How often should you recaulk exterior windows and doors?
Updated July 2026
Plan to recaulk the joints around exterior windows, doors, and trim about every 5 years, and give the beads a quick yearly inspection so you catch a failure before the wall does. The interval depends almost entirely on what went in last time: builder-grade acrylic latex can crack and pull away in 3–5 years, while a quality polyurethane or silicone bead holds 10–20. Caulk is not decoration here, it is the last barrier between wind-driven rain and the framing behind your siding.
What changes the interval
| Your situation | Interval | Why |
|---|---|---|
| Cheap acrylic latex caulk | Every 3–5 years | It gets brittle and shrinks fast, especially on sun-baked south and west walls |
| Siliconized acrylic (paintable) | Every 5–10 years | The common exterior compromise: flexes reasonably and takes paint |
| Polyurethane or hybrid sealant | Every 10–15 years | Sticks and stretches far better; worth the extra $3–5 a tube on windows |
| Pure silicone | Every 15–20 years | Longest life but will not accept paint, so reserve it for unpainted joints |
| Harsh sun / big temperature swings | Inspect twice a year | Expansion and contraction is what tears a bead loose first |
| Coastal or freeze-thaw climate | Every 3–5 years regardless | Salt, UV, and ice cycles all shorten any caulk |
The cost of skipping it
What skipping it costs: a failed bead is a funnel. Water rides the gap behind the trim into the wall cavity, where it rots sheathing and framing and grows mold you cannot see. By the time paint bubbles or trim goes soft, you are looking at $500–3,000 to open the wall, replace rotted wood, and re-side, far more if it reached a window sill or header. There is a comfort tax too: bad seals leak conditioned air and add roughly 5–10% to heating and cooling bills. A tube of good sealant is $5–12.
How to do it (2–4 hours for a house of windows · DIY)
- Inspect on a dry day: press each bead and look for cracks, gaps, chalking, or caulk that has pulled away from the surface.
- Dig out the old failed caulk with a putty knife or caulk-removal tool; a bead over the top of failing caulk will not last.
- Wipe the joint clean and let it dry fully; caulk will not bond to dust or damp.
- Run a smooth bead of exterior polyurethane or siliconized acrylic, then tool it with a wet finger or spoon so it seals both faces.
- Leave the drainage gaps alone: do not caulk window weep holes or the bottom edge of horizontal siding, or you trap water in.
- Let it cure per the label (often 24 hours) before rain or repainting.
Knowing the interval is the easy half. OnOtto reminds you at the right interval, and it won't let you snooze it into next year. Tasks persist until they're done, and completing exterior recaulking schedules the next one automatically.
Put this on autopilot, free for 30 daysFrequently asked questions
What is the best caulk for exterior windows?
For painted trim, a quality siliconized acrylic or, better, a polyurethane or hybrid sealant gives you flex, adhesion, and paintability. Pure silicone lasts longest and sheds water best but will not take paint, so save it for unpainted metal or masonry joints. Whatever you pick, buy an exterior-rated tube (usually $5–12) and check the temperature range on the label; the cheap interior acrylic that fails in three years is a false economy on a wall that sees sun and rain.
Where should you never caulk on the outside of a house?
Two places, and getting this wrong causes the rot you were trying to prevent. Do not seal the small weep holes at the bottom of vinyl or metal window frames; those exist to drain water that gets in. And do not caulk the bottom edge of horizontal lap siding or the underside of a window's bottom trim, because walls are designed to drain and dry downward. Caulk the top and sides so water sheds over the joint, and leave the bottom open to weep.
How do I know my exterior caulk has failed?
Look for beads that are cracked, chalky, or have shrunk into a visible gap between the caulk and the surface. Press it: good caulk is still rubbery, dead caulk is hard or crumbly. Peeling or bubbling paint next to a joint and interior drafts near a window on a windy day are secondary tells. Catch it at the yearly inspection and you re-caulk one window for a few dollars; miss it and you find out when the wall behind it is already wet.
Can I just caulk over the old caulk?
Not if the old caulk has failed. New sealant bonds to the surface underneath it, so a fresh bead laid over cracked, chalky, or lifting caulk sticks to the failure, not the wall, and pulls away within a season. Dig the old material out with a putty knife or a dedicated removal tool, clean the joint, let it dry, then apply. The removal is the tedious part; the actual re-caulking is quick, which is why yearly inspection beats a total redo.