Insulation: Spray Foam and Cellulose

Spray foam Setup

Homeowner with hose apparatus used to distribute cellulose through webbing between studs

Cellulose (immediate left).

If you experienced cold rooms that never seemed to heat adequately, an energy audit should be first on the list to identify the problem and take steps to correct it. The key is to follow through so next year the fuel bill and the cold rooms will both change. Think ABC-Attic and attached garages, Basement and Circumference of the building for your air sealing priorities.

Cutting energy costs in the way of fuel consumption begins with a comprehensive game plan. From this you choose what your budget and goals will be to get there. One way is to make sure you have the proper insulation, from the get go or by retrofitting either professionally or small scale by the diy'er.

Attending an insulation workshop sponsored by PAREI (Plymouth Area Renewable Energy Initiative) recently, gave a whole new appreciation for the techniques and skill a professional exhibits when you hire them to do the work, vs. a diy'er.

A new home being constructed locally was the host of this hands on seminar. Working with representatives who demonstrated spray foam apparatus and procedures and cellulose distribution via wand that sprays cellulose inside the wall cavity beneath a sheer membrane overlay, one can see the merit to both applications.

As a homeowner with small area's needing to be addressed, spray foam can be found in the form of individual cans or for larger projects a dual cannister setup for sealing. The latter case, as we were shown, consisted of one bottle (like a small propane bottle) of a mixing agent that activates the other as they flow through hosing to be mixed together at the nozzle tip, and then sprayed. (Extra nozzles should be on hand as, once initiated you need to keep using or it can plug at the nozzle tip, along with gloves, face mask and safety goggles). Nozzle tips vary to allow for varying spray radius to get into small area's around pipes vs. larger spray for between joists.

Avoiding overspray or spraying too densely, is not mastered quickly, but once a rythym is worked out eveness becomes easier to achieve. The key is to not create voids nor underspraying. This can be tricky due to the tight quarters of many of the places you're trying to seal.

Next, the homeowner, a petite woman put on her safety glasses, dust mask, old clothes and went to town with the cellulose dense pack insulation from National Fiber. Cellulose is made primarily with over-issue newsprint and can be treated with borate. (Mined primarily in California and Turkey, borate resembles granulated sugar, pulls out moisture, provides fire, insect and mold resistance and is used commercially in eyewash and cosmetics for instance.)

Think of a reverse vacuum cleaner-instead of the long hose and wand lifting, this hose was expelling the cellulose in the cavity between the studs over which a sheer webbing had allready been stapled quite taut. The bulging wall was filled with 3.5 lbs per square foot. (3 1/2" is the ideal, as air can't pass through that density), then smoothed with a metal roller much like a paint roller, to help evenly distribute and allow the sheetrock to fit correctly. A diy'er could rent an Accu 1 dense packing unit, and is best done with a buddy to keep feeding the unit with the cellulose.

Not only do you get a warmer home from the thermal properties, but also the accoustical deadening. Known as the Sound Transmission Coeffient or STC rating which is the guideline for controlling noise between spaces, cellulose in a typical 2x6 wall with 1/2" drywall on each side yielded an STC 55 rating according to National Fiber for sound attenuation. That translates to the noise of the slumber party in the next room is significantly muffled, as is the lawnmower working outside.

Ultimately, whether you do this yourself, or get estimates to hire a professional, will depend on your goals and budget. Attending workshops offered by PAREI and others are invaluable to help become more informed and allow you hands on experience to determine the best fit for your skill level. Saving money is a great motivator, but being warmer next winter...priceless