Feb 082017
 

I wish I could show you a photo of the house today. It is buried in snow. Unfortunately, Leanne’s computer is still too full and I can’t download the photos from the camera yet.

This photo from New Year’s 2017 will have to suffice.

January 1st, 2017 at 12:43 am.

We thought this was a lot of snow. (Ha!) Besides less snow, the other thing that is different in this photo is all the lights are on.

Over the past weekend, due to heavy snow breaking branches, we have had 6 separate power outages.

They are not the most relaxing events, but the kids love a good black-out. We light candles and revel in the adventure. “I love Earth-hour!” says my daughter.

Beneath the fun of it lies my worry that the decisions we have made on the house leave us vulnerable to power outages. Specifically, back-up power.

I have this insecurity that there is a silent mass of onlookers waiting for us to fail. “Let’s see how this ‘Forever House’ handles a power outage” they say in my head. “Bet they wish they had a gas generator!”

Well, I must admit it was a bit shaky, but we did okay and I remind myself that we’re not done yet.

Surprising to many, my master plan calls for no fossil fuels and no wood-burning. I want to keep the brick fireplace but insert an electric fire that looks good and gives a little heat. When the power went out, however, it was very comforting to be able to light a fire. It reminded us of the winter of 2014 when we challenged ourselves to live without buying more fuel oil and so we relied on wood and a little electric heat.

Leanne wants to keep the fire, but we don’t have to decide now, because we have a lot of other things to do before we come to that.

The fact is, we moved in before the house was done. I am not finished insulating and sealing the basement and top floor. The root cellar door is not sealed and insulated as well as we plan to. I’d also like to re-apply the weather-stripping to the windows, seal up the stained-glass transom lights in the front rooms, and improve the front door.

All this insulation and sealing is key, because we are counting on it to keep our heating bills down.

At the moment, our heat is supplied by the same water heater that used to heat our tap water before the renovation. Hot water is pumped through pipes stapled to the underside of the main floor and it warms the floor above.

Heating water with electricity is 100% efficient, but it is expensive, so I have been steadily trying to finish insulating wherever I haven’t reached yet.

The first time the power went out for more than an hour, I was anxious that putting our eggs in the electricity basket had been unwise. However, we noticed that the house did not cool very quickly. The insulation we had done so far was having an effect. It was the front rooms with their thinner walls and heritage windows that cooled the fastest and that’s where the fireplace was.

I also noticed that the bathroom floor, where the water heating pipes are embedded in concrete just below the tile, stayed warm for two hours or so. I realized that one great advantage to heating with underfloor hydronic pipes is that once the water is warm, it continues giving off heat for some time.

Once the house is finished, we will be able to last a long time without feeling the chill, but maybe you still think we need a back-up source of heat for longer emergencies. They tell you to be prepared for 72 hours without assistance.

My answer to that is my father-in-law Dave’s idea which he has helped us implement: the Toyota Prius as back-up generator. Read more about how we’re doing that here. When the wiring to the garage is complete, we can use the Prius or any other hybrid or electric car to power important stuff in the house like the fridge.

A more obvious solution is a large storage battery like Tesla’s Wall. Charge it in the daytime with solar panels and charge your car from the battery at night. If there is not enough to completely charge the car, BC Hydro will tip it up.

Incidentally, this is the same principal we hope to implement with the solar hot water panels someone handed down to us: heat a large tank of water in the heat of the day and use it (or simply let it warm the basement) in the evening.

It seems I have to get used to the idea that the house will be completed bit by bit. There will probably not be a ribbon-cutting ceremony. That fantasy of moving back in with all systems working perfectly is just that, a fantasy.

Meanwhile, it looks like it will be sunny tomorrow so the kids will go back to school. Then, later in the day, another winter storm is expected. At least now we know we can handle it.

Oops, we’re a little low on dry firewood…

Anybody got some?

 

 

 

Nov 122016
 

Does Donald Trump’s victory mean the end of Climate Action in the United States?

Does it mean the end of the Paris Accord?

