How do I keep doors from sticking in humid weather?

Why doors stick when it is humid

Wood takes up moisture from the air and swells, then gives it back as the air dries. Wood expands and contracts with changes in heat and humidity. The edge that was fine in February starts to rub in August. So keeping doors free is a matter of two things: controlling humidity in the house, and sealing the wood so it takes up less.

Control the humidity first

EPA's moisture guide advises you to keep indoor humidity below 60 percent (ideally between 30 and 50 percent) relative humidity.^[1] A small humidity meter from a hardware store shows where your house sits. If it reads high all summer, use air conditioners and/or de-humidifiers when needed.^[1]

Also look for the source. If you see condensation or moisture collecting on windows, walls or pipes, act quickly to dry the wet surface and reduce the moisture or water source.^[1] Condensation can be a sign of high humidity.^[1] Bathroom and kitchen doors are the usual first to stick, because they sit next to the wettest rooms: run the exhaust fan during and after showers and keep the door open afterwards to let the room dry.

Seal every edge

A painted face with bare edges takes up moisture through the edges. A door-maker's care guide calls for new primed or unfinished doors to be finished or painted with an even number of coats on all six sides.^[2] That includes the top, bottom and the recesses cut for hinges and latch. The reason is simple: changes in moisture levels can cause damage.^[2]

Use paint or varnish for this rather than relying on primer alone. The edges that matter most are the ones nobody sees: the top and bottom. Take the door off its hinges, stand it on a pad, and paint the top and bottom edges with the same finish as the rest of the door. If you have recently planed or sanded an edge, seal the raw wood with paint or varnish straight afterwards to reduce the chance of swelling later.

Wax rub marks, do not oil them

For minor sticking, try paraffin, candle wax or a dry lubricant stick. Rub it on the shiny spots where the door touches the jamb. Oil tends to attract dust, so wax is the better choice. Wax costs almost nothing and is easy to reverse, which is why it comes before trimming.

Be patient before you cut anything

It is usually best to get through one dry and one damp season before making permanent changes. A door trimmed in August may not close properly in drier weather, and occasional slight sticking is often normal. If the door really will not close, how to fix a door that sticks walks through hinges, sanding and planing in the right order.

Habits that help

• Keep doors closed or fully latched in humid spells where you can, so they sit in a consistent position.
• Touch up chipped paint at once, before bare wood soaks up moisture.

Stop and call a pro if

• Sticking continues all year. A door that rubs in winter too probably has a hinge or frame problem, not humidity.
• The humidity will not come down. Persistent condensation, musty smells or visible mould point to a moisture source that needs finding, not a door repair.
• The jamb is soft, cracked or rotted. Screws will not hold in rotted wood.
• The job has grown past a small repair. Virginia requires a contractor's licence when the work is valued at $1,000 or more.^[3]

Getting help in Virginia

If a door ends up needing real work, read how much it costs to fix an interior door in Virginia and whether to repair or replace an interior door. More home repair answers are on the Home Repair answers page, and you can browse local pros in Doors and Windows pros on Loclis.

When you are ready, describe the door once and licensed local pros quote it.