Care and maintenance of timber windows and doors

Fri 06 Jun 2014

Properly cared for, today’s high performance, factory-finished timber windows and doors will last a lifetime – studies by Heriot Watt University, Edinburgh and Imperial College London show that windows made to Wood Window Alliance specifications have an estimated Service Life of around 60 years. And to support this long Service Life, many makers offer lengthy warranties – as long as 30 years on the structural integrity of the frame and typically 8 years on the opaque coating. But to ensure the validity of your warranty, you will also need to keep to a maintenance schedule (check the conditions of your warranty).

Wash the glass regularly

All glass on any door or window needs to be cleaned regularly to avoid a build up of residues that can etch into its surface. Use mild soapy water and a soft sponge. Never use an abrasive sponge or cleaner, which could damage the surface of the glass and the frames. Rinse aid can be used to help prevent any streak marks after drying.

Wash the frames annually 

When you’re cleaning your windows, it’s a good idea to wipe down the frames, removing any dirt or debris from grooves and recesses. This helps keep the surface of the frame free from damaging pollution, keeps vents clear and helps avoid water collecting in areas that could encourage premature failure. Many warranties require the frames to be washed at least annually.

Do not us a power‐wash or garden hose on your windows. This can lead to seal failure, allowing water to enter the frame, which can lead to movement in the wood.

Check and repair the outside of your frames

Check the outside of your frames regularly for any damage to the surface – a good prompt is when you wash the windows. It’s best to make a repair as soon as possible. Wait for the timber to be dry, remove any loose paint, give the area a light sanding, wipe it down, prime any bare areas of wood and then add a good thickness of top coat. Allow to dry for four hours before adding a second top coat. This may also be a requirement of any warranty you have. South-facing windows and doors will tend to need attention first, as they are subject to the greatest exposure to the sun’s UV light.

Clean the inside of your frames

Internally, timber frames need very little maintenance. From time to time it may be necessary to wipe away any grease or dust with a soft cloth and mild soapy water. 

Gaskets and seals

Gaskets and seals are used between fixed and opening components. They create a flush, tight seal to prevent high winds and driving rain seeping through. They need very little maintenance other than the occasional clean with a cloth and mild soapy water.

When redecorating the frames, you can remove the gaskets. Use mild soapy water to ease them back into position.


Door and window hardware should last a lifetime, provided it is well-lubricated and kept clear of dirt and debris. Fixings should be lubricated annually (again, often a stipulation of warranties). In addition, it is a good idea to lubricate them whenever the windows have been washed. Locks can be lubricated by putting oil on the key and inserting it into the lock a few times.

Folding sliding doors and lift and slide doors

These types of door have a bottom running track that must be kept clear of any debris and obstacles that could damage them. Although the tracks are designed so that dust and small dirt particles do not impede their function, they should be vacuumed regularly.


Condensation occurs when warm, humid air meets a colder surface, such as a window. Single-glazed windows are particularly vulnerable to condensation, which can collect on the glazing bars and cause mould and even premature failure.

Very little condensation will occur on double or triple-glazed windows unless the humidity in the room is unusually high – as, for example in a bathroom or kitchen. In these circumstances, keep the trickle vent on your window open, or increase ventilation by using a fan or opening the window for a short period.

In certain conditions, condensation can form on the outside of the glass. This is completely normal and is a sign that the doors and windows are insulating to a very high standard.

If condensation occurs within the glazing unit itself, then the sealed unit is likely to have failed and will need to be replaced. Premature failure of sealed glazing units is almost always due to poor fitting – either putty has been used, or the unit has not been seated on blocks to allow adequate drainage of any water that might enter through the seals.