Retrofitting double glazing on sash windows is a specialized service that we offer to clients who want to enjoy the benefits of double glazing without having to replace their original timber frames. Our service involves upgrading your existing sash windows with double glazed units, which can significantly improve your home’s energy efficiency, reduce noise pollution, and enhance security.

Our retrofitting process is more labour-intensive than installing new joinery and requires specialised skills and equipment. After removing your existing windows, we carry out an overhaul and install a draught-proofing system. We then remove the existing glazing and putty from the sashes and use a router to manually rebate each sash to increase the width and depth to accommodate the double glazing units. This is a crucial step, as it allows us to hide the black sealant used when the double glazed units are installed, preventing unsightly black lines from being visible internally.

We offer a range of double glazing options, and the choice of glazing will depend on the depth of your sashes. For windows that have glazing bars, we install a single unit per sash and laminate the existing (original) glazing bar internally and a hardwood external glazing bead. This gives the visual effect of multiple panes, though it will be a single unit. This method is necessary because the width of the glazing bar will not allow for the rebate and enough timber externally to install multiple panes. We use toughened double glazing, which means we cannot afford contact between each pane as they will ‘blow’ or shatter. Additionally, when installing the glazing bead, we would be nailing towards the newly installed double glazed units.

After rebating, we fill, sand, and prime the existing sashes, leaving them to dry. We do not offer a new sash finish, but we will tidy them up for you. Once dry, we install each double glazed unit using sealant internally and externally to ensure maximum energy efficiency and weatherproofing. We also adjust any operational windows to ensure they work as well as old windows can, and any fixed panes will be installed as such.

Once the retrofitting process is complete, decoration will be required within 6-8 weeks. We recommend prioritising internal painting during winter months to ensure a sightline is painted for when condensation hits. The external can survive slightly longer as decorating during very wet times of the year can sometimes affect the lifetime of the paintwork.

Retrofitting double glazing on sash windows is a cost-effective solution that can enhance the look, comfort, and energy efficiency of your home. If you have any questions about this service or would like to request a quote, please do not hesitate to contact us. We have a team of experts who are ready to assist you with your retrofitting needs.

If you have any questions about this service or would like a quote, please feel free to contact us on the enquiry form or email [email protected].