Painting Interior and Exterior Window Frames

We are often asked at MPA National Office about where the interior and the exterior painting starts and stops on window frames. MPNZA offers the following advice:

Painting interior window frames and sashes
Generally, when standing inside the room, we paint everything you can see when the window is closed. The sashes should be opened fully and painting should take place to the hinged edge of the sash and the edge of the window frame where the hinge is secured. This is the same for both side hinged sashes as well as top hinged sashes.

Painting exterior window frames and sashes
Again, when standing outside, we paint everything we can see when the window is closed. The sashes should be opened fully and painting should take place to the bottom edge, leading edge and in some cases the top edge of the sash. The rebate where the sash sits in the frame should also be painted where the top, bottom and leading edges of the sash meet.

On exterior sashes best trade practice would also include painting of the putties so that a good seal of paint is achieved between the putty and the glass. In most instances this seal will impinge the glass approximately 2mm. This can be done by free hand cutting in or by the use of masking tape. The seal allows rain water to run down the glass, over the putties and away and stops water getting behind the putties and between the glass which will result in extended life of the painted surfaces.

A general specification for painting windows would include ensuring the sash fits smoothly into the frame, planning of the sash may be required to ensure a correct fit. Cleaning the surface before any painting takes place and spot priming of bare timber and metal with a suitable primer would also be required.

This would be followed with a full undercoat and 2 top coats of paint. Water based enamel paint coatings are a particularly good product to use when painting interior and exterior window frames and sashes. These coatings provide good anti blocking properties to help prevent the window sashes sticking to the frame when painted. Water based enamel is hard wearing, does not yellow with age, is low odour and brushes wash up in water.