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Internal doors

Oak internal doors

Oak internal doors come two ways. Engineered doors carry a real oak veneer over a stabilised core, so they hang straight and stay straight. Solid oak is cut from the timber itself and moves with the seasons. Both are sold unfinished for you to finish, or ready-finished to hang straight away.

Oak is the default answer when someone wants their doors to look like timber rather than like paint, and it is the finish most people picture when they say they want wooden doors. What almost nobody is told at the point of buying is that two very different products are sold under the same word.

Grain, colour and figure vary from leaf to leaf. That is oak behaving normally, not a fault, and it is the reason a set of oak doors bought together looks more deliberate than the same doors bought one at a time over a year.

Showing all 3 doors

Engineered oak or solid oak?

Most oak doors sold in the UK are engineered. The word makes them sound like the compromise option, and for stability they are the opposite.

How the two constructions differ in use
Engineered oakSolid oak
ConstructionOak veneer over a laminated, stabilised coreSolid oak boards or staves
MovementVery little — the core resists twist and cuppingExpands and contracts with humidity through the year
Gaps to allowStandard gaps around the leafA slightly more generous gap, particularly at the top and the closing edge
TrimmingLimited by veneer thickness on the edgesMore forgiving, but still limited by the manufacturer
Typical costLowerHigher
Best forMost houses, and anywhere with underfloor heating or big humidity swingsPeriod properties where the honesty of solid timber matters

Finishing an oak door

An unfinished oak door is not a finished product. It is raw timber that will drink moisture out of the air until you seal it, and an unsealed door in a new plastered room is the classic way to end up with a leaf that no longer fits its frame.

Seal every face and every edge, including the top and the bottom. The top edge is the one that gets forgotten, because nobody can see it once the door is hung, and it is usually the edge the manufacturer names in its guarantee conditions. Check the finishing instructions supplied with the door before you open a tin.

  1. Hang the door dry first, mark and trim to fit, then take it back off.
  2. Sand lightly along the grain and remove all dust.
  3. Seal all six surfaces — both faces, both long edges, the top and the bottom.
  4. Build up the coats the manufacturer asks for, sanding between them.
  5. Only fit ironmongery once the finish has properly cured.

Matching oak doors across a house

Oak varies by batch. If you are doing a landing or a whole floor, order the doors together and finish them together with the same product from the same tin. Doors bought six months apart and oiled with whatever was left in the shed will read as two different sets, and there is no fixing that afterwards short of stripping them.