Dear Old House Owner:
Many old houses built before 1950 still have the original sash cord windows. If they are properly maintained these windows move easily; however, in many houses the windows no longer function properly. In addition, they are extremely difficult to insulate. The windows are not tight to the jambs, and the pockets where the weights sit create large voids of uninsulated wall on either side of the windows, as shown below.

.empty window weight pocket

These sash cord pockets are commonly three inches wide and extend the length of the wall.  In a typical house, having 8 sash cord windows means that the total uninsulated space of the sashcord pockets is equal to an uninsulated space the size of a door!  

As energy efficiency and insulation have become more important and popular old windows have become a focus area for many homeowners.  An oft-promoted solution to the problem of old, unopenable, and leaky wood windows is vinyl replacement windows.   There are several significant problems with this approach though. Vinyl windows do not look the same as wood, so they often do not match original trim or shutters.

Most of the time when vinyl windows are installed the pulleys and weights are left in place, which means that the weight pockets are never insulated. This means that even though the new window is tighter and better insulated, the sash cord pocket space is still uninsulated.

What Old House Carpentry LLC offers is a window retrofit that preserves the original wood windows while  solving the problems of insulation and ease of use. We do this by milling the sides of the original wood windows and fitting them with vinyl Jambliners. In addition we insulate the old sash cord pockets, add weather stripping to the top and bottom of the  windows, and add exterior storm windows if they are not already present.

This window retrofit provide the following benefits:

  • The windows slide easily and stay open in any position.
  • They allow the sash to tilt for easy cleaning and maintenance.
  • They are virtually invisible from the outside after installation.
  • The retrofitted windows are significantly more airtight.
  • When they wear out or break, Jambliners are much less expensive to replace than full  windows.

Leave a Reply

Your email address will not be published. Required fields are marked *