Does it really mean that half of the American people think that Climate Change is a hoax?

I don’t know about the first two, but I can’t believe people who voted for Trump don’t understand that Climate Change is a thing that we have to do something about.

Some of them, maybe…

I suspect they are mostly sick of having it pushed in their faces as if its their individual problem to solve.

Leanne and I can relate.

img_2865At this stage in our renovation and retrofit we’re just trying to finish enough of the house so that the building inspector will let us occupy it and we can get homeowner’s insurance again.

We’d like to spend Christmas in our house for a change instead of next door.

I haven’t been writing the blog because I simply don’t have energy at the end of the day. Weekdays I wake up early to make lunches for the kids, teach a class til noon, pick the kids up from school, and then work on the house til dinner time. Leanne works full-time and keeps up the electrical work with our electrician and her Dad. On weekends its all house all the time.

If this is what it takes for average folks to fight climate change, its no wonder we’re the exception, not the rule. My Eco-Warrior Badge is heavy.

Trump often railed against “the Mainstream Media”. Apparently, it struck a chord. Maybe when you are  struggling to eek out a living and the media reports that climate change is the single greatest threat we face, it’s a little hard to swallow.

The truth is that the media have been under-reporting climate change. There is no confusion among scientists, researchers, NASA, the UN and everyone else who has looked at it for ten minutes but nobody seems to have any solutions besides buy more eco-friendly stuff.

One problem is that most mainstream news is delivered in a context of commercialism. Every story is steeped in commercials for stuff we don’t need and the solution for climate change is presented in products. Buy a more expensive car to reduce emissions. Replace lightbulbs, shop local, buy organic. The market has consumed environmentalism as an opportunity to sell more stuff and that has made everybody cynical.

CBC radio had a story on today about some people who say that Canada should reconsider its commitment to introduce a carbon tax.

Wrong! A carbon tax is precisely the kind of tool we need!

The BC example has been good for the economy while reducing greenhouse gases. It provides incentives for communities to take climate action which takes the pressure off the individual consumer who is already wracked with guilt for buying a new…anything.

What will happen if the US stops taking action on climate change? Will Canada’s economy suffer?

Can I answer that question with a question? Can we stop thinking about the profits of large corporations as if their well-being is more important than anything else for a second?

The Natural Resources minister under Stephen Harper, Joe Oliver was on the radio programme I was listening to. He was so full of misinformation I was yelling at the radio.

One thing he said was that the best way to fight climate change is to push forward in science and technology so that cheaper and better ways to solve the problem come into the market.

Sound reasonable? It’s hogwash. What makes me angry is that he is in a position to know better. All the best information was at his fingertips, but he continues to soothe the shopping public with the message that we can keep doing what we’re doing until technology fixes everything.

One of the biggest lessons we have learned as we work to make our home as energy-efficient as possible is that technology is not the issue.

The technology and techniques have been around a long time and they are so simple that most people can understand easily:

  1. Insulate your house
  2. Insulate your house some more
  3. Insulate your house to the point where people look at what you’re doing and say, “holy crap that’s a lot of insulation”
  4. seal your house (doors, windows, chimneys, vents…)
  5. ventilate your house (you need fresh air now that you sealed it so well) with a Heat-Recovery Ventilator

Now that you have done all that you should not need very much heat in the winter nor cooling in the summer. Now you can decide how you want to provide that little bit of heating and cooling. (Hint: try not to use fossil fuels, including Natural Gas)

Here are a few fun options for heating your house without emitting GHGs: an air-source heat pump, a ground-source heat pump or a sun-pump.

SPOILER ALERT: Leanne and I have decided to deliver heat in the house with water pipes under the floors (and radiators on the top floor) and heat that water with electricity. We’re eschewing a heat pump for the time being but we may be able to partially heat the water with solar panels.

Yes, there are best-practices and some gadgets which help with all this, but the technology is available.

The problem is that not enough people are doing it.

Why are solar panels expensive?

Not enough people are buying them.

Why is it so hard to find a contractor who knows how to retrofit a house?

