Double Glazing Repairs After Storm Damage: What to Do
When a storm rips through, windows tell the story. Leaves paste themselves to the frames, branches scuff the beads, seals whistle in the wind, and sometimes the worst happens: panes crack, units fog, or entire sashes move out of square. I have spent enough damp mornings with a moisture meter and a crowbar to know the difference between a quick fix and a slow leak that turns into mould behind the plaster. The good news is that most double glazing can be made right, often without replacing the entire window. The key is knowing what to check, how fast to act, and when to call in specialist help.
First hour after the storm
Safety comes first. If glass is visibly cracked or broken, keep children and pets away from the area. Tape a sturdy plastic sheet or a bin bag across the inside face to stop shards falling and to hold in heat until a repairer arrives. If the frame has shifted or is jamming, do not force it back closed with brute strength. That can twist the hinges and turn a repair into a replacement.
Once the immediate hazards are contained, take photos, inside and out, before you clean anything. You may need them for insurance, and a good glazier can read a lot from the pattern of damage. Capture close-ups of cracked corners, torn gaskets, dented aluminium cladding, and dislodged trickle vents. Photograph the whole elevation as well, so an assessor can see nearby trees or flying debris that might have caused impact damage.
Storms are sneaky. Even if the glass looks intact, wind-driven rain finds the smallest weakness. Run a tissue along the interior cill, frame junctions, and the bottom of the glazing bead. Any dampness means water has got past the outer seals or wept through drainage and pooled. Water inside a sealed unit is different to water on the internal frame. Learn to tell them apart. If there are droplets trapped between the two panes that you cannot wipe away, that is a blown unit rather than a leaky frame.
Understanding what actually fails in a storm
Most modern double glazing uses a sealed insulating glass unit (IGU) set into a uPVC, timber, or aluminium frame. A storm can affect the unit, the frame, or the hardware, each with its own remedy.
The sealed unit: This is two panes divided by a spacer bar and a hermetic edge seal. Many units are argon-filled with a low-e coating to improve heat retention. A hard impact can crack a pane, obviously, but more often a storm agitates water that is already collecting in the frame’s drainage channels. If that water sits against a compromised edge seal, the desiccant in the spacer saturates, the unit draws in moisture, and fogging begins over the next days or weeks. Misted Double Glazing Repairs target this exact failure. You cannot dry the cavity in-situ reliably. The unit must be replaced like-for-like.
The frame: uPVC tolerates water well, but repeated UV exposure and age Misted Window Repairs harden gasket seals. High pressure wind forces can flex a sash, and once the weatherstrip loses compression you get draughts and water on the internal cill. Timber copes until paint films crack, then wet rot takes hold at lower rails and glazing beads. Aluminium rarely rots, but its mitred joints and thermal breaks have sealant that can degrade. The fix might be as simple as renewing beads and gaskets, or as involved as scarfing in new timber sections.
The hardware: Hinges (friction stays), espagnolettes, and handle spindles wear quietly. A storm exposes that wear. Sashes rattle in gusts, multi-point locks pull unevenly, and a hinge with too little friction lets the sash creep open. Hardware replacements are often quick wins. I have swapped a pair of top-hung friction stays in under an hour and resolved both leaks and draughts immediately.
Can you fix blown double glazing, or is replacement the only answer?
People ask this a lot when a storm seems to be the culprit. The short answer depends on what you mean by “fix.”
If the unit is misted between panes because the edge seal failed, the thermally efficient performance has already dropped. The U-value worsens, and on cold mornings you might see condensation patterns that mimic fingerprints or smears within the cavity. There are outfits that drill small holes and claim to ventilate or “restore” the unit. In my experience, and in the performance data I trust, this is a temporary aesthetic patch at best. It does not re-establish a proper moisture barrier or argon fill, and the hole vents often clog. For lasting performance, replacing the IGU is the correct approach.
If the glass is intact but the sash or frame leaks around it, that is a different scenario. You can fix that without replacing the unit. I have renewed glazing packers, replaced perished gaskets, and re-seated beads to stop water tracking behind the glass. In timber, you can reseal glazing rebates with modern low-modulus silicone or glazing tapes, then refit timber beads with stainless pins and flexible paint. For uPVC, a new co-extruded wedge gasket can transform both airtightness and water shedding.
So, Can you Fix Blown Double Glazing? If “blown” means fogged between panes, replace the unit. If “blown” means draughty or leaky but without internal misting, repairs to sealing, gaskets, and hardware usually do the job and cost less.
