Stirling Roofscape

The guys are starting to deck the third floor. I wasn't comfortable to climb up there to sketch so contented myself with the view form the second floor.  This will be the view from the rear bedroom. The Hintonburg roofscape is charming and the Peace tower is quite prominent. We realized recently that the views from the roof deck will include not only Parliament Hill, but likely the Gatineau Hills as well.  Spectacular.

Marty and Mike, the two lead carpenters, had hung the trusses for the third floor and rear deck and had just discovered a slight discrepancy in the side wall lengths - like an inch over 40 feet.  True to form the conversation was, "find out where the mistake is and we'll fix it".  Cabinet making 30 feet off the ground.

Hanging Steel

These buildings are complex.  They have a hybrid structure of reinforced concrete, steel beams and posts and wood framing.  The steel beams are incredibly heavy so Bramel had to bring in a crane.  They were placed on temporary wood cradles and Fluxworx welded them together.  The carpenters are looking forward to putting up permanent walls after all this temporary false work, forming and bracing.

I stood well back. I don't like being under heavy things swinging through the sky.

Pouring the Walls

Last week the foundations  and ground level of the fist two units were poured at the Parkdale site.  The forms were more than 10 feet tall so a lot of care was taken to reinforce and brace the walls before placing the concrete. The greatest fear with this operation is a blow out due to the weight of the wet concrete.  A 90 degree pipe was put on the pumper hose to slow the rate of  concrete being delivered, so that there would not be a sudden load which might break a weak point in the formwork.  The walls were poured to the 5 foot mark and allowed to set up before topping up the remainder. Accelerator in the concrete mix allowed the first lift to stiffen in just an hour, so that the remainder would not put undue pressure on the formwork.

ICF Foundation Walls

The last couple of weeks have been really really cold - like -30 C in the morning and -20 C through the day so we lost several days to weather.  Luckily the cold spell broke and at a balmy -15C the guys have been able to get back at it.

Bramel is  using a product called Polycrete, which has steel bands embedded in the rigid insulation with metal ties between the panels.  The corners are plumbed and reinforced with steel angles for the pour.  Once the concrete is set, the corners come off, but the insulation remains. The other benefit is that the insulation will slow the cooling of the concrete and give us good strength dispute the cold temperatures.  Polycrete have been very supportive and have sent a technical rep. to show the crew the system and will review the bracing before the concrete is placed.

It took some time just to open the large bundles and sort the various heights and wall width panels, making it hard to move around this compact site, but as the forms are assembled there is more space.

Stirling Ave Footings

When I moved to Ottawa in the early 80's construction went on hold until March or April.  Between the milder winters and construction techniques intermittent work right through the winter has become the standard practice.

Last week we had minus 20 C for several days and about 60 cm of snow.  I was thinking, maybe we should hold off till spring.  Brad knew better.  The weather broke this week.  It has been just at the freezing point for several days allowing the guys to form the footings on clean bedrock.  They drilled lag bolts into the rock to brace the forms which are level on top, but slope, or step,with the slope of the slab rock.  Today the forms were about done and the guys were starting to assemble the steel reinforcing bar grids and dowels that will go into the footings.

Looks like they are in good shape for placing concrete on Friday, which is forecast to be mild so we won't have to pay the 10% premium for cold weather admixture to the concrete mix.

Big Day on a Small Site

A surveyor will verify the grades tomorrow, but it seems the breaking-out of rock is complete.  John McRae has been using a large shovel to load the fractured limestone into trucks for two days to empty nearly the whole site to a depth of 1.5 -1.8 m.

The form materials were being delivered ready for forming of the foundation walls directly on the rock. Large packages of the styrofoam modules that will be assembled as insulated concrete forms were lowered into the hole with a special boom truck.  Even on a small project like this as much as possible is done by machine. The next step is is assembly of the forms which will likely take about a week, depending on the weather.

Chipping Out

We started removing rock on the Stirling Avenue project Wednesday. It is limestone and breaks fairly easily where it is weathered near the surface, but is much harder below about  60 cm. down.  John McRae is the excavation contractor and he has to really 'put his sholder into it' using the wieght of the machine to force the bit down into the rock which lifts the front of the tracks right off the surface. He handles that machine like a surgical tool.  I think if we taped a pen to the end of the hoe-ram he could sign his name.

We're not going down to a full basement, just for frost cover so we should be ready for forming foundations next week.