OK, so the title is a bit misleading, solid oak doors are not living things in the strictest sense of the words but in comparison to other home furnishings, even other types of door, solid oak doors do react and change to their environment more than anything else.
This is due to the porous nature of the wood and its natural tendency to acclimatise to its atmospheric surroundings reacting in particular to changes in temperature and humidity. This is sometimes misconstrued as a fault in the wood but this is exactly as nature intended and as we enjoy the benefits of solid oak so we must accept the nuances of a beautifully natural product.
What's going on then?
Trees like every other living thing on earth need water. The water is transported up through the tree from the roots by capillary action along tiny veins that are throughout the entire structure of the tree. The channels within which the water can travel are microscopic in size and this enables it to quench every part of the tree where and when it is needed. When it is cut down although the tree is dead the characteristics of this porous micro structure remain intact and give the door its ability to balance moisture levels inside the wood and outside in the atmosphere.
There are many reasons for changes in moisture levels or temperature in the home but most notably the weather is an over-riding factor. Obviously a door cannot absorb water at the same rate as a living tree but together with changes in temperature it is enough to cause problems as it expands or contracts in reaction to its surroundings, especially if it is not properly fitted in the first place.
Solid oak doors can be expected to expand and contract throughout their life but particularly in the first year of use as they settle. However, even old doors may change slightly in size when moved to a new location as they acclimatise to new humidity and temperature levels. When new solid oak doors from UK Oak Doors are delivered they are supplied in their rawest form and are at their most susceptible to the elements. This is why it is imperative they are treated as soon as possible after delivery and are only stored in rooms with a dry atmosphere, even wet plaster on the walls may cause moisture problems in some cases. The best way to minimise the effect of the elements is to treat internal solid oak doors with Treatex oils or for external doors use Impranol.
Challenges you May Face with Solid Oak
As a solid oak door expands and contracts this will affect the fit of the door in the frame. Even though the overall door width will only change by a small percentage at the most it is still enough in some cases to affect its use. Gaps between the frame and door may appear where there were none previously or alternatively the door may become tighter fitting in the frame. However, the installation process should take into account the expected small movements the door will experience throughout the year and build these in to the calculations to minimise any problems.
The expansion and contraction in solid oak doors is unlikely to cause problems in most households if the door has been properly fitted but if these natural characteristics are not something you will learn to love then maybe it is better to consider a more man-made variation of door. There are a huge range of engineered doors available without the issues outlined above although it’s worth noting that almost any door will be susceptible to temperature changes to some degree.