Not enough people are doing it.

Why does it take so long to retrofit a house?

Not enough people are doing it.

Does this cycle right back to blaming the public for not taking action? No. How can we expect the 99% of people who are not rich to spend a year and a lot of money retrofitting their house when the return on investment will be at least a decade away?

So, let’s not blame the media for ringing the climate bell without offering solutions. The solutions have to come from the people we elected to manage our future. Unfortunately, I don’t think Donald Trump has any solutions and I pray that Canada stays strong and doesn’t get sucked into the past.

Til next time,

James

 

Oct 012016
 

Ever since the spray foam was…installed? Is that the word? Sprayed? Anyway, ever since then, we have been working flat out roughing in electrical, building interior walls, building the basement stairs, putting a skin on the outside of the house and on and on.

imageIn the mornings I am back at ISSofBC teaching English to new immigrants and in the afternoons I pick up the kids and work on the house. I’m so busy I haven’t had time to share some significant events with you: the spray foam installation, the stairs, presenting at our MP’s townhall on Climate Change, to name just a few.

We’re finally nailing down the details of how we will heat our house–with water, as it turns out–and I remembered from my experience putting hydronic please pipes in the basement slab, that the City will probably want a heat-loss calculation done. That will show how much heat will be lost from each room of the house to ensure that the system we put in will meet that need.image

A Heath-loss calculation is not something I can do, so I asked Richard from Meadowridge Plumbing to get one done.

I think that these calculations are usually done assuming standard insulation values and I didn’t want that. We’re going far beyond the minimum in some places and if we use standard values it might mean installing a heating system far bigger than we need. For example, minimum wall insulation in Maple Ridge is only R20 and there will be R50 in some of our walls.

I thought it would help if I marked how much insulation will be in the walls and ceiling on a plan. Here’s what I came up with.

On the top floor, the spray foam gave a minimum of R28 to all the ceiling space. Wherever I can I will add more batt insulation below that. The number will vary based on the size of cavity–those attic spaces are triangular.

image

On the main floor the R-values vary in the roof spaces again and you can see that the front two rooms of the house will remain at R14 because we cannot add insulation in those walls due to heritage considerations.

image

Check out my previous videos to get an idea of what’s going on in the basement. It’s a little confusing from the drawing…

image

PS I always imagined this blog could be a play-by-play of our project as it proceeded but it looks like I will have to tell much of the story in detail later in retrospect. The story is complex and sometimes requires careful wording which takes time. Every moment I am not working on the house keeps my family out of our home for longer, so please accept my apologies if I paint an incomplete picture.

All will be revealed, I promise.

 

Aug 192016
 

On the same day I took the video of the basement insulation, I took this shorter one.

We’ve had two days of Element Spray Foam parking their trailer in the back yard and running their hoses into the house to coat the ceilings with upside-down snow drifts.

Can’t wait to share some of that video.

In the meantime, I wanted to show you what the back deck, sunroom, kitchen, bathroom and pantry looked like before the foam changed everything.

Enjoy!

Aug 172016
 

The kids are at summer camp this week so I’m tiring myself out working on the house.

Soon these walls will be 6 inches thicker

Soon these walls will be 6 inches thicker

Tomorrow Element Spray Foam is coming to insulate the house! It has been a lot of work to get ready for this day and I haven’t had time to write.

That’s why I thought I would shoot a video for you.

In it I show you around the basement and explain where the spray foam will go and how we’re insulating the walls down there.

I also demonstrate how tired I am!

Please remember that I am not an expert so if you are interested in doing something like this, make sure you get professional advice before you proceed!

Aug 062016
 

I haven’t made a time-lapse movie in a while.

I made this one on Thursday afternoon working in the basement. It’s important because I can finally show you what is going into those walls.

In this first video you can see me struggle to get the top-plate in above the 2X4 stud wall I built and then start insulating behind it.

I framed the interior wall on May 10th.

I framed the interior wall on May 10th.

