Tuesday, April 20, 2010

Monolithic slab foundation

A lengthy follow up on my last post. I have re-applied for my permit (my 1 year is up) only to be denied. My heart sunk. What would I do? It turns out 6 months ago they changed the rules and it is not permissible to build the garage before the house. So I have to get a septic permit first and then apply for a house permit. Not the end of the world, although I thought it was when I first heard the news.

Okay now.... on to excavation. There was no ceremonial first shovel scoop, as there will probably be no ribbon cutting at the finish. Just an enthusiastic me giving the backhoe some simple instructions and poised to fix up any of his mistakes or sloppiness. I was content with putting a little elbow grease into it because it meant I didn't have to have an exact plan yet, and I love flying by the seat of my pants (or in other words I'm lazy and lack foresight).

I soon found my plan. It kind of appeared out of nowhere, shovel by shovel, week by week. Turns out I basically did the excavation by hand. Okay I did some research too. The foundation I am using is called a "monolithic pour". It consists of a thin slab of concrete thickened around the exterior. The whole thing is floating on polystyrene insulation. This method was discouraged by CMHC until they saw scandinavians doing it successfully for about 15 years now. As a result they have provided information on their website. Here are some photos.

This is after the tractor leveled it out and raised some earth in the middle for me.

Now with this kind of foundation it is not necessary to dig below the frost line. I managed to score about 1000 sq. feet of styrofoam insulation from the roof of a building that was taken down. It cost me $300.00 for all. It will give me twice the R value suggested for under slab insulating. On top of that I had to put a vapor barrier and I again found some vapor barrier/foil bubble insulation that I got for free at a tradeshow. This will also help the insulation of the slab. Vapor barrier is used on the warmer side of the insulation so that when the warmth meets the cold, the moisture in the warm air (cold air holds little moisture) will condense and we dont want that condensation to touch, and therefore ruin the insulation.

On occasion I have been told I was wasting money and time putting insulation under the foundation. I believe they were too distracted by my biceps to notice the ace up my sleeve. You see I plan on putting an electric heating coil into the concrete when they pour it. I bought two 400 foot coils which should keep us plenty warm.

Next, comes the wooden forms. I have been told horror stories of wooden forms breaking and having huge concrete messes to clean up. So I over engineered this aswell. It actually took me an entire day just to rip the forms apart after the pour.

Then hired a guy to put in plumbing for the kitchen, water room, and bathroom.

By this time it was late October, the prep had taken me the entire summer on my part time building schedule. I had to leave for Toronto and the forecast gave us about a 2 day window to pour the concrete before the cold. So I bought some flood lights and spent all day and the entire night finishing up with the wire mesh, rebar, and spreading the heating cable. The sun was coming up while I got in my car and started for Toronto for a late morning meeting. I was exhausted, but exhilerated. My excitement kept me going. I showered at a truck stop.

When I returned from Toronto, this is what I saw:

I learned some lessons whilst foundationing.

1. ENDURANCE - Everytime I felt I was in over my head (every stage so far), I would keep the shovel moving while thinking of how I was going to come up with the money to hire a professional to finish for me. After a while I could see my progress and was encouraged and able to continue.

2. I TALK TO MYSELF - Okay, I always knew this, but I'm not sure I've always been so supportive of me. Saying things like "try again J dawg, that rock ain't got nothing on you" or when I had escaped a setback or done something well I would hear myself say " blessings! blessings!". These and many more very interesting conversations. However, I promised myself I would not gossip on myself.

3. I CAN SLEEP ANYWHERE - damp trailer on a stormy night, bottom of dirt hole, boulder overlooking lake, bottom of canoe floating in the middle of the lake.


5. I HAVE CHATEAU COLOURED GLASSES - All the advice I have received have been "good enough" anecdotes. They all clash with my vision of grand. Trouble is when you over engineer one thing, I've learned that you over engineer everything for fear you are creating a weak link in the chain.

Almost done........

Cost so far:

Excavation including 8 trucks of gravel - $1100
Insulation - $300.00
Wood for forms - $50.00 (thanks Paul Desousa)
Screws - $30.00
Vapor barrier insulation - $0.00
Rebar and wire mesh - $450.00
2 Heating coils and 2 smart thermostats $800.00
Concrete and labour - $4200.00
Ferry fees and tools and lunch and misc. - $400.00
vibrating plate/earth packer - $45.00
2 bales of straw $60.00

Cabin total so far: $7435.00

With snow looming on the horizon I had to protect my investment. I pulled my trailer to a farm and asked to buy 2 large round straw bales. He loaded them with his tractor and they just barely fit. With some help from Ryan Palmer we rolled them up onto the foundation and spread it to about 1.5 feet thick, covered that with tarps, and hoped for the best.


Jessica said...

And was it ok? Did it survive the winter?

Daddy E said...

you'd better believe it baby. Not a crack.......yet. It took me a whole day to shovel that straw off cause it was wet. I originally wanted to burn it but because it was wet I ended up wheelbarrelling it down the hill. I may have a pic.

D said...

Oh man this is good stuff. Keep the details coming. When you hear that voice saying that you are man, it's really me saying it from 3200 km away.

What are the dimensions of this monolith? It's hard to get a sense of scale from the photos.

Daddy E said...

Thanks man. The dims are 25'4" x 31'4". It was supposed to be 24x30 but I added the extra 1.5' each way so not to lose interior space when I build my 8" thick square log walls. Turns out I didn't need to account for the square log walls. I'm going with a full log Scandinavian scribe (Another whimsical plan change). This makes that extra room on the slab very valuable since they are monster logs!! I'll post it soon.

Wendy said...

Cool post... great read.