Friday, July 30, 2010

Insulation: There is more than just the pink stuff

Insulation.... ahh the sexiest of home renovation topics. Alright, it can't compete with cabinets or flooring. Heck even faucets look exciting in comparison, but when it comes to a green renovation, insulation along with sealing your home envelope are the meat and potatoes.

With insulation, it all comes down to R-value. R-value is essentially the “Thermal Resistance” of a material. The higher the number the harder it is for heat to pass through. Seeing as this is the job of insulation, R-value along with price are usually the deciding factors in picking your insulation.

There was a period when fiberglass insulation was the beginning and the end of your home insulation choices. Nowadays, it is part of a subcategory. The list below is by no means exhaustive, but it covers what we felt were viable insulation options for our project. If you really want details there is a pretty good insulation guide put out by Natural Resources Canada.

Batt insulation: flexible insulation that fits between the wall studs. This includes traditional fiberglass but also the awesomeness of Roxul. Its easy to install and typically the least expensive.

Spray foam: A spray on insulation that provides not only some of the best insulating power per inch but also acts as an excellent air/vapor barrier. Can be expensive and for any significant job requires an outside contractor. Small jobs can be done by DIYers like we did behind the fireplace.

Rigid Insulation: Rigid foam panels. Again increased R-value and eliminates thermal bridging but can be expensive.

Now, if you didn’t catch it above, I am a fan of Roxul. So much so that it makes me wonder why you still see so much pink stuff in Home Depot’s aisles (Roxul is green). Roxul is made from stone wool: essentially rock and recycled slag spun into fibres. The result is a product that is:
  • Easy to handle, cut and install

  • Offers great R-value: R-14 vs. R-12 for fiberglass (although in writing this I have discovered both a new Roxul and new fibreglass rated to R-15)
  • FIREPROOF! (it is rock after all, and I guess officially it is only fire-resistant as it will melt at 2200 degrees F)

  • Made from 40% recycled material
  • Minimal additives, no off-gassing, etc

But for our project we needed more than just Roxul. For LEED certification we needed a minimum of R-20. Since our exterior walls are 2X4 construction we identified three options to get us over R-20:

Option 1: Spray insulation between the studs: R-24.5
Option 2: Build up the wall 2” and use 2x6 Roxul: R-22
Option 3: Use Roxul in between the 2x4s and add 2” of rigid insulation: R-24

While they all seem to be in the same ball park performance wise, the R-values above are just for the insulation and do not account for a phenomenon called “Thermal Bridging” . Say you build a beautiful 2x4 wall and have it all nicely insulated with R-24.5 spray foam. That is great but the wood studs conduct heat too and they only have an R-rating of 4. So they act as a “bridge” for the heat to pass through. If you take this into consideration then the R-value for the wall is: 17.1 (I will not bore you with the equations). Looking at the R-values for the wall, the revised numbers become:

Option 1: R-17.1
Option 2: R-19.5
Option 3: R-22.6

Option 3 has the rigid insulation that covers the studs and thereby eliminates part of the thermal bridging explaining why it performs better. The above calculations also are for standard framing (a stud every 16”), if you were to account for all the extra lumber around the windows and doors the performance gap between Option 3 and the others would get even bigger.

Wow…that was a very long lead into to explain that we are using R-14 Roxul with 2” Styrofoam on top:

First step was to cut and fit Roxul into all stud openings. It cuts great with any serrated knife (just don't tell Jody that I used one of our good kitchen knifes).

Electrical boxes neede to offset 2" to account for rigid installation. They also need vapour boxes around them with electrical connections taped off. This prevents air and moisture from passing through the box. It is also the reason most older homes have drafts through the outlets in the winter time.

The rigid insuation is then intalled.
It is screwed on to the studs using recessed washers. Then all the vapour boxes are sealed and taped flush with the styrofoam.

So what does the mean for our LEED points: nothing really yet… First off we have only insulated 10% of our house so we haven’t met any criteria yet. And we do not get points for the insulation itself but rather the overall efficiency rating of the house (which is big points: up to 28 but we are hoping for 10). When complete, we are also hoping to get a half point for recycled content in the insulation.

Saturday, July 24, 2010

Our Blog Logo

If you have been to the blog before, I am guessing you picked up on the change to the layout.

The new logo at the top of the page is courtesy of our 5 year old son. He had fun going through the deconstruction leftovers looking for materials. If being used in crafts qualifies as waste diversion, he has certainly being doing his part.

I need to try to find a better background to put in on but right now we are two weeks behind schedule (&%$# fireplace) so I am off to insulate.

Saturday, July 17, 2010

The Fireplace: Round 2

Some of you may remember our fireplace dilemma. There were two issues with our existing fireplace:

- You lose out on 2 LEED points for having a traditional wood burning fireplace

- We need to ensure that the wall between the fireplace is properly insulated and sealed

In the end we decided to keep the fireplace but we will upgrade to an EnerChoice certified natural gas insert. We viewed it as a good compromise between the charm and appeal of a fire while reducing the air pollution caused by a wood burning fireplace. Montreal city and some of the surrounding towns have banned the installation of wood burning fireplaces and stoves based on studies that show 50% of the city's winter smog is generated by residential wood burning. It didn't feel right to build a green home that contributed to that stat.

