Ice Dam Refresher

The Green Building Advisor recently released a helpful article on ice dams. Ice dams are caused by the combination of 1) a sub-freezing outdoor temperature, 2) snow on the roof, and 3) a roof/attic that is above freezing. With this combination, the heat from the living space escapes out through the attic, melting the snow, which then runs down and re-freezes at the edge of the roof. This can cause damage to gutters and shingles, and can cause water leakage into the wall underneath the bottom edge of the roof. This image from the CMHC website illustrates the problem well.


How do you prevent ice dams?

1. Seal air leaks in your attic.
2. Increase your attic insulation (this depends on your climate zone, but for us the target is R-50).
3. Improve ventilation between the insulation and roof sheathing.
4. Cover the roof sheathing (i.e. underneath shingles) with rubberized membrane underlayment.

It is important to note that the first two steps (air sealing and insulation) will also help with the energy efficiency of your home. The third step (ventilation) might help with ice damming if your air sealing and insulation is not sufficient. The fourth step (ice and water shield) will do nothing to prevent ice damming, but will help to prevent water leakage caused by the ice dam.

If none of these options are available to you at this time, you can attach electrical cables to melt the snow/ice on the bottom portion of the roof, or use salt (which would need to be regularly replenished) to melt ice dams.

EnerGuide Rating

We received a new energy efficiency rating of 70 for our house. The rating was 49 prior to our recent improvements, and that number was given to us after we installed spray foam insulation to go from R0 to R20 on our first and second floor walls, so the original number for our house would have been even lower than that.

For perspective, here are the ratings provided online for various types of houses:

• New house built to building code standards: 65-72
• New house with some energy-efficiency improvements: 73-79
• Energy-efficient new house: 80-90
• House requiring little or no purchased energy: 91-100

We plan to make some more improvements to our home that should help with energy efficiency (i.e. vapour barrier and drywall in basement and sunroom, new front and side doors), so in the end our house should be somewhere in the mid-70s according to this scale (the target number for our style of house is 74).

Energy Audit Complete

Our follow-up energy audit was completed yesterday, which is a big relief. We worked hard during the last six weeks and managed to finish everything on our "to do" list. Sorry for not posting information as we worked, but it was an exhausting month and I just didn't have the energy to keep up with photos/posts when there was so much work to be done. I'll post a few summaries of the work over the next week.

Here is a rundown of the energy audit rebates we hope to get:

• Furnace and A/C unit - Completed 18 months ago.
• Improve attic insulation from R0 to R50 - We hired Tropical Insulation to do this for us.
• Insulate basement walls - Completed last weekend. We did R28 on most of the walls and R5 beside the stairs (space constraints), plus our house is a semi, so I'm not sure how much we'll get here, but hopefully at least 60% of the maximum rebate.
• Insulate basement headers - Completed last weekend to R28.
• Window replacements - Replaced three basement windows (one not installed yet, so we didn't get all four) and two first floor windows.
• Air seal improvements - Not sure if we'll get this, but hopefully the above improvements will help.

We will have to wait to find out our exact rebate, but it should be around $5000, which will pay for a good portion of the work we have done in the basement thus far. Our biggest mistake was not doing the initial energy audit before insulating our exterior walls, as this would have resulted in another $3000 in rebates.

The Clock is Ticking

We have been procrastinating big time on the tasks that need to be completed in order for us to maximize our ecoEnergy rebates. We have a long to-do list, and a little over six weeks until we need to conduct the follow-up audit (must be done within 18 months of initial audit).

1. Insulate attic - We currently have R0 (yes, that is a zero), so we should have done this a long time ago, but somehow it just never topped the task list. We have scheduled a contractor to install cellulose insulation to R50 later this week, as this is actually cheaper than doing it ourselves (amazing, eh?).
2. Replace water heater - We currently rent an old, crappy electric water heater, and will be moving to a high-efficiency gas water heater. In order to direct vent up the chimney, we also need to have a new liner installed, but if that is not possible we will power vent instead.
3. Replace four basement windows - We ordered replacement slider windows yesterday. Two of the windows will be slightly larger than the originals, which will add more light into the basement. We do not need to add an egress window in our basement since we have a direct exit through the side door, and our basement windows are quite large so they easily exceed light/ventilation requirements. We also plan to replace the old milk drop box with a fixed window, which should add a little bit of light into the stairwell down to the basement.
4. Insulate the basement walls and headers - This does not seem like a very tall order, but prior to insulating, we need to break up the basement floor, re-do the drains underneath the house, upgrade the supply line, pour a new basement floor, and frame the exterior walls.

Sooooo, August should be a busy month at our house, especially considering we plan to spend some time in cottage country and I do not want to "waste" any vacation time on renovation projects. Can we get it done? I hope so.

The Future of Framing

I read an interesting article tonight on the Fine Homebuilding web site entitled The Future of Framing is Here. It discusses smarter framing practices that use less materials and provide for significant improvements in energy efficiency. Some of the changes proposed in this framing methodology for exterior walls include:

• Using 2x6 studs at 24 inches on center;
• Supporting window/door headers with header hangers instead of jack studs;
• Using a single stud at rough openings with no cripple studs under the ends of window sills (I definitely agree that there can be a lot of waste when framing windows/doors);
• Framing corners with just two studs (and drywall clips); and
• Placing windows and doors on stud layout and lining up joists, studs and rafters (seems obvious, eh?).

I didn't notice until after reading the article that this was written back in 2005, which is interesting because I had not heard of some of these concepts before (e.g. header hangers). I don't know if all of these framing techniques are permissible by code (not even sure of a good place to look up code requirements in Ontario?), but the argument for better energy efficiency is convincing.