Is Your Deck Ready for Winter? Five Things to Check Before Snow Sits on It for Three Months

Decks fail in spring, but the damage happens in winter. Snow load, freeze-thaw, and salt do their work from December to March, and a deck with a weak spot in October is a deck with a hole in April. Here is the ten-minute walk-through we do before every winter.

1. The ledger board

This is the board that attaches the deck to the house, and it is where most deck failures start. Look at it from underneath. If it is fastened with nails instead of lag bolts or structural screws, that alone is a reason to call someone. If there is no flashing between the ledger and the house, water has been getting into the rim joist every time it rains. Push a screwdriver into the ledger near the bolts; if it goes in easily, the wood is rotting.

2. Posts where they meet the ground

A post sitting directly in soil or in a concrete pour wicks water and rots from the bottom. Properly built posts sit on a metal base above the footing. Check for softness at the bottom six inches and for posts that have shifted or lean.

3. Railings

Grab each section and push hard. Massachusetts code calls for a railing to take 200 pounds of sideways force at the top. A railing that moves more than an inch has loose or rotted post connections. This is the one that hurts people, and it is the first thing a home inspector flags when you sell.

4. Decking boards and fasteners

Walk the whole surface. Boards that feel spongy, cup badly, or have splits running through the screws need replacing before snow sits on them. Popped nails and screws catch snow shovels and bare feet. Grey, fuzzy wood is weathered but may be sound; black, soft wood is not.

5. Stairs and stringers

Stair stringers are cut from a single board and are the thinnest structural piece on the deck. Check the bottom where they meet the ground or pad, and check the notches for cracking. A stringer that has started to split at the notch will finish the job under a snow load.

Repair or replace

If the frame is sound and the problems are surface boards, a railing section, or a few fasteners, repair it now and get another decade. If the ledger is rotted, the posts are soft at the base, or more than a third of the boards are gone, the honest answer is a rebuild. On a rebuild we use pressure-treated framing rated for ground contact, structural screws, proper ledger flashing, and either composite or treated decking depending on what you want to maintain.

Before the snow

Keep the deck shoveled through the winter, especially near the house, and do not pile the shoveled snow against the railing. Skip the rock salt on wood; it eats the fasteners. Sand or calcium chloride is kinder to a deck.