That decision though didn't help us with challenge two: the insulation. And that was the one that had the potential to derail the project. A couple of exploratory holes revealed both good and bad news:

The bad news:
  • no insulation
  • no air barrier
  • no vapour barrier
  • and the wall cavity was filled with bricks.

The good news:

  • The wall cavity behind the fireplace was framed like a door with a header beam so we were dealing with one large space instead of three or four little ones.
  • The fireplace was not physically connected to the outside wall
  • the bricks within were not structural (no overhead load). The space actually seemed like there dumping ground for excess bricks and mortar.
So we decided to start removing bricks. This started off fairly simply with the top layer installed with little to no mortar. It is probably a good thing this started off well otherwise it may have ended there. I was able to easily create an opening 8" wide and began working my way down.
It went pretty well until I got about half way down the wall and ran in to a section that was well mortared. If you have never taken anything brick apart it is fairly straight forward. I just had a cold chisel, 3lb sledge and a crowbar. You find the brick you want to remove, you put the chisel between it and the neighbouring brick give it a couple knocks with the mini-sledge and pry it off. No problem.
Where it becomes a problem is when you are trying to remove bricks in a space that is 40" deep and only 8" wide. As reference my arms are only 30" long.

When I had to remove the far bricks I couldn't use the chisel but had to have the crow bar take over chiseling duties. This worked well when it was loose but was a nightmare when the bricks were well set. To further complicate things the wall is to my left while I was working which meant after the half way mark I could only use my left hand for swinging the hammer.

It was a challenge but several hours and two blood blisters later, the wall was empty and I had a giant pile of bricks.

Just like the rest of our Kitchen Deconstruction, I wanted to ensure that as much of that material wasn't ending up in a landfill. So after seveal more hours of work we had:

  • 120 re-usable bricks
  • 242lbs of mortar (re-usable as in-fill)
  • 98lbs of partial or damaged brick (to be re-used as decorative mulch)

But we also still had a large empty wall cavity. Because of the shape and size, we would be challenged to get both traditional insulation and vapour barrier installed and properly sealed. So we opted for spray foam.

There will be times during the renovations that we bring in professionals to apply spray foam. But we weren't calling in the pros for 30 square feet. Instead I picked up the Touch n' Foam professional series kit at Rona. I will admit that I felt very hypocritical buying this one-use-wonder after my "Great Stuff" post.

But it worked. It needed to be applied in two inch layers and allowed 20 minutes to set. But it actually worked really smoothly. It didn't take long to have a well insulated wall with built in vapour and air barrier.

So was all that work worth it? Actually it probably was. As much as I was cursing LEED throughout the process, they were right. Brick is a horrible insulator and had we gone and insulated our whole house and not bothered to fix the problem behind the fireplace 10% of our total heating bill would have been attributed to that 3 and a half feet of wall.

I stated early on that one of the reasons for doing LEED certification was to keep us honest and I think this is a prime example.

Saturday, July 10, 2010

How our Kitchen will be Green: Vampire Energy

Want to knock 10% off your power bill? On average that is how much power your home consumes not using appliances.

I believe the official term is "standby power" but it also called phantom load or my preference: vampire energy. This is essentially the amount of electricity that is sucked in by appliances, adapters, etc. just from being plugged in. There are two big culprits here:

- Standby features: anything with a clock, a power light or a remote control needs electricity when it is off. The flat screen TV doesn't know your are asking it to turn on via the remote unless there is a powered sensor constantly checking for a signal.

- Adapters: anything that has an adapter on the power cord is consuming power even if nothing is plugged into the other end. Chargers for cell phones and other electronics is the big culprit here.

I took a quick tour of our house and the vampires added up

  • TV
  • DVD player
  • laptop
  • VCR (yes we realize it is 2010)
  • wii
  • stove (digital clock)
  • blender
  • phone chargers (x 2)
  • electric toothbrush
  • clock radio (x 2)
  • wireless modem
  • Dustbuster
  • vacuum cleaner charge station
  • bread maker
  • battery charger

We currently have no kitchen; so no microwave either but that is another common one.

So how do you stop it? unplug! .... but that can be easier said then done. Most people, including us, won't bother unplugging the TV every time they are done watching a show. Luckily, our house already has some switch controlled plugs. Our entire home entertainment system is on a power bar plugged into a socket that is controlled by a wall switch. When we leave the room we flip the switch: no more vampire energy.

Taking this into consideration for our new kitchen we realized that there are several appliances and chargers that we would like to leave plugged in for convenience sake but do not want to be drawing power. So the double outlet on the counter and the outlet by the desk with have switches built in.

Not a big change but hopefully it will help stop a little more of the energy drain and save us some money while we are at it. Or as this ad puts it, help us lose an excuse.