100,000 Staples and 26 Tonnes of Plaster and Still Counting

 

 

Back in the day before drywall, also known as plasterboard in the UK or the brand ‘sheetrock’ in the US, interior walls of most houses were lath and plaster. Lath is simply wood strips nailed across wall studs and separated by about a finger space. When plastered over, the plaster oozes through the space and keys into the lath, hooking over the back.

It’s a building method descended from wattle and daub, found in many ancient buildings in the British Isles and European continent, which used sticks and thick cob plaster. My old 1890s flat in Shepherd’s Bush, London, had lath and plaster walls which were exposed when the landlord gutted the place. There’s a good chance the lath was old growth Douglas Fir from the British Columbia coast, which became a major lumber supplier to the UK during the Victoria building boom.

In the post-War period, people stopped building with lath and plaster, favouring the uniformity and speed of standardized sheet goods such as drywall on the inside and plywood on the outside. Time=labour=money while construction waste is externalized to the biosphere so nobody builds commercially with lath and plaster anymore.

Fortunately, we’re building a home with a two-century time horizon not a cookie-cutter commodity to flip or a fly-by-night house built to be chucked in a landfill site like a disposable coffee cup. So, after the big insulation blow we spent a month or three ripping lath, toasting at least one Bosch [all brand no quality action] table saw, and then air stapling it over the entire house inside and out. We even incorporated some old growth Doug Fir lath salvaged from the old 1927 Gabriola Island north end school house, (later the Women’s Institute) when it was renovated into the Gabriola Arts and Heritage Centre in 2016-17.

Once caged in lath, we then began what turned into month long job of applying the ¾” / 20mm exterior base coat of plaster. This is a lime-stabilized earthen plaster consisting of clay dug out of a hole near the garden, coarse sand, a small amount of lime putty and chopped straw. Cheers to Chris Magwood, Jen Feigin, Jacob Deva Racusin, James Henderson and Mike Henry for advice on the mix.

In all we laid on 207 cubic feet / 5.9 cubic metres, or about 11,000 kg, of plaster, one handful at a time. Over this will go a thin earth-lime layer and then a final lime-sand layer. On the inside the base layer is a pure clay-sand-straw mix. The main floor walls sucked up about 282 cubic feet / 8 cubic metres, or about 15,000 kg of plaster. I’m guessing that by the time we’re done there will be about 40-45 tonnes of plaster on the house, inside and out. The final interior surface is a thin finish coat of tinted clay-sand-horse manure plaster. All this heavy lifting was done with the help of many other hands including Kevan and John, who put in many hours, my parents and Karen’s mum and others.

So why lath and plaster you may rightly ask? There are many reasons. We wanted to avoid high carbon sheet goods, especially drywall, which is made from mined gypsum, and the toxic chemicals that go into OSB, plywood, drywall and commercially manufactured drywall mud. Plaster has also allowed us to avoided using an excessive amount of plastic-based vapour barriers and tapes. In terms of performance and good building science, with plaster on both the interior and exterior we’ve created a building envelope that is air-tight and yet vapour open, thus enabling the walls to dry to the inside or outside should moisture find its way into the walls, which is all but inevitable in any house. This ability to dry is one element that separates durable buildings with centuries-long life spans from disposable modern structures often infested with black mould and rot.

We also like the idea of building using as many low-carbon, site-sourced and local materials as possible, which could return to the earth. Lastly, while hard work, plastering is both fun and highly satisfying. The result is a beautiful hand-sculpted wall filled with the texture and joy of the humans who made it.

It’s hard to say that about drywall.

