Window and Screen Repair Standard

Purpose

Two things go wrong on a window call and neither one is the repair itself. The tech breaks the glass he came to save, usually while pulling a sash whose balance was still wound. Or he restores the operation of a bedroom window and hands it back opening less far than it did, which nobody notices until the night somebody needs it.

This procedure guarantees the opening is measured before anything moves, the balance is released before a sash leaves the jamb, and the sash is proved to hold its own weight before the tech leaves.

Scope

Covers single and double-hung, slider, casement and awning windows in dwellings and small commercial spaces: screen rescreen and frame repair, sash locks and keepers, balances and sash cord, crank operators and rollers, track and weep-hole clearing, and re-glazing single-pane putty sash.

Does not cover a sealed insulated glass unit or any fogged unit, which is a glass shop; glass in a hazardous location, which needs listed safety glazing; whole-window replacement; rot in the sill or jamb, which belongs to the exterior trim procedure; or screen and storm doors.

Roles and responsibilities

Procedure

1. Measure the operable opening and write it down before anything moves. For any sleeping room, open the sash fully and measure clear width and clear height, then compute the net clear opening in square feet. Acceptance: pre-work clear width, clear height and net clear opening recorded on the ticket for every sleeping-room window. IRC Section R310, in the edition your jurisdiction has adopted, sets what new work has to reach: 5.7 sq ft of net clear opening, 5.0 sq ft at a grade-floor opening, with at least 24 in of clear height and at least 20 in of clear width, and meeting both of those minimums together still leaves you well under the area figure. A repair does not bring an existing opening up to those numbers, so the shop rule is that you do not hand it back smaller than you found it, and the ticket says where it sits against them. What wrong looks like: a stop added to kill a rattle, quietly costing 3 in of clear height. Stop rule: any repair that would reduce the opening goes to the lead first. Hazard: none physical here, but keep small children out of the room while the sash is open.

2. Deal with broken glass before you touch hardware, and decide whether the pane is yours at all. Tape a cracked pane across the crack on both faces and immobilize the sash. Acceptance: no loose shard anywhere in the opening, the sash locked or blocked so it cannot travel, and the glass location classified. Stop rule: glass in a door, glass in a panel whose nearest vertical edge falls within a 24 in arc of a closed door's edge where its bottom exposed edge also sits under 60 in above the floor, glass in a tub or shower enclosure, or glass otherwise in a hazardous location under IRC Section R308 in your adopted edition, must be listed safety glazing, and that pane goes to a glass shop rather than being cut on site. What wrong looks like: sweeping fragments up and calling the sash clear while a wedge stays bedded in the putty. Hazard: glass under bedding tension springs when the last point is relieved, so cut-resistant gloves and eye protection on, work from the side rather than face-on, and pick shards with pliers.

3. Release the balance before any sash leaves the jamb. Block-and-tackle, spiral and coil balances are all wound springs holding the sash's weight. Acceptance: the sash supported by hand or a prop, the balance shoe locked or the take-out clip engaged per the manufacturer's method, and a second person confirming aloud that the balance is disengaged before the sash tilts. What wrong looks like: a spiral balance tube spinning free the moment the sash tips, unwinding several turns in under a second. Stop rule: a balance that will not lock stays in the jamb and the sash is not removed; the visit becomes a parts visit. Hazard: a released spiral balance drives its tip toward the hand and face, so keep your face out of the tube line, never cut a cord or tube under tension, and unwind with the manufacturer's tool rather than a screwdriver.

4. Check the age of the paint and putty before you scrape, sand or heat anything. Acceptance: pre-1978 construction identified and the paint disturbance procedure opened, or the building recorded as post-1978. Stop rule: pre-1978 painted sash and glazing putty route to that procedure, which owns containment and the certified-renovator question, and under 40 CFR 745.85 open-flame burning and heat guns above 1100 degrees F are prohibited practices on those surfaces. What wrong looks like: softening old putty with a heat gun at full setting on a 1940s sash. Hazard: lead reaches the tech by inhalation of dust and fume and by ingestion off the hands, so hands get washed before eating or driving, and an accidental disturbance means stop and leave the debris in place.

5. Rescreen on a bench, and check the frame before you spend spline on it. Acceptance: frame diagonals within 1/8 in of each other, spline groove unbroken on all four sides, corner keys tight, and finished mesh flat with no visible wave and no permanent dish after a light finger press. What wrong looks like: mesh pulled so tight it bows the frame into an hourglass, which pulls the corners apart within a season. Stop rule: a bowed frame, split groove or broken corner keys means a new frame. Hazard: the spline roller skips off the groove into the hand holding the frame, so clamp the frame to the bench, and trim excess mesh away from your body with a fresh blade, since a dull one needs force and jumps.

