★★★★★ 4.9 from 145+ reviews | Google · Thumbtack · Angi · Yelp | 20-yr glass warranty · 3-yr wood warranty
Open 7 days · 8am–8pm | Fully insured
Call or text(224) 209-0862
★★★★★ 4.9· 145+ reviews· 20-yr glass warranty
Drafts, leaks & insulation · 40+ nearby towns

Leaking Window Repair. Seal Out Drafts & Water.

Drafts and window leaks come from failed seals, not failed windows. We find where air and water get in and seal it — weatherstripping, caulking and insulation — without replacing the window.

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  • All window types & brands
  • Fully insured
  • Price match
Can it be fixed?Usually — resealed and weatherstripped
Typical price$100 – $300per window · confirmed before work starts
How longUsually one visit
Peace of mindPrice agreed before we start
The Problem

Window Leaks and Drafts Come From Failed Seals

A cold draft or a rainy-day leak feels like the window has failed. Almost always, though, the window is fine — it's the seals around it that have worn out, and seals are made to be renewed.

Every window depends on a system of seals to keep air and water out: weatherstripping between the moving sash and the frame, caulk around the exterior and interior perimeter, flashing and drip edge that direct rain away, and insulation in the hidden gap between the frame and the wall.

Over the years these dry out, crack, compress, and pull away — and northern Illinois's freeze-thaw winters and humid summers wear them down from both directions. When they fail, cold air pours in, warm air escapes, and rain finds its way past.

The fix isn't a new window — it's finding every leak point and re-sealing it. Because seals are consumable by design, re-sealing is normal maintenance that restores the window's air- and water-tightness for a small fraction of replacement cost.

Two problems, one repair

Drafts (air leaks) and leaks (water intrusion) often share the same failed seals, so we address both together.

Stopping the air leak improves comfort and cuts energy loss; stopping the water leak protects the frame, sill, and wall from the rot and staining water causes — the same damage our sill repair and rotted wood repair work exists to fix once water has been getting in for too long.

A window leak when it rains, water leaking around the window frame, or a window draft you can feel on cold days usually traces back to the same few places: worn weatherstripping, failed window caulk, or a sash that no longer closes tight.

Finding the real entry point comes first — sealing the wrong spot just moves the water somewhere else.

Not sure this is your problem? Use our window triage guide — pick the symptom and see the likely cause and cost. Related reading: Seasonal window maintenance calendar

Feeling a draft

Cold air you can feel near the window, curtains that move, or a room that's always chilly points to air leaks.

Water during rain

Moisture, dripping, or staining on the sill, wall, or floor after rain means water is getting past the seals.

Rising energy bills

Heating and cooling bills creeping up, or a furnace/AC that runs constantly, often trace to air leaking around windows.

Cracked or missing caulk

Visible gaps, shrunken or crumbling caulk, and flattened weatherstripping are the leak points themselves.

Moisture residue along the bottom of the glass on a wood casement window
Recognize this? It's a common, repairable problem.
Where leaks and drafts get in
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  1. Worn weatherstripping — air slips past the edges of the sash.
  2. Meeting rail gap — sashes that no longer close tight at the lock.
  3. Failed exterior caulk — the joint between the window frame and the wall.
  4. Sill joint — water gets under or behind the sill.
  5. Above the window — flashing, siding or roof leaks. Water shows up at the window but it isn't a window problem — we check for this first.

Points 1–4 are window repairs. Point 5 needs a roofer or siding contractor.

The Fix

How We Seal a Leaking or Drafty Window

Find the Leak Points

We locate every path air and water are taking — weatherstrip, caulk lines, perimeter gaps, glazing, and flashing above the window.

Replace Weatherstripping

Worn or missing weatherstripping between the sash and frame is replaced so the window seals tight when closed.

Re-Caulk & Insulate

Old caulk is removed and replaced, and the hidden gap between frame and wall is insulated where it's missing or thin.

Confirm It's Sealed

We check that the draft is gone and the window is water-tight — backed by our warranty.

Seals & Materials

Weatherstripping Replacement — and Leaks in Vinyl and Aluminum Windows

Weatherstripping is the flexible seal between the sash and frame. It flattens, cracks and falls out over the years, and a window that looks fine can leak air all around. Replacing it — matched to your window's profile, whether foam, felt, pile or rubber bulb — is one of the quickest fixes for a drafty window.

