Composite doors don’t warp the way timber doors do, because there’s no solid wood absorbing moisture and swelling. What they can do, in the wrong conditions, is bow slightly in strong sunlight, usually a dark-coloured door on a south-facing elevation in high summer. It’s worth understanding, because it’s avoidable.
Why a composite door can bow in heat
The outer skin absorbs sunlight, and a dark skin absorbs a lot of it. On a hot afternoon a black or dark blue door facing the sun can get hot enough to be uncomfortable to touch. The outside face expands slightly while the inside face, in a cool hallway, doesn’t. The result is a small bow towards the sun. In most cases it’s temporary and the door straightens as it cools in the evening. Where it becomes a problem is if the door is repeatedly closed on the latch only, so nothing is holding it straight while it’s hot, and the movement gradually sets.
Manufacturers build in a tolerance for this, and doors that bow beyond it are normally covered under guarantee, so keep the paperwork.
How to prevent it
- Lift the handle every time. Throwing the multi-point lock engages every locking point up the height of the door and holds the slab flat against the frame. This is the single most effective thing you can do, and it also keeps the seal tight against draughts.
- Think about colour on a south-facing door. Lighter colours reflect heat. If your heart is set on black or anthracite and the door bakes all afternoon, tell us, because some door skins are made to reflect heat better than others and it’s worth specifying the right one.
- Don’t leave it standing open in full sun. An open door exposes its thin edges to direct heat and can be awkward to close for an hour afterwards.
- A canopy or porch makes a real difference on an exposed elevation, and looks the part.
What about moisture and cold?
Composite doors don’t absorb water, so winter swelling isn’t a thing, and the sealed edges keep the core dry. If a composite door ever sticks in winter, it’s almost always the frame or the fitting, not the slab.
Our composite doors come in a wide range of colours. If you’ve a south-facing front, ask us which finish we’d put on it; we’d rather tell you now than see you back in three years.
Thinking about a composite door? We supply and fit them across Wolverhampton, and you deal directly with us, the owners. Call 01902 633355, message us on WhatsApp, or design your door online and we’ll put a proper price together for you. Finance options are available if you’d like to spread the cost.