Calgary’s extreme weather is unique and very hard on concrete. Older construction techniques, settling of poorly compacted earth, and low-quality workmanship on newer driveways are the leading causes of failure.
Residential concrete in Calgary that is older than circa 1990 is often void of rebar. Sometimes we find some 6"o.c. wire mesh but 50/50. The problem is concrete slabs will almost always have a crack in them during their lifecycle. When rebar is absent that crack is able to turn to full separations and failures. A lack of rebar also means that even if your pad or sidewalk is structurally sound it may slope negatively towards your property as there is no rebar drilled and attached to your house foundation.
Poorly compacted earth near attached garages are the #1 contributor to failed slabs. Backfill from the house foundation pour settles over time and if the driveway doesn’t have rebar and/or cantilever strength then failure of the top panels is imminent.
Newer driveways that aren’t finished properly tend to delaminate (spalling) after only a short time. Factors that lead to a poor quality slab include, but are not limited to:
- High Water/Cement ratio. Subcontractors and inexperienced finishers will add too much water to the mix upon arrival at site to make their jobs easier. This leads to plastic shrinkage cracking and overall strength loss.
- Inexperienced finishing procedures. Overworking concrete that has visible surface bleed water will change the chemical makeup of the slab surface, reducing strength. Or the slab will be getting too hard for the experience of the crew and they will use water on it to ‘save’ the job, same result.
- Lack of/low air entrainment. Air entrainment is the intentional creation of tiny air bubbles in concrete. It’s done by adding a surfactant admixture to the ready-mix at the batch plant. This allows freezing moisture present in the slab a place to expand. Incorrect mix design, zero testing, over mixing, and poor attention to finishing all contribute to an incorrect air entrainment percentage (ideal ~5%).
- Curing concrete is overlooked by many companies and homeowners. Concrete must be kept moist or covered for the first week to ensure your investment stands the test of time.
When it is time to call a professional, head to our website to learn more about how we provide the best concrete driveway replacements in Calgary.
Removal is quick and precise. Attention to safety and respect for your property is what we focus on during removal day.
Thick gravel substrates, proper compaction, and chaired rebar grids all need to be installed prior to ordering concrete.
Concrete is an unregulated industry in Calgary. You wouldn’t let an electrician into your home that wasn’t a Journeyman…so why would you hire a concrete contractor on Kijiji? Do your research and you should be able to replace your driveway in Calgary and enjoy it for decades to come.