That was the first wall I’d ever built. Our Rescue Contractor (He Who Fixed The Structural Issues Left Us By Another Contractor) taught me to build the wall flat on the floor, then lift it into place and attach it to another 2X4 attached to the ceiling (called the top-plate). I did that three months ago and then got distracted by more urgent tasks.

In the meantime, the electrical team (Leanne, her Dad and Golden Ears Electric) went ahead and roughed-in the wiring. That made it more difficult to get the top-plate up there.

Notice the stripes of sealing foam I had already added around the edges of the exterior sheathing. That was a tip from Walter.

Here is a play-by-play:

-James slides top-plate into position and balances it on a board so he can screw it up unassisted (he is screwing stuff up unassisted a lot lately)

-James notices that a wire is on the wrong side so he pulls out the top-plate and tries again.

-James notices that another wire is on the wrong side so he pulls out the top-plate and tries again.

-James puts two screws through the top-plate into every ceiling joist, careful to avoid the wires running through the joists.

-James uses a flashlight to confirm that yes, he put a screw right through one of the wires running through a joist.

-James curses, marks the damaged wire, and considers how to apologize to Leanne who is going to have to replace that wire.

-James uses a hammer to bash the top and bottom of the stud wall into place under the top-plate because he didn’t leave that 1/4 inch space that contractors always say you should leave.

-James grabs some Roxul batts from the huge pile that was taken out of the attic and has been cluttering up the basement for months and starts fitting it into the spaces in the exterior 2X6 stud wall.

-the battery dies.

We’re finding it very helpful to have short-term goals to work toward. A big one lately is the spray foam. That’s the kind where the people in space-suits show up with a van and hoses. We’re planning to fill the rafters under the roof with about 5 inches of 2-pound spray-foam insulation and there are a number of things we have to do before that can happen.

In the basement, the spray foam is going only into the rim joists–sometimes called box joists–which are the spaces at the top of the basement walls between the ceiling joists. It’s very difficult to seal and insulate those spaces, so spray foam is a good idea in there.

The walls, however, are easy to insulate so you can save money on that expensive (and not so environmentally-friendly) spray foam.

Shout-out to Monte Paulsen again because I am finally following through with his advice for an inexpensive super-insulated wall.

The building code requires new construction to have 2X6 stud walls instead of 2X4s. That means a thicker wall that can be insulated better. Roxul batts that fit 2X6 walls have an insulation value of 22 (R22).

However, the building code is only a minimum standard. Once you have your 2X6 wall and the structural engineer has signed-off, you can make your walls thicker. It’s easy!

More than simply adding insulation, you can interrupt the heat transferred through the wood studs in your wall. This is called thermal bridging and I am obsessed with eliminating it.

With Monte’s idea of adding a 2-inch thick sheet of styrofoam between and then building another wall inside it, the heat can’t use the studs as a bridge. On the inside of the interior wall, a sheet of plastic keeps the moisture in the warm interior air from getting into your walls. Over that goes your gypsum drywall.

Since the Rescue Contractor and engineer have already made sure the house is structurally sound, I’m free to fumble around learning how to build walls without worry. (I like to think the Rescue Contractor is very busy and has faith in me and those are the reasons he didn’t return my texts when I wrote to ask if I can publish his company’s name.)

And space? Yes, we will lose about 6 inches of space around the exterior walls, but after a week we won’t notice anymore.

In the second time-lapse, taken after I plugged my phone in, the sun goes down as I gleefully insulate.

There are two parts to this wall: the concrete and above the concrete (AKA the pony wall).

The concrete has almost no insulation value (and, if you remember, I didn’t consult with Monte in time to know we could put Terrafoam rigid insulation under the footings–a nagging regret.) On the outside, under the ground level, is 2 inches of EPS styrofoam with an R-value of 8. Above the ground the concrete is bare until the shingles start.

