Water Sitting on the Window Sill

A sill with standing water is past the "a little fog" stage. The wood is getting wet on a schedule. You can wipe it forever, and you should wipe it today, and you should also name the schedule. Water every cold morning with no rain is condensation. Water during wind-driven rain is a leak until proven otherwise. Water both times is both. The wipe is the same. The repair is not.

For the condensation schedule, gauge in that room, aim under about 50 percent, cut the humidifier, run the bath fan long enough and to the outdoors, keep the dryer vent clear and actually outside. Open curtains. Wipe until the mornings come up dry. If they do, the sill was a humidity gauge you could see. If the wood is soft, do not wait for perfect habits to sand it. Soft sills need a repair person. Ongoing water plus soft wood is how the spot gets bigger.

For the rain schedule, look at the window, not the shower. Weep holes clogged with paint, caulk in the wrong joint, a storm window that traps water, siding that dumps behind the trim. Photograph the sill during the storm. A window tech or a carpenter can use that photo. Clearing a weep gently is fair. Recaulking every seam because you are frustrated can seal the drain the window needed. If you do not know which joint is supposed to be open, stop and ask.

Between the panes is not sill water. If the sill is dry and the fog is inside the glass, it is a failed seal. If the sill is wet and you can mop it up, the water is on your side or coming through. Do not mix the invoice.

Catch drips so they do not soak the wall below. A towel is fine for a day. A towel as a permanent fixture means you accepted a leak. The wall under a chronic sill leak is the expensive part, not the glass. Stains below the window belong in the photo.

Do not drill the frame. Do not pour cleaner into a puddle on raw wood and call it treated. Dry it, then decide.

Write the schedule in one line. "Clear cold mornings" or "only when the south wind rains." That line is the diagnosis you are allowed to make. The next person can argue with a photo, not with a vibe.

Put a dry paper towel on the sill at bedtime on a clear night and another during the next rain, if you can do the rain one safely from inside. In the morning, or after the storm, the towel tells you which schedule is real. You will stop hedging. Condensation and leaks get different phone calls, and the towel is the sort of evidence those calls respect.

Check the floor and the trim under the sill once, not only the painted wood you already see. Water travels down the wall cavity and shows up as a baseboard stain or a musty smell at the carpet edge. If that edge is wet, the sill is no longer a surface chore. It is a wall that a pro should understand before you set a bookcase in front of it.

Until the schedule stops, wipe. A sill that stays wet while you collect quotes is still taking on damage. The quote does not dry the wood. A towel does, partly, and only for the water that made it to the surface. Keep the photos anyway so the repair matches the cause.

If someone in the house is getting worse, that is a doctor conversation, and opening walls or the furnace cabinet is a job for a licensed pro.

Wet sills are a picture page in the ClearNest guide When Your House Doesn't Feel Right. $2.99 at https://clearnestair.com/book.