Walking Through a Freshly Installed Window in the First Weeks
The day a new window goes in is not the day it is finished. Sealant skins over in an hour and cures over several days, trim gets painted later, and the first hard rain tests flashing that looked fine in dry weather. A walk-through in the first weeks catches the small faults while they are still easy to fix. These are the questions that come up most often when a homeowner in Austin, TX walks around a freshly installed window.
What should the sash do the first time it is opened?
It should move without a fight. A double hung sash slides up and down on its balances and stays where it is left. A casement cranks open smoothly and pulls tight against the weatherstrip when it closes. A slider rolls on its track without a scrape. If any of these drags, rubs or sticks in one corner, the frame was probably set a little out of square or the shims are pressing on a jamb. That is a quick adjustment in the first week and a nuisance after the trim is nailed down.
Try every window in the house the same way, not just the new ones. Cutting a new opening in a wall can shift the framing around it, and a neighboring door or window that used to close easily can start to rub.
How can you tell if the window is level and plumb?
Hold a four foot level against the side jamb and then across the sill. The bubble should sit between the lines on both. A visual check works too: the gap between the sash and the frame should look the same width all the way around. A reveal that tapers from wide to narrow means the unit is twisted in the opening, and no amount of caulk will hide it for long.
Look at the diagonals if the window is large. A picture window or a bay window that was set out of square shows it in the glass stops, where the lines of the frame no longer meet the corners cleanly.
What does good sealant look like?
The exterior joint between the frame and the siding, stucco or stone should be a smooth, continuous bead with no gaps, pinholes or thin spots. It should be pressed into the joint, not just laid over the top. Along the sill the bead is sometimes left open at intervals on certain products so that water behind the unit can drain, and the installer should know which product asks for that. Along the head and the jambs the joint is closed.
Run a finger along the bead after it has cured. It should feel firm and slightly rubbery, and it should not peel away from either surface. A bead that lifts at one end has been applied over dust or a damp surface, and it will let go in the first summer.
Where does water get in when it fails?
Almost always at the sill and the corners. Water that gets behind the siding is meant to run down the face of the house wrap and out over the sill flashing. If the sill pan was skipped, or the tape at the corners was not lapped properly, the water goes into the wall instead. Stains on the drywall below the sill, a soft spot in the sill board, or bubbling paint are the first signs.
The spring storms that come through Travis County are a good test. After the first heavy rain from the west or south, check the inside of each new window, the wall below it and the ceiling under any second floor window. A little patience in the first few months saves a lot of repair work in a wall that has been closed and painted.
Why do some windows fog or sweat on the first cold morning?
A bit of condensation on the inside of the glass on a cold morning is a humidity matter, not a window fault. A shower, a pot of boiling water or a house with a lot of plants adds moisture to the air, and it collects on the coldest surface. Insulated glass with a warm edge spacer keeps the inside surface warmer than a plain double pane unit, so it fogs less often and clears faster.
Fog between the two panes is different. That points to seal failure, and on a new window it is a warranty matter. A crew will not see it on installation day, but it can show up in the first heat wave if a unit was damaged in transit or stored badly. Take a photo and report it early.
What should be checked on the inside trim?
Interior casings should sit tight against the wall with mitered corners that close. A wide gap at a corner often means the opening was out of square and the trim carpenter bridged it with filler. Look at the stool, the shelf at the bottom of the window, for level and for a solid fit against the sash. Gaps behind the casing where daylight shows through are air leaks, and they are easy to see with a flashlight at night from outside.
In a plastered or older house in Clarksville or Tarrytown, the wall around a new opening may need a patch of texture to blend with the old surface. The patch usually shows for a week or two as it dries, then disappears when it is painted.
Does the glass need to be checked?
Look at it in different light, early in the morning and late in the afternoon. Scratches, chips, stuck labels or leftover sealant show clearly at a low angle. Tempered glass carries a small etched mark in one corner, and any window near a door, a tub or the floor should have it. A low e coating can be seen as a faint tint when a pen is held against the glass, and the reflection of the tip will show a second image slightly deeper in the unit.
What is worth writing down?
- The date of installation and the first rain after it
- Any window that sticks, rubs or fails to latch
- Any gap, crack or pinhole in the exterior sealant
- Any stain, bubble or soft spot below a sill
- Any fog between the panes
- Any glass scratch or chip, with a photo
A written list with photos makes a follow up visit short and specific. Memory is a poor record after a month of other house work.
When is the right time to look again?
Once in the first week, once after the first hard rain, and once after the first stretch of hot afternoons. Materials move as they heat up and cool down, and a frame that sat perfectly in April can show a tight corner by July. A west wall near the Colorado River bluffs or on any open lot gets the most of that swing, and a second look in the late afternoon sun shows what the morning did not.
Is a gap around the frame ever normal?
A small, even gap between the frame and the rough opening is normal, because that is where the shims and the foam sit. It is covered by the casing inside and the sealant and cladding outside. A gap you can see daylight through from the inside is not normal, and it should be filled with insulation or foam before the trim goes on. If the trim is already on, a bead of caulk at the casing edge can close small gaps, and larger ones need the casing pulled off.
How do different frames behave in the first months?
A vinyl window can show a slight bow if it was clamped or shimmed unevenly and then heated by sun. A fiberglass window is stiffer and shows less movement. An aluminum window with a thermal break is rigid, though its metal frame gets hot to the touch in the afternoon. A wood window with a clad exterior can show a hairline gap at a joint where the wood has taken on or lost moisture. None of these is a reason for alarm on its own, but each is worth a photograph and a note.
The first month of a new window is its inspection period, and a few quiet checks in that month do most of the work of keeping it dry for years.