The basement wall below the ground will be insulated like this:

2″ Exterior styrofoam (insulation value R8)
Concrete (R0)
2″ Interior styrofoam (R8)
Roxul batt in 2X4 stud wall (R14)
Total: R30

In the wall space above the concrete foundation–the pony wall–there are three types of insulation. There are Roxul batts in the 2X6 stud wall, Roxul boards and styrofoam. Roxul board is the product I told you about which fits perfectly in this unexpected inch-and-a-half space between the 2X6s and the styrofoam. The white EPS styrofoam is much, much cheaper than the higher density blue or pink rigid foam insulation you have seen around. It has a lower R-value, but is less carbon-intensive to produce. Finally, the interior stud wall will be insulated with more Roxul batts.

Looking at insulation value above ground we get this:
Roxul batt insulation in the 2X6 wall (R22)
Roxul board (R6)
Standard EPS white styrofoam (R8)
More Roxul batts (R14)

That makes for a total insulation value of R50 when the wall is finished. The shingles outside might even add a little more.

Incidentally, you can buy all these insulation types at your local building supply

Inside Plastifab's local facility. Photo taken without permission (I hope they don't mind!)

Inside Plastifab’s local facility.

store, but I went straight to Plastifab for the EPS styrofoam. I bought a lot of that stuff!

Ask the Rescue Contractor how much I have been looking forward to insulating those walls. Every time he added another 2X6 to a wall to make it stronger, I would whine about thermal bridging.

That’s why I pushed through dinner and, at 9pm, Leanne showed up with some sushi leftover from her dinner meeting.

I don’t know if you can tell in the video, but she forgave me for damaging her wire.

Afterthought: watching me cut up that styrofoam into little pieces to fit it between the studs, I think you can see how much more sense it would make to insulate the pony wall and add the styrofoam in big sheets before building the interior wall. The building inspector is going to let us do that with the rest of the walls instead of insisting all the electrical work is done before inspection. Thank heavens for flexible officials!

Jul 042016
 

Things I found while working in the attic today:

Treasures

Treasures

It’s a dirty, dusty place to work, but it’s rewarding when you find…a hammer? No, not the hammer. I’m using the hammer to build stuff. What is that next to the hammer, though?

It’s made of wood and I think it’s some kind of target. Leanne’s Mom, Julie, has an older brother, Uncle Jim, who also grew up in this house. We’re pretty sure all the pellets embedded in the garage door are from his pellet gun. This target looks none the worse for wear so either it was not that kind of target, or Uncle Jim was a terrible shot.

Even more interesting than the hammer or the target is that little piece of paper. Check it out:

Anyone know the restaurant?

Anyone know the restaurant?

That’s right. An old-school fortune from a fortune cookie circa…? And a very wise one, at that. I’m certainly learning a lot, but I’m not feeling particularly young.

So what am I doing in the attic? Making the walls, floor and ceiling thicker to accommodate more insulation of course! Here is the before and after.

Before:

DSC04014

After:

Thicker roof rafters, thicker floor...

Thicker roof rafters, thicker floor…

This is the attic space above the front porch, so the more insulation I can add, the better. The roof rafters for this gabled dormer that sticks out majestically over the porch are only 2X4s. I’m adding another set of 2X4s so that we can fill up that 7 inches of space with 5″ of spray-foam insulation and 2″ of something else.

The house on July 4th with its gabled front dormer and diamond window into the attic.

The house on July 4th with its gabled front dormer and diamond window into the attic.

Speaking of insulation, on the floor of the attic is a treat for us energy efficiency geeks: the original bags that the rock wool insulation came in have been used as an underlay.

This slideshow requires JavaScript.

This slideshow requires JavaScript.

Jun 212016
 

Flashback to December 11, 2013 at 4:59pm.DSCN1534

Two chimneys: one for the oil furnace, one for the wood-burning insert in the fireplace.

A light dusting of snow melts soonest where the 2X6 rafters are all that lies between the warm air of the kids’ bedrooms upstairs and the roof. They show like ribs on a feverish, bedridden child.

DSCN1535

At the back of the house the cat door leaks heat into the neighbourhood. Among the clearly defined rafters are splotches of dark where the snow has melted around the plumbing and  roof vents as well as above the joint between the original house and the shed addition.

