London contractors see the same renovation mistakes over and over. Most of them are avoidable — and all of them are expensive to fix after the fact. Here are the seven that cost London homeowners the most money, frustration, and time on deck & patio renovations.
Skipping the permit
Unpermitted decks are flagged at sale and can require demolition. Most decks attached to the house or over 24" require a permit.
Under-sizing footings
Footings must extend below the frost line for your region. Too shallow and they heave every spring.
Choosing the wrong material for your climate
Cheap composite fades in hot climates; PT lumber checks and splinters over time. Match material to your specific conditions.
Incorrect ledger attachment
The ledger connection to the house is structurally critical. Improper attachment is the leading cause of deck collapses.
No drainage plan
Water pooling on a deck or against the house causes rot and foundation issues. Slope 1/8" per foot away from house.
Building beyond the property line
Always check setback requirements before designing. Decks must respect minimum distances from property lines.
Railing height violations
Code requires specific railing heights and picket spacing (no gap larger than 4"). Non-compliant railings require correction after inspection.
The Bottom Line
Most of these mistakes share a common thread: they're caused by rushing decisions, skipping steps that seem optional, or choosing cost savings in the wrong places. A deck & patio renovation starting at $14,250 is a significant investment. Spending an extra $500–$2,000 to do it right protects the other $14K+.
Use the free London Deck & Patio Calculator to get a realistic budget estimate before talking to contractors — knowing the real numbers prevents many of these mistakes before they start.
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