In this regular series, Mike Derham, Managing Director of Mighton Products, sash window hardware specialist, provides a step-by-step guide to routine sash window maintenance.

Double hung sash windows are common in older properties and most installers will come across them. Whether in a renovation project or wholesale window replacement, removing them safely, with the least possible impact to the window and its frame is crucial. The correct approach can save a lot of time and effort making good unnecessary damage.

Step one – Remove staff bead

Working from the inside, start by removing the outer staff bead. Usually nailed into place and coated with many layers of old paint, the staff bead stops the bottom sash swinging from its vertical position. Resist the temptation to use a chisel to break the seal. Instead take a wooden block, line it up with the join (image 1), and tap gently but firmly until the paint breaks. Doing this along the whole length of the bead should mean it’s reusable.

                                                                                              Image 1

Step two – Remove bottom sash

Now the bottom sash can be moved out from the frame, enabling access to the cord. To remove the bottom sash completely, the cord that carries the sash needs to be detached. Various ways of attaching the cord to the sash are in use; Mighton’s Grabba is increasingly common (image 2). Because, in most cases, using the Grabba cords don’t have to be pinned into place with a hammer and nails – an all too common cause of broken windows. If a Grabba is in use, simply pull the cord down and out of the teeth and unthread it, keeping hold of the cord at all times. If pinned, pull the cord away from the frame with a gentle, constant pressure until the cord becomes free of the frame.

                                                                                                   Image 2

It’s especially important to keep hold of the cord if your plan is to reuse it, as letting go will see the cord, pulled by the sash weights, disappear into the weight cavity. Time spent delving around inside the cavity, trying to find the cord is avoidable by tying a knot big enough to prevent it passing over the pulley (image 3). Repeat the process on the other side of the bottom sash window and set the window safely to one side.

Image 3

Step three

The first two steps apply when removing the top sash window too, only this time instead of a staff bead, you need to remove a parting bead before taking the top sash out. Parting beads keep the top and bottom sashes apart and sit in a groove running the length of the pulley stile. You may need to use a little more force than with the staff bead, but as before, use gentle persuasion not brute force (image 4) to limit damage to the frame.

                                                                                                Image 4

Step four

Now move the remaining top sash away from the frame (image 5) and repeat step two, taking care not to lose the sash cords into the weight cavity. When complete, full access to the frame is available.

Image 5

Not rocket science

Taking care how you remove a sash window saves time and money. Although not hard when you know how, the effects of a poorly renovated or replaced window will have a long lasting effect on the operation of the window, and it means costly callbacks.

Next month we’ll look at one of the most important aspects of a sash window – the weights. The step-by-step guide will show you how to professionally remove and replace sash weights, giving your customer a smoothly operating window, and you a great reputation.

Want more information or advice? Email Mike Derham at mike@mighton.co.uk.