6. Clean tracks, replace rollers or the operator, adjust the keeper, then prove the weeps drain. Acceptance: the sash travels its full range with one hand and no binding, the lock throws fully and pulls the sash to the weatherstrip without anyone lifting it to make it engage, and water poured into the sill track exits outside within about a minute. What wrong looks like: a lock that only catches when the sash is pushed up, which is a keeper adjustment sold as a working lock. Stop rule: a crank operator with no available gearbox parts is a unit replacement decision for the lead, not a field rebuild. Hazard: fingers sit in the closing path of a sash that can drop, so keep the hand on the stile, and where the sash is out at a second-floor opening, guard the opening before you turn your back on it.

7. Re-glaze single-pane sash bedded, pointed and tooled. Acceptance: glazing points at least two per side and spaced no more than about 8 in, the pane bedded with no dry gap, face putty struck to the interior sight line so none shows on the inside face, and the pane holding without rattle. What wrong looks like: points driven in with no bedding compound, which telegraphs as a rattle in wind and a leak at the bottom rail. Stop rule: a sash whose rabbet has soft rot does not get re-glazed, because the putty has nothing to key into; it goes to the lead. Hazard: driving points slips the tool along the glass into the hand, so push points with a dedicated glazing tool bearing on the pane, gloves on, eyes protected against a pane that lets go.

8. Re-hang, prove the sash holds its own weight, re-measure the opening, and hand over. Acceptance: balances re-engaged and taking load, the sash released at half travel holding with no more than about 1/2 in of drop in 60 seconds, which is a shop gate rather than a published one, lock engaging as at step 6, screen back in, and the net clear opening re-measured to equal or exceed the step 1 figure. What wrong looks like: a sash that stays up when pushed hard against the jamb and slides shut once the friction relaxes. Stop rule: any drop beyond the gate, or an opening smaller than step 1, fails the visit and the window is left operable and reported rather than declared done. Hazard: this step puts the sash's weight back on a spring you disturbed, and a double-hung sash falls like a guillotine, so release with both hands on the stiles, nothing under the bottom rail, customer out of the room.

The record this produces

Window type and location, whether the room is a sleeping room, pre-work clear width, clear height and net clear opening, glass condition and any hazardous-location referral, balance type and whether it locked, parts replaced, the drain test result, the half-travel hold result, and the post-work net clear opening beside the pre-work one.

The office reads the two opening figures side by side when a landlord or an inspector asks whether the shop made an egress window smaller. The next tech reads the balance type so the right part is on the truck for the return visit.

Worked pass: 1962 double-hung, second-floor bedroom, stuck sash and torn screen

Complaint: bedroom window hard to open, screen torn, and the customer wants the lock to work again.

Step 1: sash opened fully, clear width 28 in, clear height 24 in. 28 times 24 is 672 sq in, and 672 divided by 144 is 4.67 sq ft of net clear opening. Recorded as the pre-work baseline, and recorded as short of R310 on area: 4.67 sq ft is under the 5.7 sq ft figure and under the 5.0 sq ft grade-floor one, while the 24 in clear height sits exactly on its minimum and the 28 in width clears the 20 in one. The house predates the adopted edition and the repair does not bring it into compliance, so the shortfall goes on the ticket as found, and the binding rule for this visit is that the post-work figure must not fall below 4.67 sq ft.

Step 2: no broken glass, one pane loose in dry putty at the lower sash. Nothing in a hazardous location under R308, so no glass-shop referral. Step 4: house is 1962, so the paint disturbance procedure opened before any scraping, and no heat gun came out of the truck.

Step 3 FAILED. The left spiral balance locked on its clip. The right one would not: the tube spun free under light hand pressure, so it could not be confirmed disengaged. Under the step's stop rule the sash stayed in the jamb and was not removed. That killed the re-glazing, which needs the sash on a bench, and the tech said so on site rather than pulling it anyway.

Scope split on a call to the office: screen and lock work went ahead, and the right balance plus the lower-sash re-glazing became a parts visit, with balance type and length recorded off the left unit so the right one could be matched. About 20 minutes added to a two-hour booking.

Step 5: screen frame diagonals measured 1/16 in apart, groove intact, corner keys tight, so it was rescreened rather than replaced, finishing flat with no wave and no dish.

Step 6: tracks cleaned, keeper moved 1/16 in toward the sill. The lock now throws fully with the sash resting closed, no lifting. Water poured into the sill track drained outside in about 30 seconds.

Step 8: nothing had been removed, so there was no balance to re-engage; the half-travel hold was still run and the sash held with no visible drop over 60 seconds. Opening re-measured at 28 in by 24 in, 4.67 sq ft, equal to the step 1 figure. Both figures went on the ticket.

References

• IRC Sections R310 (emergency escape and rescue openings) and R308 (hazardous locations and safety glazing), in the edition your jurisdiction has adopted, which bind new work and reach a repair through the permit and the shop's do-not-make-it-worse rule
• 40 CFR 745.85, work practice standards for renovation of pre-1978 target housing, including the prohibited practices on painted surfaces
• The balance, operator and screen frame manufacturer's instructions for take-out method, tension release and spline size for the units in front of you
• See related: Pre-1978 Paint Disturbance Stop and Assess; Screen Rescreen vs Replace vs New Frame; Interior Door Adjustment and Replacement