Attic Insulation

I told you that when we moved into the house in 2007 the furnace would come on every 20 minutes. Now we don’t use it at all.

Cross section of the house as it is
Cross section of the house as it is

A lot of that has to do with insulation. In 2008, with a lot of help from Dave The Father-in-Law, we did just about all we could do to seal and insulate. It was Dave who taught me these basic principles of home insulation and they have been confirmed by all the tradespeople I have talked to since.

You want to keep the moist warm air from escaping into the walls and causing mold so you use plastic vapour-barrier on as many inside surfaces as you can reach. On the outside of that you want as much insulation as you can get.

Building codes are regularly updated to require more insulation, but they are still just minimum standards. Every contractor you talk to will assume that you want to insulate to this standard and no further to reduce the cost of your renovation. In a society where we think of houses as real estate first and homes second–where the resale value is more important than the energy efficiency–this is a reasonable assumption. A few contractors will even advise against going further because you might not get a return on your investment.

The big secret is that you can add AS MUCH AS YOU WANT. It’s true that the money you spend on the 5th layer is going to save you less money than the 1st layer did, but the more you add, the more you will reduce your heating bills and the less energy you will use.

Where you stop is a personal choice. Some people buy granite countertops, I buy insulation. That’s how I roll. Given that homes using less energy is good for the local economy, the provincial economy, the national economy and the planet, I think government should help guys like me out a little more. Just sayin’.

Upstairs as-is
Upstairs as-is
The attic spaces
The attic spaces
old rock-wool

In the attic we had very little insulation to begin with. The space needed a mixture of approaches, too. There was the floor of the attic on the east and west and also above the ceiling. These triangular spaces have hatches for access and there was crumbling rock-wool insulation which could have been there since the 20s. Do you know what steel wool looks like? Rock-wool looks like that, but it’s made from rock, not steel. The rock-wool was about 3cm thick at best between the joists on the floor of the attic.


Dave had, over the years, added other insulation that he came across. On the floor of the east attic is some flaky white vermiculite. This stuff often contained asbestos which is a real problem. We had it tested and were happy to learn that there is no asbestos in our vermiculite. On the west side there was some crushed up pieces of styrofoam packing material. We can recycle styrofoam in Maple Ridge now, but for all those year when you couldn’t, insulating your attic with it was a pretty good solution.

Can you spot the ceiling joists melting the snow?
Can you spot the ceiling joists melting the snow?

Between the sloped ceilings of the kids’ bedrooms and the roof is about 4 inches of space to insulate. When the in-laws put a new roof on 15 or 20 years ago, they added pink fiberglass insulation. I don’t know if any existed there before. These days there are better products on the market such as rigid foam, but with such a small space to fill, and the joists carrying heat from the ceiling to the roof, there is only so much you can do. When is snows, these are the sections of roof the snow disappears from first.

Pink fiberglass under the roof
Pink fiberglass under the roof

We covered the walls of the rooms with vapour barrier first. You have to use special red tape to seal the seams so that it is as air-tight as possible.

Next we covered the walls with thin drywall. Drywall doesn’t really insulate, but it is a fire retardant and another layer of something.

The result was a nice new paintable surface with polyurethane vapour barrier and 3/4 inch shiplap interlocking boards behind it. Several people have assumed we have lath and plaster in our walls because of the era they were constructed but nope, shiplap with heavy wallpaper all the way.

Heading into winter one year and wanting to keep the kids active indoors, I was able to bolt climbing gromits, a trapeze and a rope ladder right into the walls and ceiling, without worrying too much about locating studs to drill into. As proof, here is a series of photos taken by my daughter in my son’s bedroom in 2012 of balls hanging from the ceiling and gromits on the wall.

Dave shook his head at this a little; all that work putting up the vapour barrier and now I was puncturing it? Sigh.

With the interior taken care of and the rooms turned kid-friendly, we set about insulating the attic spaces.

The result--a mix of methods
The result–a mix of methods in the attic

The floor of the east attic is over the kitchen and the floor of the west attic is over the living room. Ideally there should be a vapour-barrier keeping the warm moist air in those rooms. However, we couldn’t put vapour-barrier on those ceilings as easily as we had in the kids’ bedrooms and the floor of the attics were covered with rock-wool, vermiculite, styrofoam etc. Even if we cleaned all that stuff out, the plastic would have to follow the contours of the joists–what a pain! Simply laying the plastic over the existing insulation would have trapped the moisture from the rooms below in it and cause mold.

Nope. Instead we simply added batts of insulation on top of the remnants of old insulation. There was lots of room so we added two layers. There was lots of crawling around in cramped spaces by yours-truly I can tell you! With no vapour barrier, it’s not a perfect result, but it’s much better. A more expensive, complete solution would have been spray-foam which doubles as a vapour-barrier.

We used Roxul batt insulation, which is like the evolution of the old rock wool from the 20s. This stuff is produced sustainably in BC. It’s good. Go buy it.

On the attic side of the kids’ walls we were able to fit one layer of Roxul and hold it there with reflective bubble-wrap which helps reflect the heat out of the rooms in the summer.

Bubblr wrap and new wiring!
Bubblr wrap and new wiring!

All this attic insulation is probably the single biggest reason we can heat our home using the wood-burning insert and a couple of space heaters. We thought we did a pretty good job, but Nichole’s report brought me down to earth. There is a lot of room for improvement in this old leaky house. Wait til I post her results and you’ll see what I mean.

A nice deep blanket on the other side of the attic door
A nice deep blanket on the other side of the attic door (which we insulated with styrofoam)

Published by

James Rowley

James lives in Maple Ridge, BC, Canada with his amazing partner, Leanne Koehn, and their two amazing kids in their beautiful house. He studied Science and English Literature at the University of British Columbia where he met Leanne. He also studied acting for a while at Studio 58 in Vancouver. He works as a teacher of English and curriculum writer for new Canadians.

4 thoughts on “Attic Insulation”

Leave a Reply

Your email address will not be published. Required fields are marked *