Studio Construction: Porch Floor

I was quietly working away at my desk when I heard a large truck arrive.

It delivered a load of concrete onto the porch area.

Citywide Concrete Company got the job to make the porch floor.

Lines were cut in the smooth, wet concrete to absorb the stress that otherwise would cause cracks.

The Finish: After waiting until the applied retardant had set to just the right amount the surface of the concrete was gently washed...

...to expose the top layer of aggregate.

Once the concrete has dried and cured over a few days Ron will brush off the white residue then apply a sealer to stop it absorbing whatever I might spill on it.

And there it is - the porch floor. It won't require any maintenance other than sweeping and a spring wash. It won't rot or decay as a wooden deck would. It is sloped a few degrees away from the wall so spilt water and driving winter rains will drain away to the garden bed that will be built in front of it. 

Studio Construction: Porch Floor Preparation

Remember I posted about finding these bent rebar rods Dave had made. 

Now I know what they are for.

He drilled holes in the foundation wall then inserted the rods where the porch floor will be.

 

A rental delivery dropped of a gas powered hand operated compactor.

Dave compacted the backfill where the porch floor will be constructed.

Next a small, rubber-tracked digger was dropped off.

It built up the soil for the porch floor and did a bit of landscape earth shaping on the south side of the studio area.

Studio Construction: Services and Backfilling

Oohh! A new van. The plumber.

The house water main now has a new line going off it - to the studio.

The white line takes water to the studio.

The electrician has laid the first of the power and services conduit coming out of the studio crawl space. He puts zip lock bags over the ends to keep the soil out.

This is the water pipe coming out of the building from the wash tubs and feeds into the nearby septic tank.

Once all of the crews had gone for the day, Ron and I backfilled the trenches near the studio building. We wanted to cover the exposed tree roots as soon as possible before they dried out.

Studio Construction: Work Continues Inside and Outside

After the first day of securing the drywall panels in place. The ceiling is done.

Ron and Dave check the work.

Dave has been lining the crawlspace with plywood. His assistant, Paul, sweeps up after a day's work.

We are really pleased with the way this area is looking.

Dave has also put in place the formwork for the porch floor.

A small load of gravel was dropped off and leveled out. Dave attached rebar rods to the wall and extended them out into the floor area. He added a wire mesh and a rebar grid - all so the concrete would be well supported.

The taped brown paper is to protect the wall from splashes when the concrete is poured.

Studio Construction: Work Inside and Outside

Ron and I have the job of digging the trench to hold conduit for services from the house to the studio.

Unfortunately, the trench passes between a large Douglas-fir tree and the house. It is my job to dig around the trees roots while making the trench. The roots I come across are the uphill ones which are the most important for holding the tree upright on the slope. I take care not to damage them while using small tools and my hands to clear away the soil.

Meanwhile, Ron uses big tools to dig out the bulk of the trench.

The work on cladding the building continues and we watch as it seems to be visually disappearing into the forest.

The building code requires the 2 walls near the house to be fireproof, which was one of the reasons we went with metal cladding.

The inside is ready for the next stage. A delivery truck dropped off sheets of drywall....

...tape and mud.

We had considered lining the inside with other materials but decided the fireproof feature of drywall made it the lining of choice.

Studio Construction: Lots of Action on the Job Site

Our back yard is a very busy place. A small digger is moving backfill soil around according to the landscape plan. The sheet metal workers are working at their benches. The insulation team has arrived with 2 truckloads of materials. Ron and lead carpenter Dave are having a meeting.

Alpine Insulation has the contract to insulate the building. 

We considered spray foam insulation which is considered the best. After Ron did all of the calculations he concluded we couldn't justify the foam. Here on the island we have mild winters and the small savings in the heating bill would not pay for the extra cost of spray foam over the life of the building. The eight-inch thick walls and high-efficiency construction method have already made the building thermally more efficient than conventional buildings. The design of a high-performance building envelope does more than anything else, more than adding any 'green bling' items, to reduce construction and operating costs over the life of the building.

R28 fibreglass insulation batts are pushed into the spaces between the roof rafters.

Batts are pushed into the spaces between the framing. The experienced installers cut the batts to fill the spaces evenly while pushing the batts in only so far to leave an air space next to the wall. All ductwork is surrounded by batts.

The walls are sealed with a heavy gauge plastic, caulking and black sealer along all edges. This air barrier must be in contact with the insulation with no insulation exposed. Sealing prevents convection currents building up fanning heat away from where it is needed.

The plastic is also a vapour barrier to control or stop condensation. High humidity moves to areas of low humidity and cooler areas such as the outer wall. The batts and the rigid foam insulation board over the doorways and window openings slows down the warming of the walls and increases the total insulation value of the walls. Insulation also reduces thermal bridging across materials such as wood which is a good conductor of heat.

