The term window jammer is commonly used for surface-mounted security fittings on modern casement windows. Many such products are not designed for vertically sliding timber sashes. Check the exact application and clearances before buying.
Are sash window jammers the right choice?
Our guidance focuses on traditional timber sliding sash and case windows, rather than assuming every modern window security fitting will work on a heritage sash.
What is a window jammer?
A window jammer is usually a surface-mounted fitting designed to impede opening. Many products marketed this way are intended for outward-opening uPVC or timber casement windows.
Compatibility with sliding sash windows
A vertically sliding sash needs unobstructed travel and sufficient fixing material. A generic jammer may foul the movement, damage the frame or fail to secure the intended part.
Alternatives for traditional sashes
Purpose-made keyed sash locks, stops and compatible restrictors are often more appropriate. The correct option depends on the window design and its use.
Safety considerations
Never obstruct a designated escape opening or rely on an untested device as a child-safety measure. Check the manufacturer’s fitting instructions and suitability.
Related sash window lock guides
Related sash and case window services
Explore our sash and case window repairs in Stirling, window restoration, sash cord replacement and draught proofing.
Frequently asked questions
Can I fit new locks to old sash windows?
Often, provided the timber is sound and the hardware suits the sash design. Check alignment, clearances and any heritage constraints first.
Will a replacement fastener make my sash window secure?
A meeting-rail fastener mainly holds the sashes together. Additional security may require appropriate locking hardware and repairs to the window itself.
Do you supply and fit sash window locks?
Contact us to discuss inspection, repairs and suitable replacement fittings for timber sash and case windows. Online product sales are not yet available.
Need advice about a sash window lock? Contact The Sash & Case Window Company for an assessment or quotation.
