SASH CORDS SPIRAL BALANCES
Sash cords spiral balances are mechanisms which allow your windows to stay open properly. Both are based on a counterweight system, sash cords by weights, spiral balances by spring tension.
WHAT ARE SASH CORDS AND SPIRAL BALANCES
Sash cords are the ropes supporting timber sash windows with weights. Replacing involves the simple removal of the outer stop bead before accessing the box cover behind it to access the weights inside.
Spiral balances are found in both timber and aluminium windows. In timber windows, they are the plastic pipe where normally you would find the cords, and unless painted, are normally black.
Whereas sash cords always require taking out the associated sash spiral balances are generally able to be installed without removing the sash.
In timber windows, the exception is where new 14mm balances are being installed, and the previous balances were thinner, as in the older styles. Some spirals, particularly in blocks of flats are the Gainsborough Unique 11mm spiral balances, which tend not to last very well. When upgrading to Whitco 14mm balances, the sash will need to be pulled out and routed to 15mm.
These are very difficult, and methods are described here.
Timber Window Repairs