Greg Baker has seen the future of concrete block and it’s light — half the weight with double the bang for the buck over traditional block.
The Kitchener, Ont.-area former renovation contractor turned entrepreneur has been steadily building a new business plan over the last two years around a cellular concrete mix to make dry-stack concrete blocks and their Redi Mix product for floors and roofs.
His company, Litebuilt Concrete Canada, has licensed an Australian formula and manufacturing system and has been working with the National Research Council (NRC) to prove the credibility of the product.
The advantages, aside from the weight, are that it is a cost-efficient building material that combines both superior sound and thermal insulating properties along with a one-hour per inch fire rating.
“The acoustical property on the block alone is a STC 43, whereas code is 50,” says Baker. “With a two by four stud wall and half-inch drywall the STC is 52. The same block has a five-hour fire rating. It’s really two products in one when you have a sound transmission standard and fire, providing two codes in one wall you have to meet and that’s a cost saving for contractors.”
Depending on the concrete mix density, the R-value per inch ranges from 2.54 at 300 kilograms per cubic metre (kg/m3) to .46 at 1,600 kg/m3. The compressive strength gives a 28-day megapascal (MPa) of .07 at 300 kg/m3 with a sand to cement ratio of 0:1 all the way to an 28-day MPa of 18 at 1,600 kg/m3 at a ratio of 3:1.
Litebuilt Concrete Canada uses the patented system to create concrete that is about half the weight of traditional concrete yet with all the strength required to meet Ontario’s building codes.
The mix uses a foaming agent that Baker describes as being like “shaving cream” to create air pockets in the concrete. The end result, he says, is like “a chocolate Aero bar, all full of bubbles.”
Cellular concrete is common around the world and Litebuilt alone is in 65 countries. It’s favoured in hot climates because of its thermal properties but it’s also popular in cold climates. In Canada, however, cellular has mostly been used in road beds or on bridge abutments though there is a large manufacturer in Calgary.
“It’s a dry stacking block which is about twice the size of a traditional block at 10 high by 20 long, only five inches wide, yet the same weight,” he says. “So the blocks go up much faster and lock together and of course time is money. It’s essentially Lego for concrete blocks.”
The mix is made at Litebuilt’s manufacturing plant which employs seven people and can churn out 1,200 of the double size blocks daily. Baker is looking to build and deliver turn-key plants across Canada with manufacturing plants opening in Alberta and Quebec this summer, as the concept of cellular concrete builds traction.
“If we need to ramp up here we can just add another unit,” he says.
Bringing innovative products to the construction industry is always difficult since traditional materials are a known factor and many owners, architects, engineers and contractors are risk averse and reluctant to be the first to try a new concept.
However, Baker says, recent changes to the Ontario building code to permit six-storey wood buildings has opened a niche.
“They still have to have fire resistant stairwells and elevator shafts and this product is perfect for that,” he says. “So we’re also working with the Wood Council of Canada.”
He came across the product in 2011 while working in Haiti on restoration following the 2010 earthquake. Inspired, he went to Australia to meet with the manufacturers and came back with the licensing for Canada.
“Since then I’ve been jumping through hoops to get evaluations and the NRC’s Canadian Construction Materials Centre codes for the product,” he says noting the last of the testing was expected to be wrapped by this summer.
“I can’t say enough about the NRC and how they’ve stepped up on this,” he says. “They’ve been fantastic to work with.”
The Redi Mix product is designed as an acoustical barrier and because of its light weight can be poured up to an inch- and-a-half on floors and four inches thick on existing wood joist-supported floors.
“In townhouses and other multi-storeys you want to kill the sound of people walking on the floors above a unit,” he says. “We lay down sound mat material between the wood and the concrete to separate them and then pour.”
The mat can be a premium acoustical material or a simple waterproof material to contain the water in the concrete and prevent sound transmission. The more expensive mat adds acoustical dampening properties. No other structural support is needed.
With the trend to green roofs, he says, cellular concrete also provides a structurally sound solution. This particular design mix is water resistant and will actually float.
“You don’t need to add a lot of support for the roof, you can pour it right on top and then add dirt and grow grass and plants,” he says.
Litebuilt was recently recognized by Enerquality and over 100 of the top builders voted Liteblok Innovation of the Year 2016 in February.
“This is something we are very proud of and shows that we are on the right track as building codes become more complicated,” said Baker.