Repairing Double-Hung Window Sash Weights And Cords/Chains

Technical Procedures Disclaimer

Prior to inclusion in GSA’s library of procedures, documents are reviewed by one or more qualified preservation specialists for general consistency with the Secretary of Interior Standards for rehabilitating historic buildings as understood at the time the procedure is added to the library. All specifications require project-specific editing and professional judgement regarding the applicability of a procedure to a particular building, project or location. References to products and suppliers are to serve as a general guideline and do not constitute a federal endorsement or determination that a product or method is the best or most current alternative, remains available, or is compliant with current environmental regulations and safety standards. The library of procedures is intended to serve as a resource, not a substitute, for specification development by a qualified preservation professional.

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We’ve reviewed these procedures for general consistency with federal standards for rehabilitating historic buildings and provide them only as a reference. Specifications should only be applied under the guidance of a qualified preservation professional who can assess the applicability of a procedure to a particular building, project or location. References to products and suppliers serve as general guidelines and do not constitute a federal endorsement nor a determination that a product or method is the best alternative or compliant with current environmental regulations and safety standards.

PART 1---GENERAL

1.01 SUMMARY

  1. This procedure includes guidance on inspecting and correcting a faulty counter-balancing system. This problem may be caused by a missing sash cord/chain, an unattached or missing sash weight, a pulley in poor condition, or as a result of the replacement of the glass installed in the frame with a heavier or lighter material.
  2. When a window sash will not stay open and slides back down to the closed position or when a window is difficult to slide, a faulty counterbalance system is often the cause.
  3. See "General Project Guidelines" for general project guidelines to be reviewed along with this procedure. These guidelines cover the following sections:
    1. Safety Precautions
    2. Historic Structures Precautions
    3. Submittals
    4. Quality Assurance
    5. Delivery, Storage and Handling
    6. Project/Site Conditions
    7. Sequencing and Scheduling
    8. General Protection (Surface and Surrounding)
      These guidelines should be reviewed prior to performing this procedure and should be followed, when applicable, along with recommendations from the Regional Historic Preservation Officer (RHPO).

1.02 DEFINITIONS

  1. The counterbalance system in a double hung window is usually divided for the upper and lower sash. Each system contains sash weights, sash weight pulleys, sash cord/chain, sash cord slot located in the stiles of both of the sashes, and the weight access pocket in the jamb (Not in all double hung windows).

2.03 SYSTEM DESCRIPTION

  1. A window sash in proper working order is freely sliding, has balancing and moving apparatus in working order, and has operable sash lock(s) to deter air infiltration.

PART 2---PRODUCTS

2.01 MANUFACTURERS

  1. Architectural Iron Co.
    1. For sash weights
  2. Barry Supply Company
    1. Pulleys, sash weights, old hardware
  3. Blaine Window Hardware, Inc.
    1. Pulleys
  4. Casting Unlimited
    1. Manufactures sash weights with your pattern or sample
  5. Hern Iron Works
    1. Sash weights; has patterns for most sizes, requires a minimum order
  6. The Woodstone Company
    1. Sash manufacturer; will sell pulleys

2.02 MATERIALS

  1. Sash cord/chain to replace existing cord/chain.
  2. Salvage sash weights if original ones are missing.
  3. 1" PVC pipe and sand or lead shot to fabricate replacement sash weight if necessary.
  4. Pulley
  5. Oil, motorcycle-chain lube or powdered graphite to lubricate pulley
  6. Baking Soda is needed to remove paint from pulley (see 3.02 C. 1. b. below)

2.03 EQUIPMENT

  1. Stiff putty knife
  2. Small pry bar
  3. Wide chisel
  4. Wood screws
  5. A "Pinpoint Oiler" which could be an aerosol can with an extension tube or a disposable glue syringe
  6. A buffing machine
  7. See also "Unsticking a Wood Double -hung Window Sash".

