Deck Maintenance Before Winter: A Boston Checklist

Why freeze and thaw is so hard on New England decks

Water expands about nine percent when it freezes. When that happens inside a screw hole, a checked board, or the end grain of a joist, it pries the wood fibers apart a little every cycle.

Boston sees dozens of freeze and thaw cycles in a normal winter, and coastal air keeps things damp between them. That is the whole story behind soft boards, popped fasteners, and railings that wobble by spring.

The fall deck checklist

Run this before the first hard frost. Most of it takes a broom, a screwdriver, and an hour.

• Clear every leaf out of the board gaps, trapped leaves hold water all winter
• Sweep and wash the surface, then let it dry for two dry days
• Push a screwdriver into the boards near the ledger, the stairs, and any post base, soft wood means rot
• Reset or replace popped nails and stripped screws, a raised head catches a shovel
• Check the ledger flashing where the deck meets the house, this is the most important connection on the whole structure
• Grab each railing post and shake it, movement now becomes failure under snow load
• Look under the deck for standing water, mud splash, and any post sitting directly in soil
• Reseal or restain if water no longer beads on the boards
• Move planters and furniture off the boards or onto feet so nothing traps moisture

The water test that tells you if you need to reseal

Pour a cup of water on a few spots. If it beads up, your finish is still doing its job. If it soaks in and darkens the board within a minute, the wood is drinking, and it will drink snowmelt all winter.

Reseal while you still have a two day dry stretch above 50 degrees. Once nights drop into the 40s, most deck coatings will not cure properly and you are better off waiting for spring.

Repair now or wait until spring

Some things can safely wait. Others get much worse and much more expensive over one winter.

Snow removal without wrecking the boards

Use a plastic shovel and push with the boards, never across them. A metal blade will gouge wood and shred a composite surface.

Skip the rock salt. Chloride based ice melt corrodes fasteners and connectors and can damage the wood surface. If you must use something, use a product labeled safe for decks, and use less than you think you need.

Signs the deck needs more than maintenance

If the ledger board is soft, if a post base crumbles when you push it, if the deck bounces when you walk it, or if the whole structure leans away from the house, stop maintaining and get it looked at.

Those are structural issues, and snow load is real weight. The American Wood Council publishes the prescriptive residential deck construction guide that most inspectors work from, and it is a useful reference for what a safe connection is supposed to look like.

We handle this work through our deck repair service, from board and railing replacement to post and framing repairs, across Boston, Newton, Belmont, Milton, and the rest of Greater Boston. If the railings and trim also need paint, read our post on the best time to paint a house exterior in New England before you book it. For everything else on the punch list, see home repairs and handyman services and our post on why hiring a home improvement professional saves time.