CST Double Glazing Repairs4 Mill Ln
Cottesmore
Oakham
LE15 7DL
Phone: +44 7973 682562
The inspection I carry out on every storm-damaged window
I start outside, head to toe, and finish inside with a torch. A ladder and a respectful attitude to slippery cills help. On the exterior, I look for scuffs, cracks in PVC welds at the mitres, missing gasket tails at the corners, broken glazing beads, and blocked weep holes. Weep holes are small slots at the bottom of the frame that let water escape. If they are clogged with paint or dirt, water will find other routes, including into your plaster. In timber, I probe the lower beads and cill ends with a screwdriver. Softness means rot starting. In aluminium, I check pressure plate screws and cover caps.
Inside, I close the window, engage the locks, then hold a strip of tissue around the perimeter. If the tissue flutters in a stiff breeze while the window is latched, the compression is off, the hinges are bent, or the weatherstrip is worn. A card test helps too. Slide a business card between the sash and frame and close the window. If it pulls out with no resistance, your seal is no longer biting. Finally, I inspect the glazing. Fogging between panes is obvious, but look for staining or cloudy bands near the spacer bar, which often shows early seal failure before full misting.
Hardware gets a workout. Handles should turn smoothly with a firm stop. If you feel a crunch or dead travel, the gear box could be cracked. Hinges should hold position without droop. If a heavy side-hung sash drags at the bottom corner, the stays may be worn or the sash set has slipped. Either can ruin a seal in storm conditions.
Making emergency temporary fixes that actually help
Temporary patches buy you time and protect the fabric of the house. Done right, they stop further water ingress without making permanent work harder later.
For cracked glass, use clear packing tape across the crack in a crosshatch and then apply a polythene sheet on the inside, taped to the frame rather than the sash if you can reach it. This reduces pressure on the damaged unit and keeps shards contained. Avoid spray foams around a window opening as a stopgap unless you know the expansion pressure. Over-expansion can bow a frame and make the sash bind.
For leaking frames, clear the weep holes using a cable tie and flush with a little water to confirm flow. Remove any debris lodged in the exterior bead line. Where gaskets have shrunk back at the corners, you can bridge the gap with a small piece of matching gasket trimmed to a tight fit. It is not a permanent fix, but it will usually stop a drip during the next rain.
If a hinge is loose and the sash back drafts, you can increase friction with the small screws on many friction stays, but do not over-tighten. If the hinge is bent, the adjusters cannot save it. Keep the sash latched and call a fitter to swap the stays.
What insurance typically covers, and how to document your claim
Policies vary. In most regions, storm damage is covered where an insured peril can be shown, such as wind speeds above a given threshold or impact from flying debris. Age-related deterioration is not. That distinction matters when you are arguing for Misted Double Glazing Repairs after weather. If the storm simply revealed a failure that would have happened anyway due to old seals, an insurer may decline.
Help your case with a clear timeline. Provide the photos you took, note the date and the weather conditions, and list what was functioning before the storm. If you had no misting before the event and visible fogging appeared within a day or two, include that detail. A written note from a qualified glazier stating that impact or pressure differentials likely caused an edge seal failure strengthens a claim.
Keep invoices for temporary materials and any emergency callout fees. Insurers often reimburse reasonable costs to prevent further damage. Do not dispose of damaged units until the assessor has seen them or you have explicit permission.
Repair options, from cheapest to most durable
In practice, there is usually a spectrum. The right choice depends on budget, the age of the installation, and how long you plan to stay in the property.
Seals and drainage: Replacing perished outer gaskets and clearing drainage is quick and inexpensive. Expect to pay modestly per opening, less if multiple windows use standard gasket profiles. I have seen uPVC windows go from whistling in a gale to quiet and dry within an afternoon with nothing more than new wedge gaskets and a bead reseat.
Hardware replacement: New handles, locks, and friction stays transform operation and sealing pressure. Parts are affordable, and labour is straightforward when screws and fixings are accessible. If your sash has dropped a few millimetres, hinge packers and adjustments often restore alignment.
Unit replacement: If the IGU is blown, replacing the glass is the only route to restore thermal efficiency. For typical sizes, glass swap costs sit roughly in the low hundreds per unit, rising with large or shaped panes, toughened or laminated glass, and warm-edge spacer upgrades. Keep the frames if they are sound. Good installers measure the sightlines carefully so the new unit sits on proper packers and drains correctly. Ask for a low-e coated unit to match or improve performance, and consider a warm-edge spacer to trim condensation risk.
