After another London winter, your deck has taken a beating from freeze-thaw cycles, ice, and moisture. Many homeowners don't notice the damage until it becomes expensive. Here are five warning signs to look for before you fire up the barbecue.

1. Grey, Splintering Wood

When a deck's finish breaks down, UV rays and moisture strip away the wood's natural oils, leaving it grey, rough, and prone to splinters. If your deck looks more silver than its original tone, it's overdue for a professional clean and reseal. This is the earliest and most common sign we see on London, Ontario decks every spring.

Grey weathered deck in London Ontario before professional deck restoration
Before
Beautifully restored deck in London Ontario after professional cleaning and refinishing
After

2. Peeling or Flaking Stain

Once the protective coat lifts, water penetrates the wood fibres directly. This accelerates rot from the inside and means your next treatment won't bond properly until the old finish is removed. Deck restoration in London needs to happen before summer humidity sets in — once moisture is trapped under a new coat, you'll be back at square one.

3. Soft or Spongy Boards

Walk every board and press with your heel. Any bounce or give indicates internal rot — a serious structural issue. Soft boards spread quickly; one or two replaced in spring is far cheaper than a full rebuild in fall. This is one of the most important checks for older London homes where decks may have been neglected for several seasons.

Deck mid-restoration in London Ontario — stripping and cleaning before applying new stain and sealant
Professional deck prep — stripping and cleaning before the new finish goes on.

4. Visible Mould or Mildew

Black or green patches aren't just cosmetic — mould eats into wood fibres and makes surfaces dangerously slippery. A professional soft wash removes it at the root rather than just scrubbing the surface. London's wet springs mean mould growth accelerates fast once it takes hold.

5. Widening Gaps Between Boards

Some gap is normal, but anything wider than a finger means boards have warped or shrunk significantly. Left untreated, those gaps trap debris, hold moisture, and speed up rot underneath. This is particularly common on decks built before 2010 in London-area neighbourhoods like Byron, Westmount, and Masonville.

Final stain and seal stage of deck restoration in London Ontario — long-lasting protection applied by Core Exteriors
The final stain and seal — this is what protects your investment for years to come.

Catching these signs in spring gives you the whole summer on a restored, safe deck. A professional clean, sand, and reseal typically costs a fraction of full replacement — and adds real curb appeal. Core Exteriors provides deck restoration services across London, St. Thomas, Strathroy, and Dorchester.