What is the structural difference between a bench footing and a full underpin and which is more appropriate for a Moncton bungalow?

A bench footing adds a new concrete ledge inside your existing foundation to support a thickened floor slab, while full underpinning excavates beneath the existing footing in staged sections to physically lower the foundation and gain true ceiling height. The structural difference is significant — bench footing is a floor-level solution, underpinning is a foundation-level solution.

How Each Method Works

Bench footing involves pouring a new concrete "bench" or shelf against the interior perimeter of your existing foundation walls. The bench sits on the existing footing and supports a new thickened slab poured at a lower elevation in the centre of the basement. The existing foundation footings are never touched or undermined. The tradeoff is that the bench itself consumes floor space — typically 12 to 24 inches along every wall — and you only gain usable height in the middle of the room, not at the perimeter.

Full underpinning is a completely different structural operation. Contractors excavate beneath the existing footing in alternating sections (typically 3-foot-wide "pins"), pour new concrete to extend the footing deeper, cure it, then move to the next section. This process transfers the structural load of your home progressively to the new, deeper footing. Once complete, the slab is poured at the new lower elevation across the full footprint. You gain full ceiling height wall-to-wall, with no bench eating into your floor plan.

Which Is Right for a Moncton Bungalow

For most Moncton bungalows, bench footing is the more practical and cost-appropriate choice — but the answer depends heavily on your existing ceiling height and your goals.

Moncton sits on sandy and silty soils with reasonably good natural drainage compared to Saint John's heavy clay, which makes excavation somewhat more manageable. However, the staged underpinning process is still a major structural undertaking requiring engineered drawings, a structural permit, and a highly experienced contractor regardless of soil type. Full underpinning in Moncton typically runs $30,000–$80,000+ depending on footprint size, soil conditions, and access. Bench footing runs considerably less — roughly $15,000–$35,000 for a typical bungalow footprint — because it avoids the risk and complexity of working beneath an active footing.

The critical question is your existing ceiling height. NB Building Code requires a minimum of 6 feet 5 inches (1,950mm) for habitable basement space. If your Moncton bungalow already has 7 feet of headroom, bench footing after a new slab pour may get you to a comfortable finished height. If you're starting at 6 feet or less, bench footing may not get you to code minimum in the centre of the room, and full underpinning becomes the only viable path to a legal finished basement.

Practical Tips Before Deciding

Measure your existing height from the top of the concrete slab to the underside of the floor joists — not from a dirt floor if one exists. Account for the thickness of your finished floor assembly (Dricore subfloor plus LVP adds roughly 1.5 to 2 inches). If you're borderline on height, a bench footing may solve your problem at a fraction of the cost of underpinning.

Either method requires a structural permit and engineered drawings in Moncton — this is non-negotiable. The City of Moncton's building inspection department processes permits in roughly 1 to 3 weeks for residential projects. No reputable contractor should touch underpinning or bench footing work without pulling the proper permits.

Both methods also require waterproofing to be addressed first or concurrently. Moncton's sandy soils drain reasonably well, but spring thaw hydrostatic pressure is still a real concern — installing an interior drainage channel and sump pump as part of the slab pour is the smart move.

New Brunswick Basements can match you with experienced local contractors who handle underpinning and bench footing work in the Moncton area — get matched for a free estimate to get eyes on your specific foundation before committing to either approach.