IMG_6617

Starting to lathe the outside

 

IMG_7151

Karen ripping lath

IMG_7899

Sifting site clay

IMG_7900

Making clay slip

IMG_7903

Chopping straw

IMG_7806

Precious lime putty

IMG_7811

North wall earth-lime base coat

IMG_7814

Northwest corner with lathe ready to plaster

IMG_7832

Laying it on

IMG_7852

East wall base coat

IMG_7894

Upper north base coat

IMG_8199

Plaster keying through the backside of lath

IMG_8279

Paintings about to be forever encased in plaster, oh and a pepper

IMG_7906

West side

IMG_7994

Yeah, she’s a climber

IMG_7149

Salvaged old growth Doug fir lath from the old Gabriola north end school house

IMG_8836

Lovely

IMG_8348

Karen and mum going the lounge base coat

IMG_8436

It’s so wee and Japanese

IMG_8483

Lower bedroom finish coat

IMG_8480

Oh yeah, that’s some finish coat

IMG_8831

Plaster colour samples

IMG_8850

If you’ve had a newborn you know what this is. Or it’s plaster.

IMG_8848

Lounge wall.

IMG_8858

When not to do plaster ingredient volume calculations

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10,000 romance novels and the big blow [job]

 

With the crappest job in the world under our belts, we moved on to insulating the walls.

The original plan was to insulate with light straw clay (LSC), as we did with our power shed, which by the way is featured on the cover of the hot-off-the-press Essential Light Straw Clay by Lydia Doleman.

LSC is an outstanding infill material, turning agricultural waste and clay slip into a carbon sequestering, fire resistant insulation that can last for centuries as evidenced by ancient half-timbered, straw-clay wall systems across the UK and northwestern Europe. The downside is the huge amount of work in the volumes we’d have needed and it dries at about 1” per week in summer conditions. So in the end, only being ready to insulate in Nov during the onset of wet winter gales, timing conspired against us.

So what to do?

Pulped fiction to the rescue.

We switched to dense pack blown-in cellulose insulation. ‘Cellulose’ insulation is basically recycled shredded novels, newspapers and office paper mixed with non-toxic borate as a fire, insect and mould deterrent. This stuff is hard to beat. At R 3.8 / RSI 0.67 per inch it’s more than twice as insulative as LCS or straw bale, which are also cellulose but with fewer air pockets and thus less insulative. Blown cellulose reuses a land-fill bound waste product and it sequesters carbon, which is vital to minimizing the embodied carbon and climate change contribution of our house. It’s also very fast to install and when dense packed it also slows air movement through walls while managing moisture very well.

We stapled and lightly glued agricultural floating row cover to the wall studs and then blew and blew and blew. In a couple of days we’d pump 247 bags into the walls – some 2790 kg of recycled paper. On the main floor with the 16” insulation cavity this gives us about R60 / RSI 10.57 and upstairs the 12” cavity provides about R45 / RSI 8.03. This [pun intended] blows the BC Building Code and its R24 / RSI 13.6 out of the water.

But did I mention that it was the dustiest job in the world?

Next up, we get plastered!

IMG_6485

Karen stapling on floating row cover

IMG_6474

Ready for the big blow

IMG_6477

 

 

IMG_6527

Feeding the machine

IMG_6528

Mid-blow

IMG_6521

IMG_6510

Warm and snuggly

 

 

 

 

Roof Insulation – the crappest job on any build

IMG_6097

Did you say it was 29C today? Lovely, I’ll slip into my swimmers.

By late August 2016, with the daytime highs pushing 30C, the crappest job on the build – insulating the roof – reared its foul head.

Roof insulation is the toque of a house and with the roof generally being the biggest potential source of home heat loss – like a bald man in a Winnipeg winter – it pays to go for a big Canuck toque not a wimpy Antipodean beanie.

The building code minimum for roof insulation here in BC, including up north where they ice fish, is R40 / RSI 7.04 / Metric U 0.14. Good but not amazing. However roof insulation in a cathedral ceiling design isn’t easily upgraded so I opted to go well above the code minimum. The steep bits of the roof are insulated to R58 / RSI 10.21 / Metric U 0.097, the dormer roof is R66 / RSI 11.62 / Metric U 0.086 and the entire midline of the roof at the high point is insulated to between R80 and R120 / RSI 14.09 to 21.13 / Metric U 0.071 to 0.047.

