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Painting your Sash Windows

We’ve been designing, restoring and decorating sash windows in Kent for many years, so that we continue to preserve the art of these beautiful parts of our architecture. Paint is the final touch that will bring your sash window to life. Although the majority of sash windows owners prefer classic white, you’re more than welcome to get creative and apply your own personality through your choice of colour! Modern paints are pretty good at not only adding vibrancy and quality of finish, but also protecting the frame itself from the elements. Paint shouldn’t have to be applied very frequently, but it is important to check for cracks and gaps that appear, such that you can cover them for continued protection of the frame.

Historic Windows

Many older windows show evidence of multiple coatings over time. That is, over-coating, where the previous layer of paint was not removed in the meantime. This layering is important for the historical timeline of sash windows and how the technologies evolved. With these old windows, it has been possible to remove a small section of these paint layers and perform specialist analysis. The colours and materials can be observed, giving a picture of the history of the building in which the window was set. An interesting side effect of this kind of analysis, is that seeing the results and effectiveness of historical techniques, means that changing from a modern to a traditional paint scheme can be justified.

Choosing Paint

Lead-based paint was historically used. The added lead reduced drying time, increased its durability and resistance to the elements. Unfortunately, we know how bad the health effects can be from exposure to lead-based paint. In general, we think lead-based paint should be avoided except in exceptional circumstances, or where an expert knows how to avoid issues. It is, in fact, still available under licence in the UK. For example, with historical buildings that need restoration and/or maintenance, it is generally preferred to use similar products to those originally used.

Nowadays, there are a huge range of specific types of paint that serve specific functions. What do you need to consider when choosing paint? Compatibility, maintenance and aesthetics are good to consider. Compatibility is relevant where repainting. For example, some paints will adhere less well when repainting over a fading or cracked layer. Different paints give different finishes, and this will come down to personal preference. Cost might be another factor, but paint is pretty cheap these days. Remember, some paints are part of entire systems, where the compatibility of all the layers (primer, finish etc) is specific to the system. Follow the manufacturers instructions to get the correct number of coats and give them ample time to dry.

Preparing Surfaces

Before painting, thoroughly clean and dry the surface. For timber frames, loose paint, wood decay and anything else interfering with the quality of the surface needs to be dealt with first. Once any loose paint has been removed, the frames can be gently sanded to prepare a nice, smooth surface. If dealing with old windows, be careful with coatings of lead-based paint. Removing them without care or understanding the health implications can lead to adverse health effects. Lead-based paint layers should only be dealt with by a professional with experience of handling said materials.

Rust is a problem on metal frames and will need to be removed before attempting to repaint. If the rust is particularly aggressive, it may be quite a big job to restore the frame to a suitable condition. A professional should be able to deduce whether the frames are salvageable or whether new ones are needed. In order to prevent rust in the future, metal frames should be galvanised, that is, coated with a protective layer of zinc to prevent moisture from reaching the ferrous metal. For ungalvanised frames, protective primers that contain zinc should be applied first. If needed, the metal can be sanded similarly to wood, to create a more even surface with better adhesion. If painting while the window is still in place, care must be taken to ensure paint isn’t applied anywhere it shouldn’t. For example, make sure the cords are well out of the way to avoid getting paint on them, otherwise it will be incredibly difficult to reverse!

Painting Should be Fun!

This all sounds very serious! But in fact, applying a nice new layer of shiny paint to lift your sash windows to their upmost majesty is incredibly satisfying. Especially as sash windows experts, we love the feeling of transforming a worn-out and decaying window into something good as new, that still retains the personality and feel of the original. The process can be time consuming, especially if we have to go deeper than originally thought to fix something like rust or wood decay. But ultimately, a restored and repainted sash window is a wonderful thing and should last for many years to come.

Until next time
TR Carpentry.

TR Carpentry

TR Carpentry,
4 Bayfield Road,