How To Fix Draughty Sash Windows

Old, draughty sash windows can really spoil the enjoyment of a period home. Not only can they stick in their frame or rattle in the wind, but many people end up watching their hard-earned money disappearing out of the window due to unnecessarily high heating bills.

Over the last century, thousands of beautiful sash windows have been ripped out of Victorian and Edwardian homes and replaced with incongruous plastic or metal-framed alternatives, because for all their elegance and craftsmanship, they’re just not serving the purpose any more.

This is a sad loss and an unnecessary one. The idea that all sash windows are draughty, cold and difficult to maintain is a myth.

Replacing your windows with new period style, timber, double-glazed sash windows offers all the energy-efficiency required by today’s building regulations, reducing heat loss by as much as 75%. They will also last a lifetime with very little maintenance.

As a temporary solution, even old sash windows can be brought up to scratch with some relatively simple fixes, such as draught-proofing and double-glazing. For a relatively modest outlay you can benefit from reduced heating bills, no rattles, less noise from outside and a barrier against dust and pollen.

Assessing your sash windows problems

Common problems with old sash windows include rotten timbers, cracked putty, worn sash cords, unbalanced weights and failed joints. Frames and sashes that have swollen or shrunk will cause sticking, rattling and draughts.

Moreover, old sash windows are single-glazed, giving them much poorer heat insulation properties than modern double-glazed sash windows. The thin original glass allows the cold through so that banks of cold air sit in the room, meaning that homeowners end up fighting a losing battle to keep their houses warm.

If your sash windows fit this description, you should not rush to rip them out in favour of a different kind of window. Replacing with modern sash windows will give your home a brand new lease of life, whilst still maintaining the statement grandeur of a period building.

However, if you are not yet ready to completely overhaul your draughty sash windows, there are a number of draught-proofing fixes that can be performed on existing frames. This can be quite complicated work and does carry some risk of further damage if not executed by a professional – particularly with very old frames. As such, we always recommend that you seek help from experienced draught-proofing and window fitting professionals.

DIY sash window draught-proofing

The biggest problem with old sash windows is draughts. As neglected timbers have shrunk over the years, gaps will have appeared and winter winds will roar through them into your house. But there are plenty of DIY fixes you can apply to block out the draughts.

The simplest sash window draught-proofing solution is to fix the window shut and fill the gaps with flexible filler. Check the putty around each pane too. Where it is loose, dig it out and reseal it with fresh putty.

Fixing and sealing your window is a fairly drastic solution, though, and doesn’t leave you with the pleasure of a fully functional sash window. A more practical DIY draught-proofing option is to use flexible draught excluder strips, which you just roll out and push into the gaps. Adhesive sealer strip on the bottom and top frames will help the draught-proofing too.

Flexible strips will allow you to open and close the window but after a while the strips will begin to come off, so you’ll need to replace them often. Resealing the panes doesn’t overcome the single-glazing issue either. If you have a very high level of DIY skill, you can rout out the rebates and re-glaze the window with double-glazed panes. However, another drawback with DIY draught-proofing is that you can over-seal your windows. Make your windows completely air-tight and you will create the perfect environment for dampness and mould to take hold. Building regulations require a degree of ventilation in every room, especially if the room contains gas appliances like cookers or fires.

New windows for old – replacing your sash windows

If you have seriously draughty sash windows that have suffered years of neglect and are beyond repair, it is time to look at replacements. Brand new timber sash windows are better than ever, offering a level of heat-efficient double-glazing, draught-proofing, ventilation and security that an old sash window will never match, even after professional restoration.

The build quality of new sash windows also means they are more durable and easier to maintain than old sash windows.

The quality and efficiency of modern sash windows is underlined by their increasing use in new build housing, bringing character to modern residential architecture that went missing for decades.

For period homeowners who want to preserve the character of their property but also want the comfort and energy efficiency of a modern home, high-quality replacement sash windows offer the best of both worlds.