Every outdoor construction project in Canada faces two certainties: the weather will interfere, and the site will contain at least one condition nobody anticipated. The question is not whether surprises will occur. It is whether your contract and your relationship with the contractor are structured to handle them without escalation.
Weather and Scheduling
Canada's construction season for outdoor decking varies dramatically by region. In southern Ontario, work can run from late April through October. In the prairies, the window narrows. On the coast, rain interruptions are constant but rarely stop work entirely. Wherever you are building, ask the contractor how they handle weather delays. Specifically: How will they communicate a delay? Will the crew move to another job and come back, or will your project stay first in queue? What happens if a delay pushes the project past a date that matters to you (a family event, a sale of the home)?
These are not anxious questions. They are scope questions. Seasonal realities mean that building contracts should acknowledge weather impacts and specify communication expectations rather than handling delays informally.
Site Surprises
The most common site surprise on a deck replacement project is discovering that the existing substructure — the posts, beams, or joists underneath the old deck boards — is in worse condition than expected. Rot, insect damage, or inadequate original construction can all surface once the old boards come off.
Your change-order clause handles the financial side of this. But you should also prepare for it emotionally: a site surprise does not mean the contractor made a mistake or that the project is going off the rails. It means the project encountered reality. The right response is to document what was found, agree on a revised scope and price in writing, and proceed. The wrong response — for either party — is to improvise verbally and sort out the money later.
What to Document During Construction
Keep a simple record of the project as it unfolds. Photograph the site before work starts, during key milestones (footings poured, framing complete, decking laid), and at final completion. Save every written communication. If the contractor proposes a change or you notice something that concerns you, put it in writing — even a text message creates a record.
This is not adversarial documentation. It is the same discipline that professional project managers use on every construction project. If everything goes well, your photos are a satisfying before-and-after. If something goes wrong, your records are the difference between a conversation and a he-said-she-said.
Before the crew arrives on day one, photograph the existing site from multiple angles, including any adjacent landscaping, fencing, or siding that could be affected by construction activity. This baseline protects both you and the contractor if a damage dispute arises later.