Insulation part 2

The cellulose being blown in

Feeding the hopper

After the radiant barrier was all installed, it was time to put in the wetpack cellulose insulation.  At 86 MJ/m^3 , it is a much lower embodied energy insulation than either fiberglass bat (336 MJ/m^3) or the polyurethane insulation (2160 MJ/m^3).  While it is not quite as high a performance an insulation as the polyurethane, we are installing it in 6″ thick walls which means we’ll have plenty of insulation with its R value of 3.7 and its nice ability to fill in all the small spaces around wires, pipes and electrical boxes.

The finished productBlowing it in is a messy job with one guy spraying the cellulose mixed with water, binders and a fire retardant into the cavity, and another guy sucking up the excess to be run through the mixer machine and blown in again.

Down at the truck is the machine that powers all of this with another guy busy dumping in more cellulose mix into the big hopper feeding the blower hose.

When the cavity is finally filled, it is leveled off and left to dry.  In thin areas, the cellulose is blown in behind a mesh to keep it in place.

In one place in the house you can see the three major types of insulation we are using – cellulose, straw bale and foam insulation all meeting up in one spot.

Where three types of insulation meet

1 reply
  1. kamiel jansen
    kamiel jansen says:

    Hi Catherine Mohr,

    I saw youre video on TED it was interesthing, the company where i work in the Netherlands is busy with this sustainability things for over 20 years now. To geek it a little bit up, energy is far out the biggest milieu effect but not the only one. We defined 17 more milieu effects like acidification, Human/animal toxicities, biotic and abiotic exhaustion etc. We compared all this effects with the twin2002 model, and then we see whats the best material. For a living home we go out from a live time of 75 years, that’s probably shorter in America because of the way youre houses are made. After that some materials get a rest value (for example the aluminium windows, they can get a good recycling). In the 75 year we build in some maintenance cycles (like a wooden window Will be painted around every 5 year) this will have some milieu effects as well. Once we got all this information we can define whats the best material.

    But the best material isn’t always the best in every project. For example isolatie: The best isolation material for a flat roof is cork, but cork is also very heavy so if you wana have a high value isolation you need to make the construction heavier. Ad that moment it sometimes can be better to use polystyrene, witch is lighter and have higher isolation value

    Gl ad youre home and hope i helped you a bit with making the right decision (and that you understand my bad English) If you got questions you can ask at kamiel.jansen@


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