In all we stuffed about 400 batts of Roxul mineral wool insulation into the roof bays and took great pains to fill the gaps between each timber in the trusses. Clad in long sleeves, hats and facemasks it was a like rolling around in stinging nettles for five days and without a doubt it was the hottest, itchiest and generally most rubbish part of the build to date.

After insulating, drawing deep from the well of Karen’s Girl Guide folding skills, we installed a high spec Majpell vapour barrier from Siga in Switzerland, taping and sealing every joint, penetration and individual staple hole, leaving an airtight and vapour proof barrier.

It was a crap job but we somebodies had to do it. And the worst bit was I left my best tape measure somewhere in the insulation.

img_6177.jpgIMG_6096IMG_6107

IMG_6176

Five days with my head up there

IMG_6187

Recyling lumber straps into insulation straps

IMG_6181

Heat shield for the chimney flue

IMG_6188

400 batts later…

IMG_6185

Rolling out the Siga Majpell vapour barrier

IMG_6194IMG_6193

IMG_6196

 

The Earthen Floor Epic, Part I

In a catch-up post from 2016, I promised you’d get to see Mia laying the base layer for our upstairs earthen floor. Well here it is:

 

If you’re wondering what these nut bars are up to laying a mud floor in their new house [the building inspector certainly was], rest assured that we are only at the rough base layer stage right now but here’s what we are hoping for when we get to the final, tinted earthen floor layers later this summer:

http://www.claylin.com/photos/photo-gallery.php

These fine floors are the work of Sukita Reay Crimmel, author of New Society’s Earthen Floors. I had the pleasure of giving her a lift through the mountains and desert of New Mexico in 2015 and bending her ear about earthen floors. She tried to get out of the car but we were driving at 70 miles per hour.

However, I wish I’d have listen more closely to her words about testing as we had a few problems with our initial ground floor sub-floor mix that we later sorted out once I revisited her book. But rather than me blathering on about it in words, you can watch me blather on about it here and how it went oh so wrong and then oh so right.

When we get to the final floors this coming summer, I’ll give you much more detail about how they are laid, the huge benefits, the challenges and how they are finished.

Until then, here are some fun photos of playing in the mud [and really sore knees].

img_5735

Karen whacking straw for the cob

img_5738

Karen, Grandma and Mia mixing cob

img_5747

The mix that later cracked. Too thick, too much clay and not enough sand and fibre

img_5850

Concrete pad and make-up air intake for the wood stove

img_5872

Barley sprouting as the cob dries

img_5879

Prepping height sticks for the main room base layer

img_5883

Living room floor prepped and ready for the cob base layer

img_5885

Bubble material to reduce the probability of cracking around the posts

img_5890

Wood stove air in-take pipe goes under the floor and out through the wall.

img_5894

Mia being swallowed by a massive pile of cob

img_5900

Laying the base layer in the living room

img_5901

You can’t keep John away from this stuff

img_5903

Mia checking the elevation of her section of floor

img_5904

John and Mia in the kitchen

img_5905

The last bits of a seven hour continuous pour of the living room and kitchen cob sub-floor

img_5929

Karen mixing a 20 bucket load of cob with the rototiller

img_5936

Oh my

img_5943

Moving material with the venerable Ford

img_6021

Mia’s addition to her bedroom sub-floor

img_6034

Karen and John laying the sub-floor in our upstairs project room

img_6045

Oh yeah

img_6047

Floor eye’s view

 

 

Rise over Run

img_5088

Sitting on my first set of stairs

As the flowers bloomed in April, I was scratching a bald spot thinking through my first-ever set of stairs.

It’s all about rise and run and the permanence of up and down. So, to ensure the up and down didn’t move, I poured a small concrete pad as a support for a 6X12″ Douglas fir stair landing I dowelled together out of a spare ceiling joist. From this rock-solid base and a fixed first step height from what will be the final main level earthen floor, I had an unchangeable rise to the upstairs floor level.

