What is a window jamb liner, and can it help an old window pass a lead inspection?

A jamb liner is window weatherstripping: metal strips that line the sides of the window frame (the jambs). The sash rides on the metal instead of rubbing painted wood, and the strips seal out drafts.

That matters for lead because rubbing is one of the main reasons old windows fail inspection. When a sash grinds against a lead-painted jamb, every opening makes lead dust. Covering the jamb is called enclosure, one of the approved ways to deal with lead hazards, along with paint removal, sealing intact paint, and replacing parts.

Types of jamb liners for historic windows

• Spring bronze: a thin, springy bronze strip nailed into the jamb. See spring bronze weatherstripping.
• Interlocking jamb strips: metal strips in the jamb that engage a groove in the sash for the tightest seal.

When a jamb liner makes sense

• The jamb paint is rubbing and you don't want to strip the whole frame.
• The window gets used often, like in a rental.
• You want a tighter, smoother-running sash at the same time.

Things to know

• Remove failing paint or seal intact paint before the metal goes on.
• Enclosure covers the lead rather than removing it, so check it over time.
• Tune the sash to the liner so the stops and parting strips don't rub.

See all of our weatherstripping for historic doors and windows, or call Classic Door at (401) 266-4475 to have us install jamb liners as part of a lead-safe window restoration.