Can I make a warranty claim without a copy of my warranty?

Yes. Request it from the contractor in writing, contact the manufacturer directly with your model info, or use the CSLB license bond if the contractor is unresponsive.

What does the CSLB license bond cover for defective installs?

Financial losses from installation defects a licensed contractor refuses to repair — up to $25,000. File a CSLB complaint to initiate the process.

How do I tell if the problem is the installer or the manufacturer?

Condensation between panes is almost always a manufacturer defect. Flashing, shimming, and air sealing failures are installer defects. Water infiltration requires inspection to determine which failure mode applies.

Can I fix a failed window install myself, or does it void the warranty?

Most install warranties have a clause prohibiting homeowner modification of the installed work — touching flashing, sealant, trim, or anchoring yourself typically voids the install warranty for that opening. Take the documentation path first: photograph, contact the contractor in writing, request an inspection. If the contractor responds and repairs the defect, you're covered. If they refuse, file CSLB and pursue the bond. DIY repairs are a last resort when all other paths are exhausted — at that point the warranty is already compromised.

How soon after a window install should problems become visible?

Draft and air-seal failures are often immediate — a cold day in January will reveal them within weeks. Frame-racking issues (sash won't operate or lock) typically show up within 3–6 months as the house settles into the new installation. Paint bubbling and mineral staining from water infiltration usually appear in year 2–4 — after enough rain events have moved enough moisture through the failed flashing. Seal failures in the IGU (condensation between panes) typically appear in years 5–12, which is why glass warranties run longer than install warranties. If you're at the 2–4 year mark, do a walkthrough with this guide — it's the window where install defects are most likely to appear and when you're most likely to still have warranty coverage.

How-To & Process

How to Spot a Failed Window Install (Before the Warranty Runs Out)

Q: How long does a window install warranty typically last?

2-year labor is the industry floor; reputable shops offer 5–10 years or lifetime. The manufacturer's product warranty is separate and runs longer.

Q: Is a lifetime install warranty transferable when I sell?

Only if the warranty document says so. Ask in writing before closing — some are homeowner-specific, others transfer. It matters to buyers.

By Israel AquinoFebruary 20, 20268 min read

TL;DR

A failed window install usually shows up as a drafty corner, a paint bubble near the sill, or efflorescence on the exterior — not as an obvious leak. The eight signs that matter: corner drafts, sill paint failure, condensation between panes, a racked frame that won't lock, trim gaps, mineral staining, cracking caulk at the head, and soft material near the sill. If you find any of these, document first, then contact the contractor in writing. If they're unresponsive, CSLB's license bond covers installation defects.

We've replaced a lot of windows that were replaced by someone else first. Bad installs don't announce themselves — they show up as a drafty corner in winter, a paint bubble near the sill in year 3, and a rotted rough opening by year 7. Most of these failures are visible if you know what to look for. Here's how to inspect a recent (or not-so-recent) window install yourself.

Most install warranties in California run 2–10 years on labor; some contractors offer lifetime. The window manufacturer's product warranty is separate and runs longer. The window that's failing on you may still be under one or both — but only if you catch the problem and document it before the clock runs out. A missed deadline is a missed claim.

Walk your windows with this guide. All you need is a flashlight, a flat-blade screwdriver, and your hands. You don't need to open walls or pull trim to find most of these problems.

Eight signs of a failed install — inspect these now

What to look for, and what each sign means.