Frame repairs: Timber repairs involve cutting out rot, splicing in new sections, and reinstating glazing beads with modern bedding compounds. In uPVC, cracks at welded corners are harder to repair invisibly, though there are structural adhesives that can help. If the frame is out of square due to building movement, you can sometimes adjust fixings and packers to relieve twist. Extreme cases call for replacement.
Whole window replacement: Reserve this for systemic failures. If multiple sashes are loose, the frames are bowed, and seals have hardened across the elevation, replacing like-for-like may be cheaper over 10 years than piecemeal fixes. Factor in energy bills, security, and the value of modern multi-point locking.
Common myths about storm damage and double glazing
I hear the same claims on jobs and in the pub. Most contain a grain of truth but lead to bad decisions.
“Condensation inside means the window is leaking.” Not always. Condensation between panes is a blown unit, while condensation on the inner pane can result from high indoor humidity. After a storm, houses sometimes get sealed tight, and without trickle ventilation moisture builds. Before you blame the window, check indoor humidity with a small hygrometer. Aim for 40 to 60 percent.
“uPVC does not need maintenance.” It needs less than timber, but it still needs it. Gaskets flatten, hinges wear, and drainage holes clog. A 20-minute annual service with a vacuum nozzle, soapy water, and a few drops of silicone lubricant on the moving parts prevents many storm problems.
“Drilling and venting blown units restores them.” It might clear visible mist briefly. It does not restore the sealed environment or insulating value. The fog often returns, and sometimes you end up with dust or streaking inside the cavity.
“Storm damage always means replacement.” It does not. I have salvaged many frames with thoughtful work. Start with a proper assessment, then pick the least invasive fix that delivers performance.
The telltale signs a unit has failed versus a frame problem
Homeowners often ask me to confirm what they are seeing. The patterns are consistent.
A failed unit shows persistent fog or droplets trapped between panes that change slowly with temperature. The fog may form a crescent at the bottom or a band around the spacer. It will not wipe away from either side. If only one room’s windows show this after a storm, look at the windward side where pressure hit hardest. That is often where the weakest edge seal gives first.
A frame problem shows water on the cill after heavy rain, draughts felt at certain corners, or a whistling sound in wind. You may see damp patches at wall reveals where the frame meets masonry. A torch shone across the gasket line can reveal tiny gaps. Sashes that need a lift to latch, or handles that refuse to lock without a yank, tell me the alignment has shifted. That can be from wear, but a hard gust can nudge things out.
How professionals approach Misted Double Glazing Repairs
A careful glazier starts by measuring the exact visible glass size and depth. Units are not all the same thickness. Spacer bars vary, and the rebate must hold the unit with even compression and clear drainage. I like to measure three times, note the spacer bar width and color if we are matching aesthetics, and specify low-e coating location to maintain performance.
On the day of the swap, beads come off in a specific order so they go back cleanly. Packers under the unit are adjusted to square the sash, taking weight off the hinges. With the new unit in, the beads engage with a firm click, and the gasket line sits smooth and close, no ripples. Outside, I confirm weep holes shed water freely. Inside, I test the locks and alignment again. A good swap is fast, clean, and leaves the room looking untouched apart from clearer glass.
Some homeowners use this moment to upgrade. If your units were older clear float glass, switching to modern low-e and warm-edge spacers can shave a noticeable amount off heating bills. If you live on a noisy road, acoustic laminated glass can add calm without changing the frames. Storms are inconvenient, but they sometimes nudge useful improvements.
Preventive care that pays off before the next storm
A routine in spring and autumn does more than good looks. Wash the frames and glass, then inspect carefully. Renew any shrinking or hardened rubber. Keep trickle vents clean and working. Lubricate handles and hinge pivots with a silicone-safe product in a small amount. Confirm weep holes drain by dribbling a little water into the external channel and watching it exit freely.
Inside, manage humidity with extraction in kitchens and bathrooms. If your house has tight modern windows and no mechanical ventilation, consider running trickle vents or cracking a window briefly during cooking and showering. Drying laundry indoors without ventilation guarantees condensation, which only complicates diagnosis after a storm.
If you live in an exposed location, shelter makes a difference. Strategic planting or a fence panel can slow wind and reduce flying debris. Keep trees pruned away from glazing planes to prevent branch strikes. Anchor garden items that otherwise become airborne. I have seen a metal bistro chair punch through a toughened unit in a squall. It is as dramatic and expensive as it sounds.
Working with the right professional
Double Glazing Repairs are not all equal. Look for someone who asks more questions than they answer in the first minute. They should want measurements, photos, and a description of how the problem behaves in different weather. Credentials help, but nothing beats references and specific experience with your frame type.
