Sash windows add charm and character to a building, but they require maintenance to stay looking great. To keep them in top condition, you should paint sash windows every four years, although this can vary depending on weather exposure. Here’s how to paint a sash window properly:
Before painting your sash windows, there are a few things you need to check. Firstly, check the window putty, and if it’s loose, remove as much as possible. Secondly, check for rot, and if any is present, remove it and apply a wet rot hardener to the affected area.
If the rot is minimal, it can be repaired without the need for a carpenter. Once the rot has been addressed, you can begin painting your sash windows. You will need a few tools, including a screwdriver, a tungsten carbide scraper (if available), filling knives (2″ and 1″), a putty knife, sandpaper (grades 80, 120, 150, 180, and 240), a sash paint brush, and a small paint kettle. The materials required are aluminum wood primer, 2-pack filler, linseed oil putty, undercoat, topcoat (gloss is the hardest wearing), methylated spirits, and masking tape.
Begin by removing any loose putty and cleaning out the exposed area, which may be damp. If the area is damp, allow it to dry out completely. Next, scrape out any loose rotten wood and leave the sash window exposed in the air for a few days to dry out further. Once dry, apply a wet rot hardener to the affected area, which will harden the wood and allow you to fill it without the filler falling out.
Use a putty knife to replace any window putty, and then fill any holes with 2-pack filler. Sand the surface until it’s smooth, removing the sheen from the old paint. Give it a good dusting and wipe it down with methylated spirits to remove any residue. Linseed oil putty takes up to six months to cure properly, but you can use 2-pack wood filler, which cures in about 30 minutes and is ready to paint.
Once everything has been filled, sanded, and cleaned, you can start spot priming all exposed wood and fillers with an aluminum wood primer. The primer is a silver-grey primer that protects your woodwork from the elements. Leave it to dry overnight before applying two coats of oil-based undercoat followed by one coat of oil-based gloss, such as Sikkens Rubbol Satura.
Finally, before you paint, remove the sash ring hooks and fasteners. Push the bottom sash up to the top and pull the top sash down to the bottom to allow you to paint the top of the bottom sash. That’s it – now you can paint your sash windows with ease.
If you would like professional help with painting your sash windows, contact PaintinginColour today!
Robert Martinak is a Painting Technology Specialist with over 30 years of experience in the field. He is based in Dublin, Ireland and has extensive knowledge and expertise in the application and management of painting projects.