PART 3---EXECUTION

3.01 EXAMINATION

  1. Check for the presence of a sash cord or chain. If it is present and in proper working order, proceed to Section 3.02 B. If the old sash cord is missing, replace it Replace sash cord with cord; sash chain with chain. In many cases, you cannot switch between the two as the hardware (including the pulleys) may not be compatible with a change from chord to chain, or vise versa.

3.02 ERECTION, INSTALLATION, APPLICATION

  1. To replace a sash cord/chain:
    1. Remove the sash as outlined in 08610-03-R, "Unsticking A Wood Double-hung Window Sash".
    2. Remove cord from slot in sash and ease the knot of the cord up towards the pulley, located in the jamb, until it stops and is held in place by the pulley.
    3. Locate weight access door in the jamb and carefully remove it. Remove weight from pocket and untie it. If jamb does not have access door, or if access door has been covered with weatherstripping, the window trim will have to be removed to access the weight pocket.
    4. Remove old sash cord/chain and cut a new cord/chain to match its length.
    5. Secure one end of new sash cord/chain to window and thread other end over pulley into weight pocket. Attach cord/chain to weight and replace in pocket. Replace access door and/or trim.
    6. Pull cord/chain from other end until weight just touches pulley and temporarily secure the cord/chain and pulley in place with a nail (threaded through a link of the chain or the weave of the sash cord) across the pulley hole.
    7. Secure other end of cord/chain to slot in sash with 2 wood screws. Remove the nail which is temporarily holding the chain or cord keeping the weight in the up position.
    8. Repeat procedure on other side of sash. Reinstall sash and stops.
    9. If sash cord/chain is missing altogether, pull weight up to pulley and temporarily secure it as in (6) above. With the window in the closed position measure enough cord/chain so that the end can be screwed into the sash slot. Cut cord/chain and continue as in (7) and (8) above.
  2. Check if sash weight is unattached or missing:
    1. Secure the sash in an open position.
    2. Locate and remove the weight access panel in the jamb.
    3. If weight is present but unattached, retrieve it and the end of the sash cord out of pocket and reattach. Return them to pocket and replace access door.
    4. If weight is missing or not retrievable, it must be replaced. Salvage is the first choice for replacement. If a salvage weight is unavailable or new sash weights cannot be easily purchased, a sash weight can be fashioned out of a 1-1/2" diameter PVC pipe with the end sealed and filled with sand or lead shot to the proper weight.
    5. To determine size of sash weights:
      1. Weigh the sash and divide by two
        -OR-
      2. Use the following formula: [(sq.ft. glass)+ (height {ft.} x width {ft} x depth {in})]
  3. Check condition of pulley. Paint and dust build-up may be causing the pulley not to function properly.
    1. If pulley appears to be free from paint or dust build-up, re-lubricate the pulley using a pinpoint oiler to lubricate the wheel-and-axle surface.
      -OR-
    2. Recondition the pulley:
      1. Remove pulley from window frame. It may be attached by in one of two ways: two obvious countersunk wood screws or a friction fit. Care must be exercised when removing a friction fit pulley because it is anchored in place with hidden spurs. Wedging a screwdriver between the wheel and case will damage the pulley.
      2. Paint can be removed from a pulley by using the following method:
    3. Place the hardware in a large metal cooking pot with a solution of 4 quarts of water and 4 tablespoons of baking soda.
    4. Place on a kitchen stove over a low-to-medium heat to simmer (not boil) for 30 minutes.
    5. Remove the pieces while still hot, using tongs. Place on paper towels, then carefully brush with a stiff nylon bristle brush to remove all paint. Dispose of debris using proper waste procedures.
    6. If some paint will not come off, place back in the pot for another 30 minutes and try again.
    7. If there is no rush, the hardware may instead be placed overnight in a residential-grade "Crock-pot" slow-cooker, and they will be ready for cleanup the next morning.
    8. Be aware that the cooking pots utilized for this operation should never again be used for food or other consumables.
      1. When paint and dirt are removed, re-lubricate the wheel-and-axle surface (as in 3.02 C. 1. above) and reinstall.