After that it was relatively easy to calculate the rise and run of the steps and layout and cut doubled-up 2X12” stair stringers that support the sides of the stairs and hold the treads.

These I built out of 3” thick Douglas fir slabs from our mill pile, planed by our two WOOFERs, Ben and Ash, who hail from Devon in SW England. I glued and screwed the beefy treads to the stringers, which in turn are supported by notches I chainsawed into the roundwood posts. The stringers are also lag bolted to the 6X12″ floor joists above, just to be sure. It’s all about 5X stronger than required and I’m very happy about it as I don’t like squeaks. If this explanation made no sense whatsoever then just look at the pictures below.

Ash returned to England after a week but Ben, the son of an old friend from the edge of Dartmoor, stayed on for six weeks and helped me frame out much of the upstairs interior walls. I also gave him a chainsaw lesson and set him loose with our neighbour’s excavator. He moved rocks, bucked up a mountain of firewood and weed whacked in the garden. I think he had a blast.

 

img_4815

Pouring the landing pad

 

img_4817

Nice flat concrete with bolts for the landing

img_4916

The landing sub structure

img_4905

Drilling holes to dowel and bolt the landing slab together

img_4920

Ben lowering the landing

img_4921

Ash steading from above

img_4931

We have the rise and we have the run

img_4912

Planing the stair treads

img_4910

Starting to flatted

img_4914

Treads ready to cut

img_4933

The stringer layout tools

img_4932

The first 2X12″ stringer laid out and cut

img_4935

All four identical stringers

img_4940

Installing the first pair

img_4943

img_4942

Looking level

img_4953

Chainsawed rest for the stringers. I’m pretty happy with that cut done from a ladder

img_5009

Stringers resting on the ledge at the correct angle

img_4962

Gluing and screwing the stringers to double them up

img_4959

One double

img_5008

Lag bolted to the joist and resting on the ledge

img_5013

Risers

img_5082

Completed stair edge from the front entrance

img_5085

Nice Doug fir for the bare feet

img_5086

No more ladders to the upstairs!

img_5159

Framing out the upstairs interior walls

img_5174

Ben bucking up firewood for the winter of 2017-18

img_5180

Ben and John bucking wood from both ends

 

 

Right on Time

img_4220

Mia up for the challenge

In my last blog post, just the other day six months ago, I spilled some virtual ink catching up on the summer and autumn of 2015 in a post that was like an iPhone 6, instantly obsolete and contributing little of value to your life.

A half a year later and I’m a full twelve months behind on updates so I’m going to make a year at the high-performance house building coalface vanish in a [not so] tight 3,000 words spread over a few posts along with a raft of photos [which is all people really want anyway]. I’ll try to be witty but what can you do when so much of it is just about insulation,  and cross-bracing and high spec sealing tape?

So, casting back to 2015, after we got the metal roof on last October I took off to New Mexico for a Natural Building Colloquium, hanging out in the mountains west of the Trinity A-bomb blast site with people who eat plaster for breakfast and build entire houses from clay, straw and sweat.

img_3239

Mum cutting vapour barrier in posh shoes

While I was away my amazing 70-something parents spent three days on their hands and knees on fractured drain rock putting down the impermeable sub-floor vapour barrier in our house and meticulously sealing it around every concrete peer with $80 a roll tape. The barrier is twenty times less permeable than the building code requires and is so tough you can drive construction equipment over it. I can’t overstate how vital this job is to the performance and comfort of our house, how much this sort of job isn’t my cup of tea and how brilliant my parents did with the sealing and detailing. They asked for a ‘substantial and important job’ and so they got it. They still have sore knees.

By the end of the year I’d laid down 6 inches / 15 cm of expanded polystyrene (EPS) foam insulation over the barrier providing thermal resistance of Imperial R24 / RSI 4.23 / U0.23. I have deep ambivalence about using EPS ‘expanded foam’ – the stuff ‘disposable’ [as in last for 1,000 years] coffee cups in the bottom of landfill sites used to be made of. It’s substantially less bad than the rigid pink or blue extruded polystyrene (XPS) foam, which uses much more potent greenhouse gasses during manufacture. But at the end of the day all foam insulation is basically petroleum-based plastic soaked in fire retardant, as are so many commercial building products. This stuff pains me and buying a truck load of the stuff pained me even more.

img_3612

The sub-floor EPS cross to bear.