1
Draft at the corner where frame meets wall
Hold your hand at the interior corner where the window frame meets the drywall or plaster. On a cold or windy day, a failed air seal is obvious. What it means: foam-only air seals break down within 3–5 years as the house moves. A correct install uses closed-cell backer rod plus sealant behind the trim, not just a shot of low-expansion foam visible at the surface. If you feel air, the primary seal failed.
2
Paint bubbling or peeling at the sill
Check the interior sill and the wall surface directly below the window. Bubbling or peeling paint — especially if it showed up within 1–4 years of a new install — means water is infiltrating behind the frame. The most common cause is a flashing membrane that was missing, improperly lapped, or not tied into the drainage plane correctly. The paint is a symptom; the water damage behind the drywall is the actual problem.
3
Condensation between panes
If you can see fogging or moisture trapped between the glass layers on a double or triple-pane unit, the insulated glass unit (IGU) seal has failed. This is a glass problem, not an install problem — the IGU edge seal is a manufacturer defect. However, the installer should have registered the manufacturer warranty at time of install. If they didn't, you may have no recourse against the manufacturer. Call the window brand directly with your model number and install date.
4
Window operates stiff or won't lock flush
A casement that takes real force to crank, a slider that jumps the track, or a single-hung that won't lock because the sashes don't line up — all of these point to a racked frame. At install, the frame should be shimmed plumb and square before it's fastened. If shimming was skipped, or the rough opening shifted post-install (common in older LA homes with wood framing), the frame torques out of square and the sash binds. This is almost always an install defect unless you've had significant foundation movement.
5
Trim gaps opening up at the jambs or head
If the interior casing or exterior trim has pulled away from the wall or the window frame, the window frame itself has moved. The most common cause is low-expansion foam that continued expanding after the trim was installed, slowly pushing the frame outward. A correctly installed window uses foam sparingly and relies on fasteners — not foam — to hold position. Gaps at the trim usually mean the frame shifted after cure.
6
Efflorescence (white mineral staining) on the exterior sill
White chalky deposits on stucco or masonry below a window are a sign of water traveling through the rough opening and carrying dissolved minerals out through the wall. This means the drainage plane behind the window failed — either the sill pan wasn't installed, wasn't sloped, or wasn't tied into the water-resistive barrier (WRB) correctly. This staining is telling you water has been running through your wall framing, not just down the face.
7
Caulk cracking at the head and jambs
Visible exterior caulk at the window perimeter is a backup seal — it is not supposed to be the primary water management system. The primary seal is a flashing membrane and drainage plane behind the frame. When exterior caulk cracks, it fails as a backup, but that's not the real problem. The real problem is that water is now reaching the head of the window with no secondary defense. Cracked head caulk is a higher-priority issue than cracked sill caulk because water runs down, not up.
8
Soft floor or wall material near the sill
Press the floor directly in front of the window and the drywall below the sill. Softness, sponginess, or visible staining at the baseboard means water damage has extended into the framing — subfloor, bottom plate, or wall studs. This is the worst-case scenario. Stop using the window if you find this, get an independent building inspector or structural contractor out immediately, and document everything with photos before anyone touches it. Repair costs at this stage typically run $3,000–$12,000 above the window replacement itself.

The flashing test — can you see the membrane?

How to check whether flashing was actually installed.

Flashing is the most skipped step in the LA window installation market. It adds time and material cost, it's invisible once the trim goes on, and most homeowners don't know to ask about it. If your contractor photographed flashing during the install, you have documentation. If not, here's how to look.

On a full-frame install, you should be able to see a black or blue membrane on the sill pan if you carefully remove the interior trim at the sill. The membrane should run continuously from the sill up the jambs and lap under the head flashing — you should see it at all four corners. On a retrofit (block-frame) install, the sill should be taped with butyl tape and a liquid-applied product that bridges the gap between the existing frame and the new unit. Neither should be invisible — both materials have visible color and texture.

No visible membrane means either it's hidden by trim on a correctly installed job (possible), or it wasn't installed at all (red flag). The way to tell the difference is to ask the contractor for installation photos taken during the job. Any contractor who photographs their work can produce these within a day. If they can't or won't, that's your answer.

If you suspect a flashing miss, call an independent building inspector before you call the contractor. You want written documentation of what was found — and what wasn't — before you open any conversation about warranty claims or remediation. An inspector's report changes the dynamic. A homeowner complaint without documentation does not.

What to do if you find a problem

Five steps, in order.

1
Document with photos before you do anything
Date-stamped photos are the foundation of any warranty claim. Photograph the problem from multiple distances — wide to show context, close to show detail. If there's moisture, photograph when it's actively visible. Don't wipe it up, don't paint over it, don't call anyone until you have documentation. Your phone's timestamp metadata matters; if you share via email or text, the send timestamp adds another layer.
2
Check your paperwork for the install warranty terms
A lifetime install warranty and a 2-year labor warranty are not the same thing, and the gap between them is where most disputes live. Pull your original contract and any warranty certificate provided at completion. Look specifically for: what is covered (labor only, or labor and materials?), what voids the warranty (homeowner modification, adjacent contractor work), and the notice procedure (email vs certified mail vs their specific form). If you don't have paperwork, request it in writing before raising the defect claim.
3
Contact the contractor in writing
Email, not phone. A phone call creates no record. An email creates a timestamped record of what you reported, when you reported it, and what you asked for. Keep the first contact factual and specific: describe the symptom, the location, the date you first observed it, and what documentation you have. Don't characterize blame in the first message — just report. Request an inspection date in writing.
4
If the contractor is unresponsive, file with CSLB
The California Contractors State License Board administers a license bond that covers installation defects on licensed contractor work. Filing a complaint creates a formal record, triggers the contractor's response obligation, and may result in mediation or bond claim. You can file at cslb.ca.gov. Include your documentation, the contractor's license number (should be on your contract), and a clear description of the defect. CSLB action is slower than you want it to be — but it matters, especially if the contractor becomes unresponsive or disputes the claim.
5
For glass unit failures, contact the manufacturer directly
If the defect is condensation between panes or a visible glass seal failure, that is a product warranty claim against the window manufacturer — not an install warranty claim against the contractor. Call the manufacturer's warranty line with your window's model number, serial number (usually etched into the corner of the glass or stamped on the frame), and installation date. If the contractor registered the product warranty at install, the process is straightforward. If they didn't, you may need to provide proof of purchase and install date yourself.