Leaks aren't only a wood-window problem. Vinyl windows most often leak at the frame corners, where welded joints crack, and where exterior caulk has failed. Aluminum sliders leak when the weep holes at the bottom of the track clog, so rainwater backs up inside. Each has its own fix — resealing corners, clearing weep holes, new caulk and weatherstripping.

Repair vs. Replace

Leaking Window Repair Cost

Replacing the window$800 – $2,500+
Repairing itFrom $50

Typical prices

Per window · typical local prices
Weatherstripping replacement$100 – $300
Exterior caulk & reseal around the frame$100 – $350
Alignment so the sash closes tight$50 – $500
Why the final price can differ: these are typical ranges, not quotes. What moves the price: the size and type of glass (tempered, low-E, triple-pane, decorative), how far rot has spread once the wood is opened up, second-story or ladder access, parts availability on discontinued brands, and how many windows are done in the same visit — multi-window jobs cost less per window. Minimum service visit: $150. We confirm and agree the price with you before starting. Compare all repair prices →

Drafts are the classic pitch for full window replacement — but the draft is coming from failed seals, not a fundamentally failed window.

Re-sealing restores air-tightness for a small fraction of replacement cost, and unlike most repairs, this one keeps working for you: by cutting the air leakage that makes your furnace and AC run harder, a sealing job can quietly lower your energy bills every month.

That combination — low cost, real comfort improvement, and ongoing energy savings — makes leak and draft sealing one of the highest-value window services there is. On older wood windows it also preserves the original window rather than replacing it.

Replacement only makes sense when a window is structurally failing across multiple areas at once, which is uncommon; we'll tell you honestly which applies and give you an estimate before any work begins.

Why McHenry County windows leak

Sub-zero January nights shrink caulk and stiffen weatherstripping until it cracks, and wind across open farmland west of Huntley and Marengo drives air through every gap. In spring, wind-driven rain finds any caulk joint that failed over the winter — which is why leak calls peak in April.

DIY or Pro?

Drafty Window Fixes You Can Do Yourself

Safe to do yourself

  • Find drafts on a windy day by holding a lit candle or incense stick near the window edges.
  • Replace foam or felt weatherstripping on basement and storage windows yourself.
  • Use removable rope caulk or window film as a temporary winter fix.
  • Note exactly where water shows up and when — it helps us find the real entry point.

Call a pro

  • Caulking over a leak without finding its source — water gets trapped behind the new caulk.
  • Leaks at the top of the window — they often come from the wall or roof above.
  • Water inside the wall, on the ceiling, or staining below the window — possible hidden damage.
  • Weatherstripping on double-hung sash channels — it is built into the sash and easy to damage.
Warranty

Warranty on Sealing Work

3 yearson wood we rebuild or replace — if it rots, we replace it
20 yearsmanufacturer warranty on insulated glass units
Redoif we install hardware incorrectly, we come back and fix it

Parts we don't make (cranks, balances, locks) carry only their supplier's warranty. Leaks from roofs, flashing or siding aren't window defects. Full warranty terms → · Read our reviews

Got a quote to replace these windows?

Send it to us before you sign. We'll tell you — free — whether a repair would solve it for less.