I contemplated using Rockboard, a firm mineral wool board from Roxul, but it is hard to  find and unaffordable at nearly six times the price of EPS, which also had the advantage of being manufactured locally near Vancouver. A better natural option I learned about too late in the game was hempcrete or ‘hemp lime’ [lime mixed with the inner part of hemp plants], which would have been worth considering for the sub-floor and the walls. It may well appear in the next project and I like it so much that I commissioned this book.

On the upside, despite the billions of foamy balls which plugged and burned out our borrowed vacuum, and the child sacrifice screeching sound when I cut it that had Karen in hysterics, substantial EPS sub-floor insulation over an impermeable barrier results in a bone-dry floor with a very slow rate of heat loss to the earth. This is the absolute inverse of the half-subterranean, damp, stone floor-over-bare earth deep freeze that Mia lived in as a baby in Crystal Palace, South London. When we moved from that flat, the carpet under the bed was covered in mould and we had to bin the almost new mattress. Of course that place was a virtual Atacama Desert compared to our Streatham flat. It’s so often these cold, damp blanket recollections of my UK housing experiences that drive my quest for very warm and very dry in our house.

Bizarrely, like Hyde, after I was done the sub-floor insulation I sort of wished I’d used even more EPS and laid down 12 inches / 30 cm of EPS to double the floor insulation, as if I lived in Flin Flon rather than the [imaginary] Canadian Riviera. When is enough, enough?

On top of the EPS, which has an impressive compression rating of about 2300 lbs/sf / 11,300 kg/m2, we framed the internal ground floor walls of the double wall system making 16-inch / 40 cm thick exterior walls downstairs and 12-inch / 30 cm thick walls upstairs.  During this time, my sister dropped in for a few days from Calgary and for an early 50th birthday present I showed her how to use the mitre saw without losing fingers. She chopped studs while I nailed and we managed to frame out the double walls of both the upstairs gable ends over a weekend.

This whole internal double wall framing business involved nearly six weeks of building custom top plates and air baffles and extensive air sealing detailing using roll after roll of [really, really, really expensive] Siga Wigluv sealing tape. The temptation to get lazy was always and ever present and the only antidote was lunch, coffee and judicious eyedroppers of my not-quite-buried childhood perfectionism.

As the foolish Europeans who arrived to colonized this place fewer than two centuries ago never knew, the BC coast is historically a brick-shitting deadly seismic zone. To mitigate [some of] the risk posed by a megathrust earthquake, which builds with every passing hour that the Juan de Fuca plate sticks to the North America plate in the Cascadia subduction zone, my engineer specified heaps and heaps of cross-bracing. So, I spent weeks and weeks cutting and nailing 2X4 ‘X’s into the double walls to a prescribed pattern until the entire house was thoroughly cross-braced.

There are a numerous seismic features in the house. The concrete foundation pinned into bedrock and large, frequently spaced anchor bolts and heavy steel post tie-downs should keep the house from doing the table cloth and dinner plates routine in a big shaker and sliding off the foundation. Hurricane ties between the roof and the walls, galvanized strapping between the gables and the rim joists and many, many dozens of foot long engineered GRK structural screws and heavy bolts should keep the layers of the house from flying apart. Lastly, the cross-bracing should in theory keep the whole thing from buckling. At least that’s what the calcs say, though the upward seismic limit isn’t known. With massive earthquakes it’s all about distance, depth and duration and unknown, unknowns.

About the same time we added the cross-bracing, in went the sub-floor plumbing for the toilet, bath, sinks and water delivery lines. Then we wheel-barrowed in and compacted 11 tonnes of road base [gravel, sand and clay] as a solid base for the eventual earthen floor. Much more on this later when you get to watch a video of Mia laying floor.

