Insulation and airsealing

As you may expect, we have been busily chugging along on what we affectionately call “the big house” which is in direct correlation to the space we currently occupy “the tiny house”.  After our holiday vacation, we returned to the dusty work of blowing in the cellulose.  To prep the space, we stapled up Insulweb with upholstery staplers.  Once the blowing began, it went pretty quick.  It took about 2 ½ days to do the blowing.  Our roof being 17.5″ thick took a little more work.  I think that Whip (our insulator) made three passes into each bay to ensure that the proper density was reached.

Our insulation, like many of our favorite things, is made in Quebec!


Here is the machine with a bag ready to be broken up and blown into the shell:



It was difficult to estimate the exact amount of cellulose needed – I overestimated and we had 100 bags left over!

In the next picture, you can see the Intello billowing out after the cellulose is installed behind it.  It is definitely a good idea to not space the strapping (or framing if you’re blowing directly behind the Intello) larger than 16″ oc.  We had relatively few staple pops which we were glad for.  Friends of ours did 24″ oc spacing and because many staples popped, they had to put a dab of caulk atop of every staple to ensure the airtightness.


In this picture, we are in the process of blowing.  Some wall bays are done, some are empty. The cavities between the floor joists have been initially filled from above.  He then came back and inserted his hose from below the joists to bring the density up.


An up close shot of the staples holding well.


Whip filling a bay.


Whip bringing up the density of the lower roof cavities


Ella named me the “dusty man”


After installation, we vacuumed everything!


And most of the wall bays, because they are 24″ oc, needed to be rolled flat.  It is normal for the cellulose to bulge during blowing, but when rolled with a roller it flattens out so that sheetrock, or in our case, strapping, can be installed atop the studs.


Then the air sealing fun started.  Our primary air barrier is an interior one on the inside of the wall studs (the Intello).  This means that we want to seal every crack and crevice as best we can.  We tape all seams and use an acoustical sealant (tremco) around all window and door penetrations to minimize air leakage.  Around windows we used Pro Clima’s Profil tape.  It is a very nice tape to work with.  It has multiple sized release strips on the back so it makes it very easy to tape in tight corners like from a window frame to the rough opening frame.  We have been really impressed with the ease of workability and the tenacious adhesion of the pro clima tapes.  They are top notch!  (with one exception – the extoseal.  It gets a little thin when stretched.  I have never used DuPont Flexwrap, but would try it and see if I like it better than the Extoseal)


Here you can see how we taped around each joist to obtain a complete seal.



Once we finished with the air sealing, we needed to make a major decision about the layout of our kitchen.  To help us visualize it, we made a life size mock-up with clamps, 2×4’s and saw horses.  It is the best way to quickly get a feel for the finished space with different options.


Then the next task at hand was adding interior partitions upstairs as well as framing out the ceilings.  Here is our solatube capturing lots of light!


Upstairs partition wall…


One traditional difficulty with keeping the integrity of the internal air barrier comes from electrical boxes and wiring.  It is difficult to seal all electrical boxes when they are installed in the traditional fashion.  To solve that problem, it is recommended to add a service cavity on the inside of the air barrier.  We’re adding 2×3’s to give us a 1.5″ space for boxes and wires and some plumbing pipes (larger pipes will require a larger space that will be hidden behind cabinets…. later).  Wires can be slipped behind the 2×3’s in the middle of the bays by compressing the insulation a little..  This wall is ready for wiring and then drywall (with the exception of one 2×3 at the bottom of the window)


We’ve also been framing the knee walls at the edges of the room.


Our next projects are to continue with service cavity installation downstairs, build stairs, and begin wiring… We’ve also been working to design our solar PV system.  There is a lot of good information on the web about it, but we would like to consult with a PV professional about a few details.  If anyone knows of someone in the Brattleboro/Greenfield area who could do some consulting, please connect us!


4 thoughts on “Insulation and airsealing

  1. Wow, it’s looking like it’s getting balmy in there. And I love the burning man photo Michael. What are u doing with the extra bags…

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s