Borehamwood · Hertfordshire
Misted Glass Repair in Borehamwood
We cover Borehamwood and Hertfordshire for misted double glazing repair, replacing blown sealed units in uPVC, aluminium, timber and composite frames.
- WD6
- Guide from £155
Misted window repair in Borehamwood
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.
Check the paperwork for your windows before booking. Many sealed units come with a manufacturer guarantee against misting, and if your windows are still covered, the original installer or manufacturer may be responsible for replacing the failed unit under its terms.
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.
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.
Included as standard
- Written quote fixing the price for the specification
- Measurement of each failed sealed unit
- Made-to-measure replacement units matching your windows
- Survey to confirm the mist is inside the unit

Local details for Borehamwood
- Postcodes covered
- WD6 and the surrounding area, including Barnet, Bushey and Potters Bar
- Coast
- Borehamwood is well inland, around 50 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Borehamwood the midwinter sun reaches about 15° above the horizon at noon, with roughly 7.6 hours of daylight, rising to about 62° and 16.4 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
- Older rural homes may have timber frames or units of non-standard sizes, so careful measuring at the survey matters. Exposed sites with driving rain place more strain on seals, and the glazier checks frame drainage and bead condition before fitting.
- 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 Borehamwood
| 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.
Specification choices
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 Borehamwood: questions
Why has condensation appeared between my double glazing panes?
Condensation between the panes means the edge seal of the sealed unit has failed. Damp air has got into the cavity, and the drying agent in the spacer bar can no longer absorb it. The cause is often age, water sitting in the frame, poor packing or strong sun on the frame. The fix is to replace the sealed unit.
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.
Can you clean the inside of a misted double glazing unit?
Not without breaking the seal. Some firms drill the glass, flush the cavity and fit a small vent, which can clear the mist for a while. It does not restore an airtight seal or gas fill, and white staining may not fully clear. Replacing the unit is the reliable way to restore a clear, sealed cavity.
How long does it take to replace a misted unit?
There are usually two visits. The first is a survey to measure each unit. The second is fitting, once the new units have been made to order. Fitting usually takes a short time per window, with little mess. Your quote sets out when the units are expected, and we will tell you honestly when a glazier can attend.
Do you cover Borehamwood for misted glass repair?
Yes. We can quote for misted glass repair across Borehamwood and the surrounding Hertfordshire area, including postcode districts WD6, and nearby Barnet, Bushey and Potters Bar. Start with your postcode on the quote form and a glazier will arrange a free survey before giving you a written quote.
More glazing in Borehamwood
Misted Glass Repair nearby
Get a written quote in Borehamwood
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.