The crawlspace walls and ceiling are insulated with batts and sealed. The floor pad had rigid insulation foam sheets and a waterproof barrier in place before the concrete was poured. The crawlspace needs to be sealed and unventilated to stop the flow of moisture and air into the space and up into the studio space. Buildings in the north 'dry' out so the walls need to let water go out which means the vapour barrier needs to be on the inside of the wall assembly.

While all of this activity is going on outside I am sitting inside calming stitching. Well, trying to. I must admit I do get distracted when something new arrives on the site.

Studio Construction: Cladding Choice

The east side now has 3 sheets of metal cladding.

The biggest negative of cladding a building in steel is it has a poor thermal value when compared with almost any other material. But the positives of metal being our cladding of choice more than cancel out the one negative, particularly when it is being applied to a building envelope with high thermal efficiency.

The sheet metal team layout the material according to size and shape.

One of the big positives of sheet metal is its long term durability. It resists weather and pests. By choosing a corrugation and placing it vertically driving rain is channelled down off the walls into the perimeter drains straight away without any detours or pooling. Wayward and pooling water cause buildings to decay rapidly here in the forest. The corrugation channels also allow air movement between the sheet and the sealed building envelope. The movement of air is critical for reducing the buildup of humidity and its related problems.

Dave and Michael take measurements at the wall then come back to their workbenches to cut and shape the steel.

We went with wood framing because it is  a locally grown and harvested material, but the construction method ensured all of the wood is enclosed within the building envelope, except for the cedar that I will explain later. Here in the rainforest exposed wood decays rapidly. It is how the forest ecosystem works. The metal cladding is the first protection layer of the wooden framework.

Another big plus with metal cladding is the finishing paint is baked on in the factory. The finish is without flaws because it was applied in controlled conditions resulting no weak areas susceptible to decay. Factory paint application is done at high speed and with little waste as opposed to painting on site. Another advantage is it eliminates the need to take finishing materials to an environmentally sensitive site with the added task of disposing of the leftover paint and cleaners. It is challenging to do an outside, high-quality paint job in a timely manner where rain is a frequent occurrence.

Cladding progress on the east wall.

While factory painted metal sheets won't break down when exposed to the elements, we also chose to go with a heavier gauge steel for added durability. Metal sheet thickness is measured by the number of sheets that make up a specified weight, giving a gauge number. We went to 26 gauge rather than the 24 or 29 gauge. This added strength fits our design requirement that the building and material finishes have a life expectancy of 25 to 30 years before needing maintenance or replacement. All of the trim, soffit and guttering will be made out of metal and will have a similar life expectancy. The building is located under tall trees and will likely be hit by the natural process of falling branches known as snags. The thicker gauge sheets will resist possible denting better than lighter gauge sheets.

Progress on the north wall is much faster with fewer wall penetrations to work around.

Another plus for metal cladding is that it is infinitely recyclable. It requires a lot less energy to repurpose the metal than to make new metal. The cladding team takes a lot of care to cut efficiently resulting in minimal waste on site. The waste that is created will be taken away to Wilsons Metal Exchange for meltdown and recycling.

Panels are going up on the south wall, working from the bottom up.

Another plus for the metal is it is fire resistant. The building code requires the 2 walls closest to the house be clad in a fire resistant material so we could have gone with another material for the other 2 walls but with the building being located in under trees there is the risk of a fire source on 3 sides. Cladding all walls in steel is the safe option.

These are the reasons why steel ended up being the cladding of choice.

There were design reasons for the choice of metal too (in another post).

Studio Construction: Skilled and Unskilled Labour

Ron and I are at work, in the unskilled category.

I am working with small tools and hands to carefully clear around tree roots that go across the service trench.

Ron uses his strength to wrestle with large rocks he comes across in the trench.

Here is a video of Alex doing skilled work, cutting and shaping metal to clad the studio. He is an architectural sheet metal worker. He works with electrical power tools and a variety of hand tools. He carries the hand tools with him in a tool belt around his waist.

Alex instals a sticky foam strip with the same shape as the metal panel. It is stuck in behind the bottom of the panel. Its purpose is to stop the bug world from inhabiting the spaces between the metal and the Tyvek. No insect condominiums available here.

Then the panel is fixed in place with screws painted to match the colour of the metal sheet.

The headless person is sheet metal worker Michael.

Meanwhile, back in the trenches... I had covered the exposed roots with wet coffee sacks to keep them from drying out. But the coffee sacks must be treated with something because they don't hold any water.

Plan B - I wrapped each root with a strip of wet wool blanket then covered them all with the coffee sacks. This plan appears to be working better.

Back to the studio. The large east wall has its first panel of corrugated sheet metal cut, shaped and attached.  It looks fabulous.