Sash windows were very popular from Georgian to Edwardian times and are still made today, although more often to replace existing ones than to go into new houses. Although no other window style looks right in these houses, all to often they are replaced with UPVc imitations which are better insulated and cheaper, even though they look awful.
Repairing and Refurbishing SASH Windows
Wooden sash windows can be repaired and refurbished and now can be double glazed, although no one would pretend that the process is cheap, and the insulation properties are still less than those of a modern non-sash window.
The problems with draughts and sticking windows often put paid to sash windows, at least in the owners’ eyes, but regular maintenance can help a great deal. And if a window is impossible to open, it’s either stuck with paint or it’s a problem with the weights and cords, which are in the ‘boxes’ on either side of the window.
If you look at a sash window you will see that the two sides of the frame, where it is fixed to the wall, are very thick. This is because they are hollow and cords attached to the sides of both windows go over pulleys and into the box where weights counterbalance the weight of each window panel (or ‘sash’) itself.
Sash windows are much more complex than ordinary casement windows but the dismantling and reassembly procedures are reasonably simple if taken step by step. The outer sash is usually the top one so you may have to raise it and nail a block of wood in place to hold it there. Don’t be tempted to prop it with a piece of timber as it can easily be knocked while you are working and the window could smash if it drops or falls out.
Taking Each Sash Out
First remove the beading that prevents the inner (usually lower) of the two sashes from falling out (the ‘staff’ bead) then this one should be free to come out. Unless the cords are broken it will not come completely free, so you will have to have someone support the sash while the cords are removed from the upper side edges of the sash. They are usually nailed or stapled in.
Once that sash is completely removed and out of the way, remove the moulding (known as a parting bead) which separates the track for the inner and outer sashes on both sides and remove the top sash in the same way. Then look for the ‘pockets’, little windows low down in the boxes with wooden covers. Remove these covers and you should be able to remove the weights through the pockets.
Replacing the Cords
Now is the time to check that the pulleys run smoothly and freely, and replace or fix them if they do not. Assuming you are replacing the cords, measure up new ones, using the old ones as a guide. If the sashes are missing, the length should be enough to allow the weight to be at the top of the box when the window is lowered and just above the bottom of the box when it is up.
To get the new sash cords in place, tie a small weight to a piece of string and pass it over the pulley and down to the bottom of the box. A strip of lead wrapped around the string is ideal for this; the technical name for it is a ‘mouse’. Then fish the mouse out through the pocket, tie the sash cord to the string and pull it all through, taking care not to allow the end of the cord past the pulley at the top. Reaffix the weights to the bottom of the cord using a non-slip ‘figure-of-eight’ knot.
Look Out for the Wagtail
Note that there will be a slim batten (called a ‘wagtail’) separating the two channels in each box and make sure that each cord is the correct side of the wagtail. You don’t need to remove the wagtail to access the weights and cords, you should be able to push it aside. It is not very strong or firm, it exists purely to keep the two weights apart so that they don’t clunk when sashes are raised or lowered. You should always do the outer window first.
Put the lids back on the pockets and, using your helper once more, lift up the outer sash, reattached the cords and put it in place, again nailing your block in place if necessary. Replace the parting bead and repeat the procedure for the inner sash then replace the staff bead, in both cases replacing them if they were damaged when they were removed. Then step back and admire your handiwork.
Repair and Paint the Wood
If you do have to do this procedure it makes sense to fix any problematic woodwork and sand and paint the whole frame and sashes. Check out our article in this section to find out what to do and what to avoid. Make sure they are both fully dry before putting the sashes back in though, or they will get stuck together. This may mean leaving the sashes out for a day or two, particularly in the winter, so make sure you have a suitable size of wood to put in place temporarily if necessary.
Redoing the paint should make the sashes slide better, as long as you don’t put down too much, and should improve draughtproofing. Also take the opportunity to fit draught excluders specially made for sash windows. These have improved dramatically over the last few years and again there is an article in this section that covers draughtproofing sash windows.