Drafts, whistling, or water coming in

Not sure this is what's wrong? Try the free diagnosis quiz — eight questions about what the door is doing, then the likely causes and what is safe to try.

What has probably happened

• The pile weatherstrip along the stiles and the interlock has worn flat, shrunk or fallen out.
• The interlock between the sliding panel and the fixed panel no longer meets because the door has sagged.
• The weep holes in the sill are blocked, so rain pools in the track and comes over the inside edge.
• The caulking or flashing around the frame has failed, so water gets in behind it rather than through the door.
• The panel does not close square, so one corner leaves a gap that whistles in wind and leaks in rain.

What the technician does

• The technician finds where the water or air is actually coming in, which is often not where it shows up.
• Pile weatherstrip replaced on the stiles, the interlock and the header, matched to the door's channel.
• The panel adjusted so the interlock meets along its whole height and the door seals evenly.
• Sill weep holes cleared and the sill checked so it drains outward the way it was designed to.
• Frame caulking and flashing inspected, and an honest word about anything that needs more than a door technician.

Why it happens where you live

Summer storms and hurricane-season rain arrive sideways, and a sill that drains fine in a drizzle floods in wind-driven rain. Sun and heat shrink old weatherstrip until a draft appears, and salt air stiffens the pile so it stops springing back.

Free tools for this

• Draft and leak locatorWhere is the air or water getting in?Open →
• Seasonal prep checklistWhat should I do to my sliding door each season?Open →

Questions people ask

Why does it only leak in a hard storm?

Wind-driven rain pushes water up and over a sill faster than it can drain, and it finds gaps that ordinary rain never reaches. That is usually a drainage or a seal problem at the door, and it is fixable.

Will new weatherstrip stop the draft?

If the strip is worn, yes. If the panel has sagged so the interlock does not meet, the door needs adjusting as well, and the technician will do both so the result holds.

Is this a door problem or a house problem?

Mostly a door problem: seals, drainage and alignment. If the water is getting in behind the frame through failed flashing, the technician will tell you so, rather than fit weatherstrip that cannot fix it.

Something else going on?

• Hard to open or close
• Rollers worn out
• Bent or worn track
• Lock won't catch, handle loose
• Door is off its track
• Broken or foggy glass
• Screen door torn or off

One Call Sliding Door Repair arranges the visit; the technician does the work and gives you the price.