Window Glass & Sash Repair on San Juan Island

Almost every house I go into out here has at least one hazy window. Not dirty — hazy on the inside of the glass where nobody can reach it, with a tide mark low on the pane and sometimes a faint white bloom in the corners. That is a failed insulated glass unit, and it is probably the single most common unaddressed defect in island housing stock. This page is about that, about broken and cracked panes, and about the moving parts of a window: sash cords, balances, casement operators, and the weatherstripping on the sash itself.

It helps to know what is actually failing. A double-pane window is two sheets of glass held apart by a metal or composite spacer bar, sealed at the edges, with the cavity filled with air or argon. The spacer is packed with a desiccant — usually silica pellets, which have an enormous internal surface area and can hold a great deal of water vapor — whose job is to keep the cavity bone dry so the inner glass surfaces never reach dew point. The edge seal is what keeps the outside air out. When that seal starts to leak, the desiccant slowly loads up with moisture, and the day it saturates, the cavity starts condensing. That is the haze. The unit does not fog because it got dirty. It fogs because it has already been leaking for years.

What tires the seal out is daily flexing. The sun heats the trapped gas, the cavity pressure rises and the glass bows outward, then it cools overnight and pulls back in. Do that a few thousand times and the sealant at the edge works loose. Glaziers call it solar pumping, and it is worse on glass that gets strong direct sun and cool air on the other side, which is a fair description of a south or west-facing window on this island in September. Add the second local accelerator: a glazing pocket that does not drain. If the bottom rabbet of a sash holds water — because the weep holes were caulked shut, because the drainage slots are packed with moss and fir needles, or because the exterior sealant was run along the wrong edge — the edge seal of the unit sits wet for eight months a year and gives up early. I find that constantly, and it is the reason I look at the sash drainage before I quote the glass.

The fix is to replace the sealed unit and keep everything else. On most windows I can take out the glazing stops or pull the sash, extract the failed unit, and set a new one in the same sash, so the frame, the hardware, and the trim are untouched. That is a much smaller job than window replacement and it is usually the right one, because on a house out here the sash and frame are commonly fine and only the glass has failed. What I do not do is drill and vent a fogged unit. Those defogging services take a permanently damaged unit, make it look better for a season or two, and leave you with a vented cavity that is no longer sealed, no longer gas filled, and no longer insulating the way you paid for. I would rather tell you that than sell it.

Ordering the unit is where island reality bites, and I am going to be blunt about it: this is not a same-day repair. Each unit is made to your exact sight size and glass thickness, with the low-emissivity coating on the correct surface, and it has to be built and then trucked over on the ferry as a fragile item. Figure on a couple of weeks between the measuring visit and the installing visit, sometimes longer for a shape, a grid, or an obscure pattern. Some units also have to be tempered, which adds time: current residential code requires safety glazing in doors, in glass beside a door where the bottom edge is under 60 inches and the pane is within 24 inches of the door edge, around tubs and showers below 60 inches, at the bottom of stairways, and in large low panes. I check for that before ordering rather than after, and tempered glass cannot be cut on site, so getting the measurement right is the whole job.

Single panes are a different and much faster story. A broken or cracked single pane in a wood sash, an outbuilding, a garage window, a storm panel, or an old cabin window is a same-visit repair if the size is ordinary: cut the glass, clean the rabbet back to bare wood, bed it properly, set new glazing points, and either putty it or set it in a modern sealant depending on what the window is. Old fir sash reglazed properly will outlast anything I could replace it with. If the opening is boarded and it is January, I will get a temporary panel or poly in on the first visit so the house is dry and secure while the real glass is on order.

Then the moving parts. Old double-hungs on this island are usually one of two systems. The oldest are cord and cast weights running over a pulley in the jamb, where the cotton cord rots and snaps and the sash then drops or has to be propped with a stick — a repair that involves opening the pocket cover, fishing the weight, and rehanging it on new cord, which is fussy but entirely doable and keeps an original window working. Newer double-hungs use spiral, block-and-tackle, or constant-force coil balances behind a vinyl jamb liner, and those are replaceable parts once you can identify them. I also free sashes that have been painted shut, replace broken parting bead and tilt latches, and reset stops so the sash rides without binding. Almost none of that requires a new window, which is what people are usually braced to be told.

Casements and awnings fail at the operator, and salt air is why. The worm-gear operator on a crank window is a cast housing full of small steel gears living a few hundred feet from salt water, and once the grease dries and corrosion gets into it, the crank either seizes or spins with the splines stripped out. Operators, cranks, hinge tracks, and sash locks are stocked parts for the common brands if I can read the stamp on the hardware or the etch in the glass corner, so bringing me a photo of that mark before the visit genuinely saves a trip. Sliders are the same conversation with rollers and tracks instead of gears.

The last piece is weatherstripping the sash itself, and it is worth separating from my window and door weather sealing page. That page is the exterior seal around the opening — the caulk, flashing, and drip cap that keep wind-driven rain out of the wall. This is the seal between the moving sash and the frame: kerf-in bulb seal, leaf and compression weatherstrip, and the interlock on a slider. Both jobs stop drafts, and they are not the same joint. A window can be perfectly sealed to the wall and still whistle at the sash, and in a January southerly you will hear it. On the licensing question, since people ask: glass and glazing work in Washington does not require a separate state trade license the way electrical and plumbing do. It sits inside a general contractor registration, which I hold. What I do not offer is whole-window or door unit replacement, new openings, or roof-level skylight glass, and I will refer those rather than pretend.