A neat deck photograph rarely includes a close-up of the gaps. Then November arrives, a joint looks wider, and suddenly that little space becomes the only thing you can see.
Identify the board before judging the gap
Trex explains temperature-sensitive spacing and directs installers to the applicable guide. Side spacing, end spacing, and clearance against a wall are different details. A measurement copied from another brand can be wrong for yours.
Keep the useful space useful
Photograph the same joint with a ruler and note the weather. Record whether it is simply wider or whether an end is lifting, rubbing, or losing support. Those are different observations. For the support beneath meeting board ends, compare butt joints and breaker-board layouts. Do not fill the joint with caulk or force boards together to improve a winter photograph; drainage and movement still need somewhere to happen.
Before the next step
- Find the exact board line and installation guide.
- Compare joint type and installation temperature, not appearance alone.
- Have unsupported, buckled, or loose ends inspected.
A deck is allowed to move. Your installation should have a deliberate way to accommodate it. Ask for that explanation before asking for a smaller gap.
Working with timber instead? Pressure-treated board gaps can widen as the lumber dries, so use the wood-specific guidance.