Free Second Opinion
FAQ

Leaking Window Questions

Cold drafts around a window almost always come from failed air seals rather than the glass itself. The usual culprits are worn or missing weatherstripping (the flexible seal between the sash and frame), cracked or shrunken caulk around the window's exterior and interior, gaps where the frame meets the wall, and missing insulation in the gap between the window frame and the rough opening. Over the years these seals dry out, crack, and pull away, and northern Illinois freeze-thaw cycles accelerate it. The fix is to find every leak point and re-seal it — new weatherstripping, fresh caulk, and insulation where it's missing — which stops the draft without replacing the window.
Yes, and it should be addressed quickly because water intrusion damages far more than the window. Rain getting in around a window usually traces to failed exterior caulk or sealant, worn or missing flashing and drip edge above the window, gaps at the sill or corners, or deteriorated glazing that lets water past the glass. We identify where the water is actually entering — which isn't always where it shows up inside — and seal it properly: re-caulking, addressing flashing, resealing the glazing, and correcting any drainage that's letting water pool. Stopping the leak protects the frame, sill, wall, and interior finishes from the rot and staining water causes.
It can make a real difference. Air leaks around windows are one of the most common sources of energy loss in a home — conditioned air escapes and outside air pours in, so your furnace and air conditioner work harder to hold temperature. Sealing those leaks with fresh weatherstripping, caulk, and insulation reduces that loss directly, which shows up as a more comfortable home and lower heating and cooling bills. It's one of the most cost-effective window services there is: a modest sealing job addresses a problem that's quietly costing you money every month, and it does so for a tiny fraction of window replacement.
In most cases the existing windows can be sealed rather than replaced. Replacement companies often present new windows as the only way to stop drafts, but the draft is coming from failed seals — weatherstripping, caulk, and missing insulation — not from the window being fundamentally beyond help. Re-sealing an existing window restores its air-tightness for a fraction of replacement cost, and on older wood windows it also preserves the original window. Replacement only makes sense when the window itself is structurally failing across multiple areas at once, which is far less common than it's made out to be. We assess honestly and tell you which applies.
They address air leaks in different places. Weatherstripping is the flexible seal between the moving sash and the frame — it stops air from leaking through the gap where the window opens and closes. Window insulation refers to filling the concealed gap between the window frame and the rough opening in the wall, which is a common hidden source of drafts, especially on older installations where that gap was never properly insulated. A thorough draft repair addresses both: we re-establish the weatherstrip seal on the operating parts and insulate and seal the perimeter gap, so air isn't getting in through either path.
The local climate is hard on window seals in both seasons. Northern Illinois winters bring deep cold and repeated freeze-thaw cycles that crack caulk and stiffen weatherstripping, while summer heat and humidity — heavier near Crystal Lake, the Fox River, and the Chain O'Lakes — dry out and degrade sealants from the other direction. Add wind exposure and the age of many local homes' original seals, and it's no surprise that drafts and leaks are among the most common window complaints in the county. Because seals are consumable — they're meant to be renewed periodically — re-sealing is normal maintenance, not a sign the window has failed.
Sometimes water shows up at a window but enters higher — through the roof, the flashing above the window, the siding or a skylight. Those are not window problems, and sealing the window will not stop them. We check before we start and tell you honestly if the source is outside the window, so you do not pay for a repair that cannot work. Roof, flashing and siding leaks are not covered by our warranty.
Yes. We seal drafty and leaking windows throughout 40+ towns within about 40 miles — Lake in the Hills, Crystal Lake, Algonquin, Cary, Huntley, Woodstock and more. Call or text (224) 209-0862.
Weatherstripping replacement typically runs $100–$300 per window, and exterior caulking and resealing $100–$350. If the sash needs adjusting to close tight, that is $50–$500. Our minimum service visit is $150, and sealing several windows in one visit costs less per window.
The most common causes are failed exterior caulk around the frame, worn weatherstripping, a sill that has lost its slope, or blocked drainage holes. Sometimes the water enters higher up — through flashing, siding or the roof — and only shows up at the window. We check before we start.
For a quick winter fix, removable rope caulk or window film helps. The lasting fix is replacing worn weatherstripping, re-caulking the exterior joints and adjusting the sash so it closes tight — usually far cheaper than new windows.
Weatherstripping and re-caulking are usually finished in a single visit. Exterior caulking needs dry weather and mild temperatures to cure properly, so we schedule it accordingly.
More Repairs

More Leak & Draft Repairs

Sill RepairRotted sills rebuilt after water damage.Learn more →Foggy Window RepairFailed glass seals that lose insulation.Learn more →Frame RepairShifted frames that leave gaps.Learn more →Storm WindowsStorm windows repaired for extra protection.Learn more →

Leaks & Drafts in these towns and more

Lake in the HillsCrystal LakeAlgonquinCaryHuntleyCarpentersvilleWoodstockMcHenryMarengoJohnsburgIsland LakeLakewoodAll service areas →

Based in Lake in the Hills, serving homes within about 40 miles.

Seal Out the Drafts.

Call, text, or send a photo. You'll know what's wrong and roughly what it costs — before anyone comes out.

(224) 209-0862Free Quote

★★★★★ 4.9 from 145+ reviews · 20-year glass warranty · Price match