Between the rafters in these photos–under those rectangular blocks of snow–is fiberglass batt insulation. Its insulation value is probably about R14.

As we get ready to fill the roof rafters of the newly renovated house with insulation, it’s important to look back and see what we’re aiming for. R28 spray foam insulation plus an addition of approximately R14 batts. DSC03911

That makes R42–an R28 improvement over the old house.

This winter, and in every winter from now on, when it snows on Hammond Forever House, all you will see on the roof is snow. I like to think it will take the sun and a warm day to melt it off.

Jun 122016
 

Back in December, we made a couple of new political contacts.

John Horgan, James, Leanne,

John Horgan, James, Leanne, and George Heyman in The Little Yellow House

They were John Horgan, MLA for Juan de Fuca, Leader of the Provincial NDP and Leader of the Opposition in Victoria as well as George Heyman, the MLA for Vancouver-Fairview and the Opposition Spokesperson for the Environment, Green Economy and Technology.

Continue reading »

May 222016
 

After compacting the crushed rock in the basement, it was time to do something I’ve been waiting years to do: put styrofoam under the basement floor.

Does that sound crazy to you? Well, it’s one of those things that soon everyone will be doing, especially in colder climates. Let me put your mind at rest on a few points:

A stack of 3" Terrafoam sheets sit on the Terrafoam floor. Note the perimeter of foam around the walls and post bases. We made long cuts with a hand saw. Easy.

A stack of 3″ Terrafoam sheets sit on the Terrafoam floor. Note the perimeter of foam around the walls and post bases. We made long cuts with a hand saw. Easy.

1. Too bouncy? Worried the concrete floor will sink or shift if it’s resting on foam? The rigid foam we used, which is called Terrafoam and is made by Beaver Plastics, has a greater compaction rate than the soil that is under it. It is solid. That’s not just me saying that, that’s our engineer. Even standard, white, EPS which is that white stuff that we see in packaging all the time, is used in big engineering projects like embankments under highways. In fact, I learned too late that we could have put foam under the footings of the house for maximum effect with no structural issues. Oh well, next time!

We used a table saw to cut the edge pieces to separate the concrete slab from the wall.

We used a table saw to cut the edge pieces to separate the concrete slab from the wall.

2. What if water gets under the house and floats the floor up? That was a story someone told us. Well, if you put blocks like they put under highways–great 2 meter by 8 meter ones–under your house, maybe this could be a problem. However, even as much as 12 inches of styrofoam under your house should be fine.

3. Why bother? Some people say the energy savings aren’t going to pay for the extra time and money to put foam under your house. In this housing market when every homeowner is thinking about selling, I understand this perspective. But when you think 40 years down the road and you remember what we’ve learned about the greenhouse effect, it is totally worth it. An efficient house uses less of everything that is warming the planet.

This whole idea came from Monte Paulsen, our energy advisor from Reddoor Energy Design. In February, 2013 he gave us his notes on the HOT2000 energy model he had created.* I’ve had that long to get used to the idea. He wrote:

So, if you’re going to build a conventional foundation, what’s the most cost effective way to insulate it?

Consider adding a “U” of foam insulation that runs down the wall, under the slab, and back up the opposite wall. This arrangement separates the slab from the wall, so the slab can work as thermal mass inside the envelope.

The upgrade model assumes six inches of EPS foam (white Styrofoam) under the slab (R-24) and two inches of XTPS (pink or blue foam) along the perimeter of the concrete (R-12). Inside the XTPS, the model assumes a 2×4 @ 24” wall with R-14 batt (eg, Roxul) insulation and GDW.

DSC03089Can you picture that? You have to remember that your footings and foundation walls were poured first and your basement floor is going to be a separate chunk of concrete poured on a different day. First walls, then floor.

Concrete transmits heat quite well, so if you pour your basement floor without separating it from the walls, any of the heat that is in the room can go into the floor and escape through the walls and footings into the ground.

If the floor is suspended on a bed of styrofoam and doesn’t touch the walls, any heat that is in it can’t escape so easily.