Installer vs manufacturer defect — quick reference

Which warranty applies to which failure — and who to call first.

What we mean

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Installer vs manufacturer — who is responsible?

How to tell if the problem is the installer or the window brand.

This distinction matters because the two warranty systems are completely separate. Confusing them is the most common mistake homeowners make when pursuing a defect claim — and contractors count on that confusion to redirect blame.

Glass seal failure — condensation appearing between panes — is almost always a manufacturer defect. The insulated glass unit edge seal is a factory assembly, not an install component. The installer's job is to handle the unit carefully and register the product warranty; they don't manufacture the seal. If your IGU is fogged, call the window brand first, not the installer.

Flashing, shimming, anchoring, and air sealing failures are installer failures. These are field operations performed by the crew on your property. No amount of product quality compensates for missing flashing or an unshimmed frame. If water is getting behind the frame, if the frame is racked, if the air seal is failing — that's the contractor.

Water infiltration is the gray area. If the glass unit is intact and correctly seated but water is getting behind the frame, that's the installer's flashing system — drainage plane failure, not a product defect. If water is entering because the IG unit's edge seal failed and the seal gap is the entry point, that's the manufacturer's product defect. A building inspector or forensic moisture consultant can tell you which failure mode you're looking at — and that determination changes which warranty you pursue.

What people ask

Install warranty questions we get every week.

01How long does a window install warranty typically last in California?

It varies significantly by contractor. Most licensed installers in LA offer a 2-year labor warranty at minimum — this is essentially the industry floor. Reputable shops offer 5–10 years. A small number, us included, offer a lifetime install warranty on workmanship. The window manufacturer's product warranty is separate and typically runs 10–20 years on the glass, lifetime on the frame. Always read both documents before signing a contract — the warranty terms should be explicitly listed, not just promised verbally.

02Can I make a warranty claim if I don't have a copy of my install warranty?

Yes, but it's harder. Request the warranty documentation from the contractor in writing — they are obligated to provide it. If the contractor is out of business or unresponsive, check whether the manufacturer's product warranty was registered (contact the window brand directly with your model info). If the contractor was licensed, CSLB has the license bond on record regardless of your paperwork situation. Always lead any claim with your install date, your address, and the contractor's license number — those are the identifiers that matter most.

03What does the CSLB license bond actually cover for defective work?

The contractor license bond (currently $25,000 in California) covers financial losses resulting from a licensed contractor's failure to perform contracted work, including installation defects that the contractor refuses to repair. It does not cover manufacturer product defects, homeowner damage, or normal wear. Filing a CSLB complaint is the first step — the board can mediate the dispute or direct the bonding company to evaluate the claim. The bond is not a guarantee of full recovery; it's a mechanism for formal dispute resolution when the contractor won't respond.

04Is a 'lifetime' install warranty transferable when I sell the house?

Depends entirely on the contractor's warranty terms — there's no California statute that governs this. Some lifetime warranties are homeowner-specific and expire at sale; others transfer to subsequent owners. Read the warranty document for a 'transferability' clause. If it's not addressed, ask the contractor in writing before closing. A transferable lifetime install warranty adds real value at sale — buyers' agents know the difference — and it's worth verifying you actually have one rather than assuming.

05How do I find an independent inspector to assess my windows?

Three options. First, a licensed building inspector — not a home inspector, but a licensed contractor (B General or C-17 Glazing in California) who specializes in forensic moisture or building envelope work. Second, a certified home inspector (CREIA or ASHI) with specific window and moisture experience — ask directly whether they assess flashing systems. Third, a licensed general contractor who does window work but has no relationship with your original installer. Get the assessment in writing before you make any warranty claims — verbal opinions don't create records.

06What if the original installer is no longer in business?

You have two remaining options. The window manufacturer's product warranty survives contractor closure — contact the brand directly with your install documentation. And if the contractor held a CSLB license, the license bond may still be accessible depending on when the contractor went out of business and whether the bond was active at time of install. File a CSLB complaint either way — they maintain records and can advise on bond availability. For install defects where neither option applies, your homeowner's insurance policy may cover resulting water damage, though not the remediation work itself.

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