Adjust the keeps on a draughty uPVC window

Adjust the keeps on a draughty uPVC window so it pulls tight and shuts without gaps.

KW-01Work out why the window is draughtyShut the window fully and run your hand around the frame to feel for cold air. Check if the sash sits flush all the way round, or if one corner stands slightly proud. If the handle needs a lot of force to lock, or locks easily but still lets a draught through, the keeps need adjusting rather than the whole window replacing.

KW-02Get the right tools togetherMost uPVC keeps adjust with a 4mm Allen key, but some use a Pozidriv screwdriver instead. Check the fixing screws on your keeps before you start so you bring the right one. Keep a cloth handy for wiping off old grease.

1 each · Allen key set (2-10mm)

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1 each · PZ2 Pozidriv screwdriver

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1 each · Clean cloth

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KW-03Open the window and find the keepsOpen the sash and look along the frame edge for small metal plates with a screw or two - these are the keeps. The hooks or rollers on the sash engage into these when you turn the handle to lock. There are usually 3 to 5 along one side of a window. If your window has a child-safety restrictor fitted, leave it in place and work around it - don't remove it to make the adjustment easier.

KW-04Test each keep for playClose and lock the window, then check each keep in turn. A gap or draught at that point means the keep is set too far out and needs to pull the sash in tighter. A stiff handle or a sash that's hard to close square means a keep is set too far in and is over-tightening the seal.

KW-05Loosen the keep you're adjustingUnlock and open the window so you can reach the keep. Loosen its fixing screws with the Allen key or screwdriver by a couple of turns - just enough that the keep can slide, not so much it falls off. Don't remove the screws fully.

KW-06Shift the keep's positionSlide the keep about 1-2mm towards the room if you need a tighter seal, or slightly outward if the handle is too stiff to turn. Move it a small amount at a time - a couple of millimetres makes a noticeable difference to how tight the window pulls in.

KW-07Tighten and test that keepTighten the fixing screws back up, then close and lock the window. Check the handle turns smoothly and feel for a draught at that spot. If it's still not right, loosen again and nudge the keep a little further in the same direction.

KW-08Repeat for every keep along the frameWork your way along all the keeps on that side of the window, adjusting each one the same way. Aim to pull the sash in evenly rather than just tightening one end, or you'll twist the sash and make it harder to lock.

KW-09Lubricate the hinges and locking gearSpray a light silicone-based lubricant on the hinges, keeps, and the hooks or rollers on the sash edge. This keeps everything moving smoothly and stops the adjustment seizing up again with corrosion. Avoid oil-based lubricants, which can attract grit and gum up the mechanism.

1 each · Silicone-based lubricant spray

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KW-10Final check and tidy upOpen and close the window several times to check it locks smoothly and sits flush with no draught. Wipe off any excess lubricant with the cloth so it doesn't drip or mark the sill. Put your tools away.

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