Once a Snug sash renovation and draught-proofing job are done, the windows will slide smoothly and easily using only one hand.
Added brushes reduce the friction and we usually install new pulleys which run smoothly.
The weights that the sashes were originally paired with are usually only close to the correct weight. We accurately weigh the windows and the weights and add additional lead weights so they are balanced perfectly. This results in a perfectly smoothly running window.