Spray Foam Insulation

Posted on: February 2nd, 2011 | 6 Comments

While more expensive than traditional insulation, “Spray Foam” is an innovative and highly effective product to consider when remodeling or constructing a home. In today’s episode John and Matthew discuss its benefits.

  • http://Www.endeavourdevelopments.com Ernest

    Hi,
    There are a few points you should also mention: 1) 2lbs spray foam now needs to have vapor barrier over it. 2) it also needs to be covered with a product like drywall

  • Matthew North

    Ernest – thanks for your comments! Yes, in Calgary we are required to have the poly over the 2lb foam even though the manufacturers of the products say it can act as the vapor barrier. I would be interested to hear from viewers in other jurisdictions if local building codes also require poly over the 2lb foam. And Ernest, you are correct about the fact that it needs to be covered by drywall. This is particularly important in mechanical rooms – building inspectors are very diligent about this point – if you spray foam the joist ends above the basement foundation wall make sure that the foam is covered by drywall before the mechanical system and furnace is installed – it is almost impossible to do this after the fact! Another point about spray foam – even though some of it is soy based, it is not a food source for pests and insects, so no need to be concerned about that.

  • Theresa@NY

    Can the sprayed foam be removed at some future date in case you want to do a renovation or need to do a repair or change a window opening or something? I always wonder about that when I see a TV show where it’s being applied – how do you deal with it in the future.

    Also I wonder if there’s any issue of extra toxicity if there should be a fire; I know fires are generally nasty but you don’t want to make it worse…

  • Matthew North

    Hello Theresa@NY – thanks for your questions – spray foam can be removed if a repair or renovation is done in the future. It takes more time to remove than batt insulation as it needs to be scraped out – but it is possible to remove. When removed, spray foam does leave some permanent residue on the studs – similar to a glue residue. Your question about toxicity during a fire is an interesting one which I do not know the answer to off hand. I will see if I can find out more information about this and post it.

  • http://deleted S.N.

    Hi all
    Great discussion, I would like to add one more point of view. Changing the insulation and heating system of the house is not a simple process. Thermal insulation and heating system need to be designed as a single system. If you mismatch those two parts you can do more harm than good. For example, if you install new heat pump and you didn’t change thermal insulation properties of the house so it is appropriate to new system, new heating system will not be able to generate enough heat to heat the house (because due to the lack of insulation house loses great amount of heat). It is the same story with walls/windows, buying new high performance windows can be waste of money if the walls are no good….
    Installation of any element is crucial, badly installed windows can generate problems like mold or accumulation of condensation…. (This is also true with vapor barrier)….
    So, I suggest consulting a professional that can make plan for heat insulation and heating renovation for the whole house. Only then you can be sure that installed elements will work properly.
    I don’t know how it works in Canada/USA, but in EU we are encouraged by government to invest in renovation of heating/insulation systems in houses. This is done in few steps:
    Professional makes an assessment of existing condition, and makes a project for the renovation.
    This usually consists of total reconstruction of the facade, (walls windows), roof, and with special attention to thermal weak points of the house (balcony-wall connection, wall-foundation…). New heating and ventilation system is also installed. This process insures quality, but it is also expensive.
    Now the bad side: EU made a detailed and complicated rules and regulations regarding insulation and heating systems. Unfortunately they don’t take into consideration local climate. So new house in Italy is being built according to the almost same regulations like one in Germany. Up to 50 years ago, houses were built according to local climate specifics, elements of the house (openings, orientation of the spaces were made in a way that house fits its environment, and that helped with cooling and heating. Just alike John&Matthew sad in video „Air Conditioners – Part one“you should use local climate to help you heat and cool the house in a natural way.
    So, if you saw a beautiful south facing living room with floor to ceiling windows and no shading at your friend’s house in Edmonton Canada, and you decided to do same at your house in Arizona, and you have overheating problem, bad air-condition system did not cause problem, bad design did.

    S.N.

  • Sam

    For my location in mid US foam runs 200-250% more than batt insulation, but it is still worth the extra cost. Your comment concerning how the foam is installed is very accurate. If the foam is sprayed in the center of the space between studs, it will shrink and leave gaps between the foam and the stud (or ceiling joist).
    At this year’s Iternational Builder’s Show,there was talk of using a combination of insulation with a thin layer of foam initially for air sealing and batts on top of the foam. The main advantage is lower cost. Any thoughts?