Ampthill · Bedfordshire
Misted Glass Repair in Ampthill
When condensation is trapped inside your glass in Ampthill, our glaziers can measure each failed unit and fit a matching replacement on a second visit.
- MK45
- Guide from £155
Blown double glazing units in Ampthill
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.
Once the seal has failed, any argon or other insulating gas in the cavity has escaped and been replaced by ordinary damp air.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.
The price of replacing misted units depends on the size of each unit, the glass specification, any bars or decorative features, how many units are done together, and access. Several units on one visit usually cost less each than separate visits for single windows.
Condensation on the room-side surface of the glass is not the same problem. It usually comes from humid indoor air meeting a cold pane and can be wiped away. Only mist trapped between the two panes means the sealed unit itself has failed and needs replacing.
What you get
- Fitting on packers with drainage slots checked
- Measurement of each failed sealed unit
- Survey to confirm the mist is inside the unit
- Removal of old units and cleaning of rebates

About Ampthill for this job
- Postcodes covered
- MK45 and the surrounding area, including Kempston, Bedford and Dunstable
- Coast
- Ampthill is well inland, around 87 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Ampthill the midwinter sun reaches about 14° above the horizon at noon, with roughly 7.5 hours of daylight, rising to about 61° 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
- 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 Ampthill
| 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.
Options to choose between
Like-for-like clear unit
A direct replacement matching the thickness and look of the original unit, for windows where no change in performance is needed.
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.
Toughened safety unit
Both panes toughened, for misted units in doors, beside doors or low down where safety glass is required.
Misted Glass Repair in Ampthill: questions
Will a new unit match my other windows?
It can. The glazier records the unit thickness, spacer bar colour, any Georgian bars or leaded designs, and the obscure glass pattern if there is one. Most details can be matched closely. If an obscure pattern has been discontinued, the quote offers the closest available alternative so you can decide before anything is ordered.
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.
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.
Can misted double glazing be fixed without replacing the window?
Yes. In most cases only the sealed unit needs replacing, not the frame. The glazier removes the beads, lifts out the misted unit and fits a new one made to the same thickness. Your frames, hinges, handles and locks stay as they are, provided they are in good condition, which the glazier checks at the survey.
Do you cover Ampthill for misted glass repair?
Yes. We can quote for misted glass repair across Ampthill and the surrounding Bedfordshire area, including postcode districts MK45, and nearby Kempston, Bedford and Dunstable. 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 Ampthill
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.