What are the risks of DIY concrete work in NB?

DIY concrete in New Brunswick carries real risks that are specific to our climate and building code requirements -- and mistakes in concrete work are permanent, not easily undone.

The most costly DIY mistake NB homeowners make is using the wrong concrete mix for exterior work. Standard concrete without air entrainment will begin scaling and spalling within 3-5 years under New Brunswick's 150+ annual freeze-thaw cycles. Once surface deterioration begins, it accelerates. A driveway or patio that looks fine in year three can be badly pitted and deteriorating by year five. Always specify air-entrained concrete (4-7% air content, 25-32 MPa) for any outdoor flatwork -- driveway, patio, steps, or walkway.

Insufficient frost depth on footings is a structural risk. In New Brunswick, all structural footings must reach a minimum of 4 feet below grade in the south and up to 5 feet in the north. A sonotube footing that stops at 2 or 3 feet will heave every winter, gradually pushing your deck, fence post, or structure out of alignment. After a few years, the cumulative movement can make repairs more expensive than starting from scratch. This is one mistake that cannot be patched.

Timing and finishing errors are hard to recover from. Ready-mix concrete begins setting immediately upon delivery. A first-time DIYer who misjudges the timing, runs short of help, or struggles with screeding and floating may end up with a surface that is uneven, rough, or marked with footprints and tool marks -- permanently. Unlike paint or flooring, you cannot simply redo a concrete slab that has already set. Similarly, concrete poured when overnight temperatures will drop below 0 degrees Celsius without cold weather protection will suffer permanent strength loss of 20-40%.

Reinforcement errors affect long-term performance. Wire mesh or rebar placed on the ground instead of elevated to mid-slab height on chairs ends up at the bottom of the slab, where it does nothing structurally. A slab without reinforcement, or with incorrectly placed reinforcement, will crack and pieces will separate over time under NB frost heave forces.

There are also safety risks specific to concrete work: freshly mixed concrete is highly alkaline and causes serious chemical burns on unprotected skin. Excavating for deep footings in NB's variable soils creates trench collapse risk. And handling ready-mix trucks on a residential driveway without proper preparation can result in property damage if the truck sinks into soft ground.

The practical guideline: small flatwork under 1 cubic yard (patios, shed pads, sonotubes, repairs) is reasonable DIY territory with proper mix specification and preparation. Driveways, foundations, structural footings deeper than 4 feet, retaining walls over 2 feet, and any pour over 2 cubic yards should involve a professional. New Brunswick Concrete can match you with a local contractor for any project where the risk of DIY is too high.