Save America's Windows

A common condition is when there is too large of a gap between the side edges of the sash and the jambs, which allows the sash to move sideways, back and forth, between the jambs. There should be a little gap all along the edge, perhaps something just over 1/16", but if the gap is more than 1/8" it may be too much.

Assess Conditions
First determine the cause of the gap. Here are some possibilities:
-- Edges of the sash are worn, or maybe even the surface of the sash is worn
-- One, or both, of the joints where the jamb meets the sill or the frame header have failed, letting the jambs spread, leaving a greater space for the sash
-- The sash is a replacement and not as wide as the original
-- The window originally had weatherstrip between the sash and the jamb that took up the space, but it is gone, leaving a gap

Because the cause of the gap in your case may vary, there are different approaches to consider.

If the sill or header joints have failed consider if you will repair them and bring the jambs closer together, or if you will accept the current position of the jambs.

If the gap is small and spring bronze weatherstrip will be added, the leaf of the spring may take up the space. If ribbed metal weatherstrip will be added a continuous shim might be placed between the weatherstrip and the jamb.

If the edges of the sash are worn they can be rebuilt by gluing a strip of wood onto one or both edges. Match the species and quality of the wood in the sash stiles and for longest durability match the growth ring orientation.

Let me know which approach you will take and I'll provide more details if you need them.

John

I have the problem you describe -- excessive play between jamb and sash, but I don't think it's due to any of the causes you describe. The jamb joints are solid. This is definitely an original sash. Perhaps it's worn, but it didn't seem overly so when I looked at it.

I took the casing off and is seems that this weight pocket is narrower than others I've been working on in my house (ca 1910). Everything is built by hand, of course, so I'm thinking it may have been built wrong from the beginning, but given the quality of craftsmanship elsewhere, that seems unlikely. Perhaps this is a replacement sash after all, but if so, it's from the same period as everything else.

There's too much play now for bronze weatherstripping to be very effective. I have thoughts of placing shims on both jambs, but I'll have to do it in multiple pieces to avoid closing the weight pocket access doors permanently. If I take this route, what wood should I be using? I don't want to use the soft pine garbage that's being sold now. I usually use poplar to replace the pine. Does that make sense and would it last as long as the rest of the assembly? If I do put in shims, should I carry them from the parting strip all the way under the side stops? Should I take a different approach?

I know that's a lot of questions; any information would be greatly appreciated

Gerry

Gerry, welcome to the Forum!

Rolled Spring Bronze and V Spring Bronze can take up to 1/4" of sideways play in the sash.

When I want to take up play I usually glue strips of wood to the side edges of the sash. This leaves all the details and functions of the jamb in place. After gluing the strips in place I cut out the plough groove and hole for the sash cord, if necessary.