For now, here’s some more pics of insulation and cross-bracing and sealing tape.

See, now that contributed value to your life.

 

img_3238

Fiddling with the vapour barrier

img_3322

Pleased as punch

img_3329

Completion photo

img_3354

Pier detailing

img_3364

Water line and power line penetrations

img_3611

My ‘just in case’ radon gas mitigation pipe

img_3616

img_3713

Sub-floor waterlines for the loo and the toilet flange

img_3662

Laying out the downstairs loo walls

img_3788

img_3789

More subfloor plumbing

img_3799

Sealing the sub-floor vapour barrier to the exterior sill plate

img_3801

And nailing it for life

img_3985

Laying out the floor plates for internal walls

img_4084

X bracing at a window

img_4085

And more

img_4095

And more

img_4592

Shear wall X bracing

img_4593

and more

img_4679

Custom double wall top plates and Siga tape air sealing

img_4683

Gable end double wall

img_4694

More air sealing

img_4696

Collar ties I added to create the plane of the upstairs ceiling, and the future chimney location

img_4788

Dormer air sealing baffles

img_4796

Upstairs double wall with X bracing on the outside

img_4751

Pat chopping studs like a high schooler

img_4760

One sip and she’s blurry

img_4236

Karen moving road base

img_4208

And more

img_4227

And much, much more

img_4247

Mia spreading the road base

img_4256

Rob on the plate compactor

img_4767

And look what happened in the garden. The elderberry tree was blooming

img_4768

And some early flowers

 

Cirque du soleil Part Deux

IMG_3140

I’m back on that treadmill of pounding nails and publishing books by day and researching hot topics like the counter intuitive best way to air seal a window according to NRCan by night. [Really, no caulking under the window flange, for real, I’m not making this up, it’s all about the Delta P.]

While I luxuriating in my evening hours borrowed from the future, I realize that my blog is still living in the summer of 2015, while my house build lives in the winter of 2016 and my publishing brain lives in the spring of 2017.

So rather than subject you to eight or nine scintillating posts about humping 112 sheets of plywood up on the roof, the depths of my neck tan, the moments of despair as the rain broke through the tarps and saturated our T&G ceiling, or the mad dash to get the metal roof on before the heavens unleashed the autumn gales if it wasn’t for that bleeding Rothenburg 49 degree pitch, I’m going to give you the back-of-a-beer-mat version with a truckload of photos. When you emerge on the other side it will be the spring of 2016  and we’ll all be in a better place.

Then we can get on with talking about thermal mass and swoon to the viscidity of Swiss Siga sealing tapes. Oh, yeah. Be still my beating heart.

Here we go.

 

IMG_2666

 

IMG_2400

IMG_2824

The task list [took twice as long)

IMG_2845

Nice outriggers

IMG_2868

Strapped so the engineer can sleep at night

IMG_2883

IMG_2904

Chris Sauer volunteers to be monkey man

IMG_2924

Half of the sheathing on. Cursed dormers still to come.

IMG_2976

Clamps and string. That’s how you build it.

IMG_3022

IMG_3023

11mm of pain

IMG_3026

Definitely water

IMG_3037

Framing out a dormer wall

IMG_3046

Rolling the barge boards

IMG_3050

IMG_3054

Two days to hang those before the roofers arrive

IMG_3058

Dormer meets the roof peak

IMG_3077

All 112 sheets of plywood on the roof

IMG_3082

Tammy, Karen’s mum, lends a much needed hand

IMG_3092

Dad, remember this from the ’80s? Guess where I learned that trick?

IMG_3120

Almost there

IMG_3122IMG_3124

IMG_3130

Karen thought today was going to be about gardening

IMG_3140IMG_3141

IMG_3143

Still together after all those fascia boards.

IMG_3144

On the so-called ‘chicken strips’

IMG_3191

Get it on lads

IMG_3193

Metal for the ages

IMG_3195IMG_3196IMG_3334IMG_3336