We will install a comprehensive draught proofing system, hidden and rebated within your sash window so you get the benefits of modern technology, without damaging the style and elegance of your windows.
A brief rundown of the process is:
Remove and dispose of the staff bead.
Remove lower sash, cords and weights
Remove and dispose of parting bead
Remove top sash cords and weights
Scrape down pulley stiles
Carry out any specified repairs
Pack out or shoot in sashes to frame
Ensure meeting rails are aligned
Remove all old furniture
Repair where catches have been,
Re-hang top sash, balance weights
Install draught proofing into sashes
Fit new parting bead with draught proofing preloaded
Re-hang lower sash
Reinstall draught proofed or fit new staff bead
Fit new ironmongery/ locks (if necessary)
Below is the process of draught proofing a Box Sash Window in full:
First thing to note is whether there is anything that is obstructing the windows, so furniture is removed, curtains/blinds are taken down and the surrounding area is covered with dust sheets to avoid damage to furniture or flooring. If shutters or secondary glazing are installed which could obstruct the access to the staff bead then this will need to be removed too. Without clear access to the staff bead, then we cannot take the window apart to carry out the necessary works. You can see below the point of access required for safe removal.
The staff bead being removed internally means that, in almost all cases, sash windows are taken apart internally with no need for scaffolding.
As you can see above, we use a hammer and chisel to pry the staff bead away from the frame. This is done starting from the middle of the staff bead and slowly leavering top and bottom until free. This is intended to avoid snapping the staff bead if at all possible. It is however sometimes unavoidable as it could have already been spliced, brittle or a knot causing a weak point in the timber. Furthermore, the use of screws to install the staff bead makes it very difficult to avoid without prior knowledge of this.
Once the staff bead is removed on each side the sashes can be removed as you can see from the image below:
The cords now need to be cut. When cutting the cord, we need to hold it above where we are going to cut to avoid the weight and cord disappearing into the bottom of the box. Once the cord is cut, then the cord should be tied and carefully threaded back into the box with the knot holding the weight from the bottom of the box. This is done in case the weight is too large for the pocket. This means you are able to remove the weight from underneath rather than needing to take the frame apart for access.
In some scenarios, the pulley stile may need cutting to access the weight.
It is not uncommon to find that the windows are painted in. Using a chisel in the top left corner and top right corner (between the two sashes,) gently hammering and twisting the chisel, it is possible to ‘pop’ the paint. It is done from the sides rather than center to avoid breaking glass. Although the frames are generally very strong, bowing or twisting the sash can easily cause glass to break. Although we are all human, even sometimes it is unavoidable.
Once the bottom sash is free, it can be removed and placed safely out of the way. It is worth noting the choice of angle of the sash. This is done to avoid the sash from falling over breaking the glass. It is something we have to teach every new recruit, the importance of a good angle for the sash to ensure it does not fall over adding more work to our day.
Now we need to remove the parting bead. This is installed into a groove in the box frame. Using a hammer and chisel this is taken out of the groove.
Once both sides are removed, access is now available to remove the top sash. Similar to the bottom sash these can be heavily painted in place. From the left and right hand side at the bottom of the sash (usually where a ‘horn’ is present,) slowly pry the sash from the outer cheek. Again, being cautious of bowing the sash. Once the sash is free of the outer cheeks, it is best to ensure you support the underside of the sash in case the old cords are broken or missing. If paint is still gripping the top of the sash, use the hammer and chisel to separate the sash from the top of the frame using the same method of sticking to the top left and top right. The top sash should again be moved to the side clear of the frame.
Time to remove the weights. Using a chisel, we need to lever out the pocket carefully avoiding damaging the box frame. Once removed we are able to access the box to remove the weights. One at a time we need to cut the cord whilst handling the weight. Cutting close to the knot allows for as much access to the weight as possible. This will mean the weight can be removed using the bottom of the weight rather than trying to pull it out of the box from the top later potentially getting stuck or damaging the pulley stile. Once the weights are removed they are placed on to the pockets to ensure they do not damage the flooring. For ease of remembering which weight belongs to which windows, left weight is for ‘outside’/top sash left, right weight is for ‘outside’/top sash right, middle left weight is for ‘inside’/bottom sash left and middle right weight is for ‘inside’/bottom sash right.
The sashes and weights are not weighed to ensure they are correctly balanced. If necessary, additional weight is cut and added.
The cords are then installed into the box. Feeding the cord into the inside left pulley and down into the box, the cord is pulled down through the pocket. The cord is then pulled through and fed through the inside right pulley. Repeating the process across to the outside left pulley and the outside right pulley leaving some length of cord coming through the right hand pocket. This should leave a cross of the cords as seen below.
The bottom sash is installed using the same process as the top sash, resting the bottom sash on the sill for ease of installation and the pins removed at the pulley once the cord is attached. Finally the staff bead is replaced. The staff bead is either routered (if in tact) and installed with a flat runner and brush to keep original (wherever possible.) Alternatively, a new preloaded staff bead is installed. Caulk is used to seal in the staff bead to tidy in the joints.