Replacing a sealed unit typically costs £150–£250 and is often cheaper than a full window replacement
If a double glazed window has misted up or the seal has failed, you may be considering a full replacement. However, replacing just the sealed unit (the glass panes inside the frame) is usually the more cost-effective option. The Glass and Glazing Federation (GGF) estimates that replacing a sealed unit costs between £150 and £250 for a standard-sized uPVC window, including labour (GGF, 2026).
Removing double glazing beading costs £150–£250 for a sealed unit replacement, or £5–£15 for a replacement length if damaged. Clip-in beading requires a glazing bead removal tool; screw-fixed needs a screwdriver. DIY removal saves £40–£80 on labour.
- Replacing a sealed unit costs £150–£250, often cheaper than full window replacement.
- Removing beading yourself saves £40–£80 on labour costs.
- Clip-in beading needs a glazing bead removal tool, not a screwdriver.
- Screw-fixed beading requires a screwdriver or drill for removal.
- Damaged beading replacement costs £5–£15 from DIY retailers like Screwfix.
- Replacing a sealed unit typically costs £150–£250 and is often cheaper than a full window replacement
- The two main beading types are clip-in (dry glazed) and screw-fixed (wet glazed), and each requires a different removal method
- The correct removal tool for clip-in beading is a glazing bead removal tool or a wide putty knife, never a screwdriver
- Quick numbers, typical removal time, tool cost, and success rate
- Removing double glazing beading is a DIY task suitable for most homeowners, provided the sealed unit is already broken
- To verify a double glazing installer for replacement work, check they are FENSA or CERTASS registered and hold MCS certification if using energy-efficient glass
- The plastic beading on uPVC windows is almost always clip-in, but you should confirm by looking for screw caps or a visible screw head
- If the beading is stuck, do not force it, apply gentle heat from a hairdryer to soften the uPVC before attempting removal
Labour for removing and refitting the beading, the plastic or wooden strips that hold the unit in place, is typically included in that price. If you remove the beading yourself, you could save £40–£80 on the total bill, depending on your location and the installer’s rate. The final cost varies by window size, the type of beading (clip-in vs screw-fixed), and regional labour rates. If the beading is damaged during removal, a replacement length costs roughly £5–£15 from most DIY retailers (Screwfix, 2026).
The two main beading types are clip-in (dry glazed) and screw-fixed (wet glazed), and each requires a different removal method
Clip-in beading, also called dry glazed, is held by spring clips that push into the frame. This type is common on uPVC windows installed after 2005 (GGF technical guidance, 2026). Screw-fixed beading, or wet glazed, uses screws driven through the beading into the frame. It is often found on older uPVC windows and timber windows. Clip-in beading is usually removable without power tools, while screw-fixed requires a screwdriver or drill. The British Fenestration Rating Council (BFRC) notes that identifying the correct type is essential to avoid damaging the frame or the beading (BFRC, 2026).
The correct removal tool for clip-in beading is a glazing bead removal tool or a wide putty knife, never a screwdriver
Using a screwdriver to pry off clip-in beading is a common mistake. The narrow blade can gouge the beading and the frame, making refitting impossible without new parts. The GGF recommends a dedicated glazing bead removal tool or a wide putty knife (GGF technical note, 2026). Insert the tool at the midpoint of a long side, twist gently to pop the clip, then work along the bead. Starting at a corner can crack the beading because the clips are strongest there. Work methodically around the window, removing the top bead first, then the sides, and finally the bottom bead.
Quick numbers, typical removal time, tool cost, and success rate
| Item | Typical value |
|---|---|
| Time to remove clip-in beading (one window) | 10–20 minutes |
| Time to remove screw-fixed beading (one window) | 15–30 minutes |
| Cost of a beading removal tool | £8–£15 |
| Cost of replacement beading per metre | £3–£8 |
| Typical success rate (beading reusable) | 70–90% for clip-in; 50–70% for screw-fixed |
Time estimates are based on a 2026 Which? guide to window maintenance (Which?, 2026). Tool costs are from Screwfix and Toolstation as of 2026 (Toolstation, 2026). Success rates assume careful removal; damaged beading will need replacement.
Removing double glazing beading is a DIY task suitable for most homeowners, provided the sealed unit is already broken
If your double glazed unit is misted or the seal has failed, removing the beading to replace the unit is a straightforward DIY job. The core steps are: identify the beading type (clip-in or screw-fixed), choose the correct tool (bead removal tool or screwdriver), remove the beads in order (top first, then sides, then bottom), and lift out the sealed unit. The GGF consumer guide on sealed unit replacement confirms this sequence (GGF, 2026). However, if the sealed unit is still intact and airtight, removal is not recommended unless you are replacing the unit anyway. Breaking the seal will cause immediate condensation, rendering the window unusable until replaced.
To verify a double glazing installer for replacement work, check they are FENSA or CERTASS registered and hold MCS certification if using energy-efficient glass
Building Regulations in England and Wales require that replacement glazing is installed by a FENSA or CERTASS registered installer (GOV.UK, 2026). These schemes ensure the work meets thermal performance and safety standards. If the replacement is part of a heat-pump or solar installation, the installer must also hold MCS certification for the full system to qualify for government grants (MCS register, 2026). Always check the register at fensa.org.uk or certass.co.uk before hiring. Guide to finding a certified window installer
The plastic beading on uPVC windows is almost always clip-in, but you should confirm by looking for screw caps or a visible screw head
To identify the beading type on a uPVC window, run your finger along the beading. If you feel a small bump every 20–30 cm, that is a screw cap covering a screw head. If you see no caps and the beading feels smooth, it is likely clip-in. The GGF technical bulletin on uPVC window bead identification notes that some manufacturers use a hybrid system with clips and one or two screws in the corners (GGF, 2026). Check all four sides carefully before starting.
If the beading is stuck, do not force it, apply gentle heat from a hairdryer to soften the uPVC before attempting removal
Temperature changes can cause uPVC to expand, gripping the clips tighter. If the beading feels stuck, apply gentle heat from a hairdryer set to a low or medium setting. Heating the beading to around 40°C (warm to the touch) for 30 seconds is usually enough to release the grip. The GGF guidance on uPVC window repair cautions that excessive heat above 60°C can warp the beading or damage the seal (GGF, 2026). Never use a heat gun or open flame, as this will damage the uPVC. How to repair uPVC window frames
Frequently Asked Questions
Use a glazing bead removal tool or wide putty knife for clip-in beading. For screw-fixed beading, remove screws first. The Glass and Glazing Federation (GGF) warns against using a screwdriver as it can gouge the frame.
Yes, you can replace beading yourself. Clip-in beading is easier and requires no power tools. Screw-fixed beading needs a screwdriver. Replacing a damaged length costs £5–£15 from Screwfix, according to their 2026 pricing.
Clip-in beading uses spring clips and is common on uPVC windows after 2005. Screw-fixed beading has screws driven into the frame, found on older uPVC and timber windows. The GGF technical guidance (2026) explains both types.
Replacing a sealed unit costs £150–£250 for a standard uPVC window, including labour. The Glass and Glazing Federation (GGF) provides this estimate for 2026. DIY removal of beading saves £40–£80.
For clip-in beading, use a glazing bead removal tool or wide putty knife. For screw-fixed beading, use a screwdriver or drill. The British Fenestration Rating Council (BFRC) advises against using a screwdriver for clip-in types.
