Interior Window Frames

The inside of windows can get a bit grubby over the years due condensation washing dust down the glass which collects in the gap between the glass and the lower glazing bar. This can often get infected with mould growth, as it is an ideal environment - wet in the morning and dry and warm during the day. This must be cleaned up and treated with a Multi-Surface Fungicidal Wash before painting.

Essential tools and preparation advice

The window frame must be clean, sound and dry. Scrape back any loose, flaking paint to a firm edge. It is important to clean out all cracked and defective putty between the glass and the frame. It tends to become brittle with age and can fall out. Scrape out all the loose material using a suitable tool. Either a triangle shaped Shave Hook or a small Chisel Knife (like a small wallpaper stripping knife) will be ideal. If you invest in a few basic, good quality tools and look after them, they will last you a lifetime.

You will need to fill any gaps around the glass before you can paint the window, using a suitable Multi-purpose Putty. Use a proper Putty Knife for this purpose. Get a small amount of the putty in your hands and roll it into a small ball to get it nice and pliable. Press the putty into the gap using the putty knife and smooth off and remove the excess. Leave the putty to harden thoroughly before painting.

Once all the preparation is done and the existing paint has been sanded down and dusted off (always wear a suitable face mask when dry sanding), any areas of bare wood must be primed.

Painting advice

When applying the paint to normal opening Windows, it's best to paint in the morning to maximize the drying time. Depending on drying conditions this will enable you to close the windows at night. If you can, remove the stay and catch before you paint the window (leave in a screw to use as a makeshift handle whilst painting).

Window frames should be painted in a certain order to achieve the best results. Also, this will make painting the window easier.

  1. Glazing bars

  2. Top and bottom horizontal rails

  3. Inside vertical rails

  4. Outside edges

  5. Outside frame

"Cutting in" around the glass in windows is a lot easier than most people think and it is a lot better than using masking tape or paint shields. You can buy special, small paint brushes that have bristles with an angled edge. These are ideal for any cutting in job. Don't over-load the brush with paint, hold it like a pen and start from one corner to paint a straight line. Start just below where you want the edge to be and slowly work the paint up to the required line. Never have too much paint on the brush at a time, as this is when it goes everywhere. If the edge is not quite straight then you can simply go over this area again to even it out. If you find that the paint has gone too far up the glass, then simply get a wallpaper stripping knife and pull a piece of clean, lint free cloth tightly over the end and use this to carefully wipe off the excess paint. If you take a bit too much out then just cut in that area again. The important thing is to work slowly and carefully. The more you practice the better and quicker you will become. This technique applies to any cutting in.

The alternative is to spend ages sticking masking tape all over your windows and hope that you have got it straight. When you remove the tape there is the risk of pulling more paint off than you intended!!

Sash windows can be a little more awkward to paint than normal opening windows, but following the sequence described below will enable you to get a good result: Slide the outer sash down a little and raise the inner sash slightly, leaving a gap top and bottom.

Paint the glazing bars and the surfaces of the inner sash including the top surface of the meeting rail and the underside of the bottom rail. Then paint what you can see of the outer sash, including the face (but not the underside) of the meeting rail.

Now slide the outer sash up, but not quite closed, and lower the inner sash by gripping it from the outside so that you don't touch the wet paint. You can now complete the painting of the outer sash, omitting the top surface of the top rail. Ideally you should leave the sashes in this position until dry.

Pull the sash cords out when you are painting behind them (painting the cords will effect how well they work and how long they last); paint the pulley housing but not the pulley itself, otherwise it will jam and the sashes will not run easily. This all sounds a bit complicated but if you look at the window first and practice moving the outer and inner sashes as described it will all make sense.

If the window has been painted badly in the past and does not open it will require a lot of work to sort it out. This is when it is worth paying a specialist sash window company to refurbish them properly. If you have a period house it is worth the cost and effort, as the original windows will always add value to the house.

Painting old metal window frames is much the same as for wood except that you prime any bare areas with Dulux Primer. When filling the gap between the glass and metal frame, make sure that you use a Multi-purpose Putty suitable for both wood and metal. Please note that this advice does not apply to Anodized Aluminium (the metal replacement double glazed windows), as these cannot be painted.