Monte’s model assumed six inches of EPS rigid foam under the slab (floor). Discussing it later, we upped that to 12 inches. Now you know why I was disappointed that we could only fit 3 inches because that was as deep as the storm sewer would allow.

Everyone said that 3″ was plenty. The temperature doesn’t vary much that deep in the earth, they said. You’re only required to put foam around the edges of the slab, they said. You don’t have to do that, you know, they said. The most helpful of these comments was from the Maple Ridge Building Dept:

Not to sure where the trade off is but 12″ of insulation under the slab strikes me as being excessive for no real gain. Below frost the ground maintains a consistent temperature which I believe is around 5 degrees so thermal conductivity through the slab‎ is minimal. Unless you are doing radiant in floor heat the better places to increase R value are the walls and ceiling plus looking at ways to eliminate thermal bridging.

Well, as you know, we did end up doing radiant in-floor heat, but that is another post.

Meanwhile, Monte was working on sexy new Passive Houses where that much under-slab insulation is routine. It really is a case of short-term thinking. If you are not going to profit off it in the next five years, conventional wisdom says you shouldn’t do it. Conventional wisdom has its limits.

Upon further discussion with Monte, I settled on 9″ of white EPS or 6″ of Terrafoam, which is a newer EPS product and insulates better. Since his 2013 report, Monte has pointed out that XPS, the blue or pink rigid foam you see around a lot, has a very high carbon-footprint in its manufacture, and he has stopped recommending it from an environmental standpoint.  For this reason I decided not to use it in the walls.

I settled on 3″ of Terrafoam because every extra inch meant raising the house by that much more. This was one of the compromises we made between heritage, economic and environmental considerations. I still feel like I didn’t get the accurate information from our contractor that I needed to make this decision. I mean I have a sneaking suspicion we could have put more foam under the slab somehow.

Among our graffiti is Dave's birthday wishes to his wife, Leanne's Mom, who grew up in this house.

Among our graffiti is Dave’s birthday wishes to his wife, Leanne’s Mom, who grew up in this house.

With 3 inches of Terrafoam and its insulation value of R-5 per inch, we ended up with R-15 under the slab. The BC Building Code says you must have a minimum of R-13 under a heated slab, so we were okay.

With no contractor working with us, I set about laying our 3 inches of Terrafoam, keeping in mind we wanted a 4 inch deep basement slab. We always intended to do this type of work ourselves, but it was a little nerve-wracking not having professional advice as we proceeded toward our first independent building inspection.

Our contractor had left a chalk line on the walls showing where the top of the basement slab should be. I decided to trust this line was accurate which saved me renting a laser level and figuring out how to use it.

It was frustrating to discover that often the space between the chalk line and the top of the footing was closer to 6 inches instead of the 7 we needed for foam + concrete. Can I blame our contractor for that? I don’t know. I do know it took more time to lay the Terrafoam because I trimmed some of the edges to fit the uneven and too-high footings. (You can see me doing this in the time-lapse videos.) Would it matter if the concrete were a little thinner around the edges of the slab? Probably not.

The sanitary sewer sump was a challenge. You can't use the canned spray foam to fill in gaps because it dissolves EPS foam like Terrafoam.

The sanitary sewer sump was a challenge. You can’t use the canned spray foam to fill in gaps because it dissolves EPS foams like Terrafoam.

Tips for laying Terrafoam:

It cuts super easy. You can cut it with a table saw if you need thinner pieces, but use a hand saw (or a circular saw, I suppose) if you’re cutting a big piece.

Wear a dust mask because, you know, there’s dust, but don’t worry because it’s not toxic or itchy.

Cut the pieces a little big so they snug together nicely with no gaps.

Don’t compromise! Separate everything from that slab! Put foam around any plumbing or structural stuff that pokes up through the floor.

Umm, that’s it! Any questions?

Ready for the next step: plastic vapour barrier!

Ready for the next step: plastic vapour barrier!

*I shared Monte’s complete report in this post if you’re interested in the whole thing. It’s near the bottom of the post.