Ask about lead times for replacement units. Standard sizes can arrive in a few days, but special coatings, laminated glass, or shaped panes can take a week or two. If your window is currently vulnerable, ask for a secure temporary board or a polycarbonate insert. A reputable company will respect your home, protect floors, and leave no mess.
Discuss warranties sensibly. A new IGU should carry a warranty from the glass supplier, often around 5 to 10 years depending on region and specification. Labour warranties vary. Be wary of promises that sound too generous without written terms. And keep the paperwork. If you sell the house, a clear record of recent repairs is a small asset.
A realistic sense of costs and timeframes
Prices swing with region and specification, but there are patterns I see across many jobs. Minor sealing and hinge adjustments might cost less than a nice dinner out and can be done same day. Replacing a pair of friction stays or an espagnolette lock sits in the moderate range once parts are sourced. A standard double-glazed unit swap often lands in the low hundreds, scaling up with size, toughened or laminated glass, and special spacers. On a three-bedroom house after a big storm, a mixed bag of three unit swaps, two sets of hinges, and a handful of gasket renewals can be completed over one to two days of labour, plus glass lead time.
Do not forget scaffolding or access if upper floors are involved. Some replacements can be done from inside, but long or heavy units are safer with proper access. If you live in a conservation area with timber sashes, expect longer timelines for joinery and painting between dry spells.
When replacement is wiser than repair
I love saving old windows when it makes sense, but I also know when to step back. If the frames are 25 years old, gaskets have flattened, hinges sag, and you have multiple blown units, the arithmetic shifts. The total of many small fixes can approach the cost of new windows that meet current energy standards and carry a fresh warranty. Add in the comfort benefits and better hardware, and replacement wins.
If a storm makes a structural issue obvious, such as frames fitted without proper packers or fixings, or sashes that were never square, you may be chasing symptoms. An honest installer will show you the installation faults and price a proper remedy rather than papering over the top.
A neighbour’s storm story that captures the choices
One winter, a coastal squall put a crack down the lower corner of a neighbour’s patio door and left a fogged band in a bedroom casement. The door was a large toughened unit, heavy and expensive. He assumed the whole door had to go. We looked together. The frame was true, the lock engaged smoothly, and the threshold was dry. The fix was a new toughened IGU in the existing sash, ordered to size with a warm-edge spacer to reduce winter condensation. For the bedroom, the unit had failed at the bottom where water sits longest. We replaced that IGU and added small packers to keep it off the drainage path. He also had a top-hung window that whistled. Two new friction stays and fresh wedge gasket cured the noise. Total time on-site: half a day. Cost: a fraction of full replacements. The house felt tighter, quieter, and the heating clicked on less often. Sometimes storms give you the nudge to catch up on maintenance and pick up a performance upgrade while you are at it.
Straight answers to common questions
Can you Fix Blown Double Glazing without replacing the glass? If the blowing is true cavity misting, no, not in a way that restores energy performance and lasts. Replace the unit. If “blown” means draughty or leaking around the edges, you can often fix it with new gaskets, packers, and hardware adjustments.
How urgent is misted glass? It is not an emergency for safety, but it signals lost insulation. Left long enough, moisture can stain spacer bars and inner coatings. If you can, plan a replacement within weeks to a couple of months. Cracked glass is urgent and should be made safe immediately.
Can a storm cause delayed failure? Yes. Pressure and flexing can push a marginal seal over the edge, with misting showing days or weeks later. Keep an eye on previously sound units after a big blow.
Is toughened or laminated glass worth it? For doors, low-level glazing, and exposed positions, yes. Toughened resists impact well, and laminated adds security and noise reduction. If flying debris is a risk, laminated inner panes prevent dangerous shards even if the outer breaks.
What about energy upgrades during repairs? If you are replacing units, ask for modern low-e coatings and warm-edge spacers. The price increase is small relative to labour, and the comfort gain is real.
A simple damage and repair checklist to keep handy
- Photograph damage and note dates and weather.
- Make safe: tape cracks, clear weep holes, secure sashes.
- Identify: mist between panes (unit failure) versus water on cill/draughts (frame or hardware).
- Call a reputable repairer, share photos, and get clear options.
- Keep receipts and communicate with your insurer promptly.
Storms test windows. The right response protects your home, keeps energy bills sensible, and avoids throwing money at the wrong fix. Treat your double glazing as a system: glass, frame, and hardware. Address the weak link with proportionate work, and it will see you through the next season with fewer rattles, no drips, and clearer mornings.