Stiff sash lock on a stone-built terraced house
Common on stone-built terraced houses across Sheffield — the timber door has moved seasonally and the mortice case has bound against the keep. We often see this coupled with mortice deadlock wear on stone-built terraces. The fix is either service (lubricate and adjust) or replace with a BS3621 equivalent if the existing lock is pre-standard.
Our approach Service first if the mechanism is sound; BS3621 upgrade if the existing lock is sub-standard or worn beyond service.