What does it cost to parge foundation walls that are below a wooden deck that needs temporary removal?

Parging foundation walls under a deck that requires temporary removal typically costs $2,500-$6,000 for the parging work plus $800-$2,500 for deck removal and reinstallation, depending on the deck size, complexity, and foundation area to be parged. The total project cost ranges from $3,300-$8,500 for most GTA homes.

Deck removal and reinstallation adds significant cost because the contractor must carefully dismantle the deck structure to preserve materials for reuse, store components safely during the parging work, then rebuild to original specifications. Simple ground-level decks (8x12 feet) cost $800-$1,500 to remove and reinstall, while elevated decks with railings, stairs, or complex framing cost $1,500-$2,500. If the deck structure is old or deteriorated, some components may need replacement during reinstallation, adding $500-$2,000 depending on what needs to be renewed.

The parging work itself follows standard GTA pricing of $12-$18 per square foot for polymer-modified parging on the exposed foundation area. However, foundation walls under decks often present additional challenges that increase costs. These walls frequently have moisture damage, efflorescence, or existing parging failure because deck drainage issues have directed water against the foundation for years. Poor drainage under decks also means the foundation may need more extensive surface preparation, including pressure washing to remove mould or algae growth that thrives in the damp, shaded environment.

GTA climate considerations make deck removal projects particularly worthwhile for parging. Foundation walls under decks are protected from direct sun but often stay damp longer after rain, creating ideal conditions for freeze-thaw damage to existing parging. The confined space under most decks also makes it impossible to properly apply and cure parging without removing the deck structure. Attempting to parge in cramped conditions leads to poor application technique and inadequate curing, resulting in premature failure.

Timing and seasonal factors significantly impact project costs and scheduling. Spring (April-May) is peak season for both parging and deck work in the GTA, so booking early or scheduling for late summer can sometimes yield better pricing. The entire project requires 7-10 consecutive days above 5 degrees Celsius for proper parging curing, so weather delays can extend the timeline. Most contractors prefer to complete deck removal, parging, and deck reinstallation as one continuous project to minimize disruption and ensure proper curing conditions.

Additional considerations that may affect costs include upgrading deck drainage during reinstallation (adding proper slope, installing deck membrane, improving downspout connections), addressing any discovered foundation issues (cracks, settling, waterproofing needs), and coordinating with other trades if electrical or plumbing runs under the deck. Many homeowners use deck removal as an opportunity to upgrade the deck structure, add proper waterproofing, or install heated cables for winter ice prevention.

When to hire professionals - this type of project absolutely requires experienced contractors. Deck removal requires carpentry skills to preserve materials and ensure proper reinstallation, while foundation parging requires masonry expertise for surface preparation, material selection, and application technique. Attempting DIY deck removal often damages components that then need replacement, and improper parging application in the confined space under a deck almost always fails within 2-3 GTA winters.

Get quotes from contractors experienced with both deck work and foundation parging, or coordinate separate specialists through a general contractor. Always verify WSIB coverage for both the carpentry and masonry portions of the work.