Article
May 26, 2005
Condo Concepts - May 2005, Issue 35
PART 11: Building A Solid Foundation
Once the earth is excavated from the building site, crib walls are constructed to keep the compacted fill in place for the next stage of development: concrete and framing.
A concrete footing is a foundation for a foundation. It is the base on which the wall fits on. Onsite there will be a foreman, two placers, a pump operator, and three drivers.
Randy Caravaggio, a shareholder of Four Star Concrete explains, “The head placer will walk along the ground and hold the hose. The concrete is distributed into the footing from the concrete pump truck. The concrete truck empties into a hopper into the back of the pump then is pushed through a bunch of pipe. The end of the hose is placed inside the footing. The placer walks along as the operator goes with him and moves the boom with him as he walks. The second placer follows behind him with the trowel, floats the footing out, and tries to get it as even as possible.”
It may seem like a simple explanation, but this can be one of the more dangerous jobs on a construction site. “When the walls are being poured, these guys are holding a hose and walking along an eight-inch wide top of a wall. When it’s raining, it can be slippery. They have to pour the concrete inside the wall a certain way or you’ll get what you call honeycombing – when the forms come off the walls.
“These guys can’t tie down because they’re constantly moving. You need a good pump operator that won’t jerk the boom. If he does jerk the boom, he risks knocking that placer off the wall. Most of the time, if a placer loses his balance, he holds onto the hose and pulls himself back up with it.”
There are about seven standard concrete mixes and each jobsite requires a different mix. For condominiums, it’s usually higher strength powder that doesn’t react to certain soil conditions. Certain soil conditions will break down concrete mix.
The concrete must retain a definite wetness. You can’t tell by looking at it what type of concrete it is, so engineers test it over several days before the contractor gets the go-ahead.
Caravaggio says winter weather can impact pouring. “We usually like to set a minimum coldness like about minus 18. There’s a risk of the wall freezing and the machinery not working that well. You don’t want to pour 50 metres into a wall, have it freeze, tear it down, and start all over.”
Next is framing. “My job is to take a concrete foundation and put the wood frame on it,” says Dave Marcine of Explore Contracting Inc. “We’re pretty much left on our own because we take up so much space.”
For two-storey units with garage, the framers start putting in the garage door walls, the fire separation walls between the units, the basement level, and other baring walls before the floor. Then walls go up onto the floor.
After the floor, it’s walls again, then another floor, and walls again, then the roof.
The number of framers onsite will depend on the size of the project. “What works well for us is a man per unit plus one,” reports Marcine. “On a five-plex, you’d have six guys. On an eight-plex, you’d have nine.
“We do work year-round. What slows us down the most is snow. Twenty below isn’t bad. Once your air compressors stop working – the power tools are fine – the cold will affect your air tools. Once you lose your air tools, production really drops.”
To Marcine, the framers’ job is sorely underestimated. “I had a conversation with someone the other day who said there was nothing to framing. People think anyone can frame. There’s a lot to it, especially on a bigger project. There’s a lot you have to know – custom things when you’re not doing the same thing over and over.
“Everyone else’s work hinges on the framing. The concrete trades only have the framer to worry about. For the framer, the finisher’s work hinges on it, the drywallers’, the roofers’, the plumbers’ work. Probably the only one that doesn’t is the electricians’. The siders’ work hinges on it. There are so many other trades that the framer has to keep in mind and how their work affects the other trades. There’s a lot expected of us.”
Everyone’s job on a project is important. But without a well-laid foundation and skilled framing contractors, the rest of the jobs are just that much harder.