is simply dropped into the void, with the hope that it not only finds its way to the bottom but also that it somewhat packs down. Often it does not do either of these and leaves large voids in your walls; somewhat defeating the purpose of the whole enterprise. Companies that employ this method need to use infra-red cameras in order to check their work because there are so many problems getting a complete fill. Alpine has found this technology not to be reliable and it does not address the issue of loose filled insulation settling after installation.



  • 2 inch holes method

  • Instead, Alpine drills 2 inch holes and uses a flexible hose, dense pack method. We will insert a flexible hose down into the bottom of the wall cavity and then using our pressurized system, we backfill the entire cavity with a more densely packed blown cellulose. Only a pressurized back-fill method will guarantee that you are getting full value and maximum insulation in your walls. It also has the added benefit of allowing the workers to direct the hose past many of the everyday obstructions found in wall cavities. If Alpine crews encounter any cross blocking in the cavity, which prevents them from getting to the bottom of the wall, they will drill another hole below the blocking and fill that section separately.

    Once the wall cavity has been filled, the holes are patched and best efforts are made to match the existing finish/colour. In the case of exteriors that have been painted more than 3 months prior to the work being done, it is virtually impossible to match the existing colour of the walls when patching – even when homeowners provide the same paint. For this reason, Alpine cannot take responsibility for or commit to ensuring that the paint or finish of its patches match the remainder of the walls exactly. Crews will colour and texture stucco patches and add rocks to patches for rock dash stucco finishes, in order to best match the existing walls.

    Prior to commencing any work, the crew will walk through the interior of the home to look for areas where the interior wall may not fully cover the wall cavity. If insulation is added without having the interior wall cavity closed off, dusty cellulose material can enter the home. Homeowners are asked to inform crews if they are aware of any areas where the interior wall may not seal off the entire wall cavity. Occasionally “blow-outs” occur where there is a weak spot in the wall and Alpine crews will need to clean up any material that enters the interior of the home. Homeowners are asked to remove pictures or other materials on their walls that could be disturbed while filling takes place.