Techniques > Systems
> Windows > Conservation
|Sash cord fastener patented by Margaret Jane Hufman, Dec.
|Cotton sash cord.
Gain access to the sash chord
To gain access to a window's sash cord, remove the inside
window stop from both sides of the sash, and if the upper
sash needs attention, the parting stops separating the
two sashes must also be removed. Carefully pry the stops
away from the jambs, using a wide putty knife.
Lift Out the Sash
Lift the sash clear of the stool and swing it out. With
the sash free from the window, remove the sash cord from
the keyed slot in its side.
New Sash Cord
Thread the new sash cord over the pulley and down into
the sash-weight cavity until it appears at the access
panel. Tie the new sash cord to the sash weight, and then
put the weight back into the cavity. Knot the other end
of the sash cord at a point that will permit the weight
to hang 3 inches above the sill when the sash is fully
raised. Reinstall the sash and nail the stops. Touch up
with putty and paint as necessary.
Sash cords should be given attention at the same time as any
extensive repairs and replaced if necessary. If a considerable
amount of glass has been replaced it will be necessary to adjust
the weights. Traditionally, the combined downward pull of the
weights serving the top sash should be slightly more than the
sash itself, including glass, so that it has a tendency to close
easily. The weights serving the lower sash should be slightly
lighter than the sash itself for the same reason.
Wrightson, David. The Conservation and Renewal of Timber
Windows, Public Information Leaflet, Cathedral
Communications, Wiltshire, England [PDF file]
Replacing a Sash Cord
Even if the other cords appear sound, it is usually sensible
to replace them all. This can be done as follows:
- The lower sash is first removed by carefully taking off
the staff beads, which will free the sash.
- Disconnect the sash cords from the sash and tie a knot
in the cord to prevent the sash weight dropping to the bottom
of the box.
- Take out the parting beads and the upper sash will now
be free to be removed, restraining the sash cords as with
the lower sash.
- Take out the pockets, which are loose pieces of wood normally
held in place by the parting beads; by moving the wagtail
from side to side and letting down the cords it should be
possible to find the weights in the box.
- If any of the glass has been changed since the windows
were hung, the sashes should be weighed at this stage.
- A new length of cord (waxed sashcord is best) is weighted
with a nail, threaded through a pulley and allowed to drop
until it can be reached through the pocket.
- The weight should be tied to it with a secure knot (bowline
or similar), with make-weights added as necessary to balance
the weight of the sash, and replaced in the box.
- When all the cords have been inserted in this way, the
free end of a cord is then nailed with three flat headed
nails into the groove in the side of the upper sash, adjusting
the lengths of the cords so that the weights do not quite
touch the bottom of the box when the sash is at its highest
- When the upper sash has been hung the pockets can be
put back and the parting bead replaced (or renewed if damaged).
- The lower sash can then be rehung, finally replacing (or
renewing if damaged) the staff bead, ensuring a firm, but
not tight, fit.
Guide to the Repair of Sash Windows [PDF file],
Building and Maintenance Guides, Planning Department of
the London Borough of Islington and Roger Mears Architects