Wednesday, October 27, 2010
Hoses, vibrators and concrete
Oprah and Barbara Walters know first hand that there is nothing better than a guest with a good story. Just in our case it happens to be someone a little less famous than Bill Clinton or Lady Gaga. Welcome Roger Purdy, the steadfast, unwaveringly father of Brendon Purdy. A chemical engineer by training, Roger has been watching the construction like a Brazilian soccer fan at a World Cup Final. Since I've been at work and Brendon's been in Ottawa, he also happens to be the only person that has been watching. To give you the play by play of the most recent adventures of hoses, vibrators and concrete I'm passing it over to Roger Purdy.
Roger Purdy speaks: Today was the day that the foundation got poured. One monster pumper truck and a cement truck for one little house.
THE PLAN: With cement in pumper truck, a hose would extend to the framed foundation and pour wet cement into the mold.
WHAT REALLY HAPPENED: The pumper truck was so large that the outriggers (stabilizers) on its side could not be extended in the laneway to support the weight of the hose. Under the weight of a 100lb hose and no stabilizers the truck could have tipped over. This was definitely not an option so the men had to rejig their original plan and use the hose on the basement level instead. This was a major change - one worker had to be in the basement all the time supporting the weight of the hose and moving 2x4’s around to prevent it from falling down.
Suddenly, the pour began. The first blast of concrete out of the hose splattered water and dirt all over the place – I thought that a major clean up would be required, but this was the initial priming of the system, not the actual pour.
The pour began with a 4 inch (10 cm) ribbon of concrete coming out and jetting about 2 meters from the end of the hose - thankfully, most of the concrete ended up in the forms, but there was a considerable amount of spillage too. The fellow had a big job. Not only did he have to hold the weight of the hose, balance on top of the forms, manage the changing pressure of the concrete as it came out and make sure that the everything was pointed in the right direction, all while watching that he was filling the form correctly. The man on the vibrator had to balance on the forms, pull the vibrator around with him, untangle the electric cord from the supports and forms, make sure all the concrete was settling OK, and help the man pouring and the man lifting the hose. And then of course there was the third man, (the one in the basement) making sure that the hose moved where needed. The fourth man on the pumper truck was controlling the flow of concrete, yelling instructions, making sure the pumper was full of concrete (or maybe that was the fifth man from the cement truck.
All I had to do was take pictures and drink tea. Good division of labour. Overall, considering the challenge, it was very efficiently done.
Easy and elegant it was not. That said, despite the challenges it was well educated...and highly entertaining.