Timber Windows | 5 Steps to Remove Mould from Timber Window Sills

Posted on: 21 September 2015

Leakage and condensation on timber windows can cause mould to grow on windowsills. This growing mould can lead to stubborn stains and musty odours in a home. Besides unsightly stains and musty smells, mould can also cause health hazards and breathing problems, so you'll want to get rid of it as soon as you possibly can. Ignoring the mould problem will result in it seeping into the pores of the wood –– eventually requiring replacement. Here are some steps involved in removing mould from timber windowsills. This method will also apply to timber doors and timber sliding doors.

Get Your Supplies Ready

To remove mould, you will need sandpaper, vinegar, ammonia, rag cloth, bristle brush, primer, paint and a paintbrush. Be sure to wear safety goggles, a dust mask and gloves, because removing mould will discharge all types of harmful spores into the air. The acidic properties present in vinegar help it to cut through mould to loosen it from the surface, while ammonia is an excellent household disinfectant that should remove the mould completely from the surface.

(Disclaimer: The use of ammonia cannot be replaced with bleach. Vinegar and bleach combine to make harmful fumes. Additionally, never use ammonia and bleach together, as when combined they also create noxious fumes.)

Cover your Floor and Open the Windows

Make sure you cover the floor under the timber windows with a plastic tarp to prevent falling mould spores from resting on your carpet and other flooring materials for too long. Open the window to give the room proper ventilation during cleaning, so that the mould can fall outside. You'll ideally want to choose a sunny day for the wood to dry quickly.

Spray with Vinegar and Ammonia Solution

In a spray bottle, mix a solution of vinegar and ammonia in equal parts until it reaches half full and fill the bottle to the brim with warm water. Scrub off the remaining mould after sanding with a bristled brush and wipe with a rag cloth. Spray the solution on the mould and let it sit for several minutes, so that the disinfectant solution penetrates into the mould to loosen it from the timber surface. Wipe off the remaining residue with a rag after some time and use a clean damp cloth to scrub the timber surface. Let the wood dry before you close the window.

Sandpaper the Windowsill

If the mould has grown over a long time, the above method should be combined with sanding. Begin by sanding back the paint with medium-grit sandpaper to remove the remaining mould. Once you are done, vacuum the dust created through the sanding process. Repeat the steps for spraying the disinfectant solution and sanding the sill until all the mould disappears from your timber windows.

Apply Primer and Paint

Apply timber-friendly primer and paint once the wooden surface has completely dried from the mould removal process. This will restore your timber windows back to their original look. These can be purchased from a paint or home improvement store. 

Removing mould from timber windows is stress-free when you follow these easy steps. If you need or want new timber windows installed, contact a local professional, such as Johnston Joinery