Misted double glazing repair in Teesside

Misted or cloudy double glazing means the sealed glass unit has failed, not the window. Replacing just the unit costs £80–£150 for standard sizes (£150–£250 for large or bay units), keeps your existing frames, and typically takes under an hour per window.

From £80 per unit

Why double glazing mists up

A double glazed unit is two panes factory-sealed around a spacer bar filled with desiccant. When the perimeter seal fails, age, UV, frame movement, or a cheap unit to begin with, moist air gets in, the desiccant saturates, and condensation fogs between the panes where no cloth can reach it. On Teesside the failure wave is predictable: estates glazed in the late 1990s and 2000s (Billingham, Thornaby, Ingleby Barwick especially) are hitting seal-failure age together, and coastal exposure in Redcar accelerates it.

The fix: swap the unit, keep the frame

The specialist measures the failed unit (thickness matters, 24mm and 28mm are the common Teesside specs), has an identical sealed unit made, and swaps it into your existing frame. Beads out, old unit out, new unit in, beads back: typically 30–60 minutes per window, no scaffolding for ground floors, no making-good, no redecoration. The glass comes new with a manufacturer warranty, typically 5–10 years against seal failure.

What it costs

Sealed unit replacement, Teesside (2026)
UnitTypical priceNotes
Standard unit (up to ~1m²)£80–£150Most bedroom and lounge windows
Large or bay unit£150–£250Bay bows, patio door panes
Specialist glass+£30–£80Toughened, laminated, acoustic or patterned
Multi-unit discount~15–25% off3+ units in one visit is the norm

Compare that to £400–£700 for a whole new window and you see why unit replacement is the busiest corner of the trade. Our full cost guide breaks the pricing down further, including when a failed unit is actually telling you the frame's done too.

Upgrading while you're at it

A unit swap is also a cheap upgrade opportunity: modern low-e argon-filled units insulate noticeably better than 20-year-old glass, and acoustic laminated units calm main-road rooms. Both go into the same frames for a modest premium, worth asking about when you get quotes.

Frequently asked questions

Can misted double glazing be repaired, or does the unit need replacing?
The unit gets replaced, claims of 'demisting' drilled-hole repairs are a false economy that voids the thermal seal. A new sealed unit is £80–£150 and carries a 5–10 year warranty.
How long does a new sealed unit last?
Quality units are warrantied for 5–10 years and typically last 15–25. Premature failure usually traces to poor drainage in the frame or movement, a good fitter checks both while swapping the unit.
My frames are 20 years old, is it worth just doing the glass?
Usually yes if the frames are square, draught-free and mechanically sound. If gaskets are perished and hardware's failing across the house, that's the point a full replacement conversation starts making sense, our repair vs replace guide walks the decision.

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