Harlow · Essex
Misted Glass Repair in Harlow
Clear glass again in Harlow: replacing blown double glazing units restores the view and a sealed cavity while your existing frames stay in place.
- CM17
- CM18
- CM19
- CM20
- Guide from £155
Blown double glazing units for homes and businesses in Harlow
Once the seal has failed, any argon or other insulating gas in the cavity has escaped and been replaced by ordinary damp air. The unit insulates less well than when it was new, and moisture inside can gradually leave deposits that dull the glass.
A sealed unit has a spacer bar around its edge filled with desiccant, a drying agent that absorbs any moisture inside the cavity. When the edge seal fails, damp air keeps getting in until the desiccant is saturated, and condensation then forms between the panes where it cannot be wiped off.
Early seal failure often shows only on cold mornings or after rain and clears during the day. As the desiccant fills, the mist lasts longer and white mineral staining can form on the inner faces. Staining inside the unit cannot be removed by cleaning from either side.
Replacing a misted unit is usually a short job per window once the new unit has been made. The old unit is lifted out, the frame rebate and drainage cleaned, and the new unit set on packers so the weight is supported and any opening sash stays square.
What's included
- Written quote fixing the price for the specification
- Made-to-measure replacement units matching your windows
- Fitting on packers with drainage slots checked
- Measurement of each failed sealed unit
Local details for Harlow
- Postcodes covered
- CM17, CM18, CM19, CM20 and the surrounding area, including Hoddesdon, Bishops Stortford and Waltham Abbey
- Coast
- Harlow is well inland, around 38 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Harlow the midwinter sun reaches about 15° above the horizon at noon, with roughly 7.5 hours of daylight, rising to about 62° and 16.5 hours in midsummer. Units on sunny south and west elevations go through bigger daily temperature swings, which stresses the edge seal over time. In colder, darker months, mist between the panes is often most visible, so the survey is a good time to confirm failure.
- Access and setting
- In flats and terraced streets, replacing misted units often means planning access, parking and carrying units up stairs. Upper-floor windows may need to be done from inside, and conservation areas may require matching bars or glass patterns.
- Rules in England
- Approved Document K requires safety glass in critical locations in England: glazing in doors and in side panels within 300 mm of a door, up to 1500 mm above floor level, and any glazing in walls or partitions up to 800 mm above floor level.
Guide prices in Harlow
| Typical job | Guide price inc VAT |
|---|---|
| One misted unit, 600 × 900 mm | £155 – £195 |
| Two misted units, 600 × 900 mm | £305 – £395 |
| Four misted units, 600 × 1100 mm | £685 – £875 |
| Misted unit in a door, toughened | £305 – £385 |
Get a guide price for your size
Approved Document L sets the minimum energy performance for replacement windows and doors in existing homes in England: a U-value of 1.4 W/m²K, or Window Energy Rating band B for windows; doors can instead meet a Door Set Energy Rating (band B, or band C for doors more than 60% glazed); rooflights need 2.2 W/m²K.
What you can choose
Georgian bar or leaded
Decorative bars or lead designs remade to match the originals so the new unit lines up with neighbouring windows.
Obscure glass unit
Patterned glass for bathrooms, landings and front doors, chosen to match existing obscure panes or to add privacy.
Low-E upgrade unit
A coated pane and gas-filled cavity that reduce heat loss compared with older plain glass units, fitted in the same frame.
Misted Glass Repair in Harlow: questions
Does misted double glazing lose heat?
A misted unit usually insulates less well than when it was new, because any insulating gas in the cavity has escaped and been replaced with damp air. The mist itself also reduces clarity. Replacing the unit restores a sealed cavity, and choosing a low-E unit can improve on the original performance where the old unit was plain glass.
Is it worth replacing misted units or should I get new windows?
If the frames are sound, square and the hinges and locks work, replacing only the misted units is usually the more economical option. New windows make more sense if the frames are rotten, warped, draughty or hard to open. The glazier checks the frames at the survey and the quote will say if replacing units is not good value.
Are misted units covered by a guarantee?
Often they are, for a period after installation. Many sealed unit manufacturers guarantee against misting, and the terms are set out in the paperwork from the original installer. If your units are still covered, contact that installer first. Units we supply carry manufacturer guarantees, and the terms are confirmed in writing with your quote.
How much does it cost to replace a misted sealed unit?
The cost depends on the size of the unit, the glass type, any Georgian bars, leaded or obscure features, how many units are done together, and access to the window. Larger units, safety glass and upper-floor windows cost more. See the guide prices for typical sizes, then get a written quote for your exact windows.
Do you cover Harlow for misted glass repair?
Yes. We can quote for misted glass repair across Harlow and the surrounding Essex area, including postcode districts CM17, CM18, CM19 and CM20, and nearby Hoddesdon, Bishops Stortford and Waltham Abbey. Start with your postcode on the quote form and a glazier will arrange a free survey before giving you a written quote.
Get a written quote in Harlow
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.