Why do old doors fail?
It’s some test, the ‘Test of Time’ and doors are no exception. Wooden front doors have been around as long as we’ve lived in buildings. In the right conditions, wood is a very durable material, lasting hundreds of years. It is resistant to heat, frost, corrosion and pollution. What wood doesn’t like is movement caused by frequent changes in temperature and humidity; otherwise known as ‘sunlight’ and ‘driving rain’.
Period front doors have been constructed in a similar way for around two thousand years. Separate pieces of dried timber are joined together using mortise and tenon joints assisted by glue and wedges. The glue bonds the surfaces and wedges are driven-in to provide frictional resistance to movement. Unsealed timber will always gain or lose moisture until it is in equilibrium with its surroundings. Changes in temperature and humidity cause volume changes which are not equal in all directions. They set up stresses which can only be relieved by movement: either the timber splits along the lines of its grain or cracks develop at the joints as the pieces separate. Once a crack opens, moisture can penetrate deeper and further, harmful, movement is inevitable.
We ask a lot of our doors, especially the external ones. They experience all the vagaries of our climate on one side and the warmth and relative dryness of a centrally-heated home on the other. Not that life is necessarily very much easier for some internal doors. Kitchen doors and bathroom doors are especially vulnerable to the consequences of having a warm and steamy environment on one side and drier, cooler, air on the other. In other rooms, we leave doors open for long periods with a radiator close by, pumping its heat into only one side of the timber.
Noel smiled when he looked at the 100 year old Victorian front door on my house. All this winter I’ve been pushing draught-excluders into the gaps around it – largely to no avail – and then on damp days it fits so snugly into its frame that I can hardly get it open. Which is why I had called him round.
“This door needs planing to stop it sticking,” I told him.
“Look at the top rail,” he replied. “Can you see how there’s a wedge-shaped gap between the top of the door and the frame; it’s very small at the hinge side, and very wide above the locks?”
Next he pointed to where the door was binding on the step, at the bottom corner, furthest from the hinges.
“These two old hinges can no longer carry the weight,” said Noel. “Over the years, the loops around the central pins have worn away until now they’re more like spirals. That’s why your door sticks and, from now on, this one always will. You need new hinges as well as a new door. Let’s face it, after a century of use they’ve earned their keep many times over.”
“But if I get a nice new door, won’t the same thing happen again?”
“Eventually,” he said, “Yes, it probably will. But if it starts to stick in the winter of 2113, don’t hesitate to call me back.”