Helpful video reference. The video above is "How to Prepare and Paint Wooden Window Frames and Sills" from Homebaseuk. It is a practical walk-through of the technique, worth watching for the hand movement rather than just reading about it.
Prepare the frame
Wash away condensation residue and dirt with a mild detergent, scrape off loose paint, and sand the frame lightly. Fill cracks and dents, then sand flush. Pay attention to the bottom rail and sill, where water collects and paint fails first.
Frames in homes built before the 1960s can have lead-based paint. Wet sand, control dust and avoid dry scraping.
Deal with mould or damp wood
Black spotting on the frame is mould from condensation. Clean it with a suitable fungicidal wash, never mixing products, and let the wood dry thoroughly. Soft or spongy timber needs repair before painting.
Prime any bare timber so moisture cannot get back in through unprotected wood.
Mask the glass
Run low-tack tape along the edge of the glass, leaving a tiny gap of about 1 to 2 mm so the paint seals onto the glass and keeps water from creeping behind. Alternatively, cut in freehand with a small angled sash brush.
Keep the tape straight, because it is the edge of the paint line that everyone will see.
If the old sealant around the glass has cracked or shrunk, rake it out and renew it before painting, because paint will not bridge a failed seal for long.
Work in order
Open the window slightly. Paint the moving parts first, such as the casement or sashes, then the fixed frame, then the surrounding architrave and sill. Use thin coats so nothing bridges the gap and glues the window shut.
Move the sash a little while the paint is still tacky so it does not stick in the frame. Keep the brush lightly loaded, and wipe any paint that lands on the hinges or catches straight away.
Finish and cure
Let the coat dry as stated on the tin and apply a second one if needed. Remove the tape when the paint is touch dry and leave the window slightly ajar until it has hardened.
What this means in Folkestone
Sash and casement windows in Folkestone's Georgian old town and the Victorian villas on the Leas and Bayle often have many layers of paint and a lot of detail. Sandgate seafront houses see strong sunlight and condensation, so frames there tend to need a good clean before painting. Terraces in Cheriton and Morehall usually have simpler frames that are quicker to complete.
Common mistakes to avoid
- Painting the sash shut by loading the edges with too much paint.
- Leaving condensation mould in place and painting over it.
- Using wide masking tape that covers the paint-to-glass seal.
- Painting in cold, damp conditions so the coat takes days to harden.
Quick answers
Which finish is best for window frames?
Satinwood or gloss, because both wipe clean easily. Water-based versions dry faster and yellow less.
Can I paint frames with the window closed?
Better to keep it open slightly while painting, then move it a little as it dries.
How do I clean paint off the glass?
Leave it to dry, then lift it carefully with a fresh razor scraper held flat against the pane.
Prefer we do it?
Room painting from £325, standard trade paint and labour included. See our price guide, our interior decorating page or get a fixed quote.