Taped joints are the structural seams where plasterboard sheets meet. When these joints are correctly taped and "filled," they create a seamless, flat surface r...
Repairing these joints is about more than just aesthetics; it ensures the structural integrity of your internal walls and prevents further cracking. For UK homeowners, addressing failed joints early prevents the need for a full, costly re-skimming of the entire room.
What Does the Work Involve?
- Assessment: Identifying if the crack is a simple tape failure or a sign of deeper structural movement.
- Removal: Carefully cutting away loose tape and scraping out old, crumbled jointing compound.
- Preparation: Sanding the area back to the board and applying a PVA sealer if the board core is exposed.
- Re-taping: Applying new glass-fibre scrim tape or paper tape across the seam.
- Bedding & Filling: Applying multiple "feathers" of jointing compound, with each layer wider than the last to mask the bump.
- Sanding: Using fine-grit sandpaper (usually 120 or 180 grit) to create a flush, invisible finish.
- Mist Coating: Applying a thinned layer of paint to seal the new compound before final decoration.
Typical Costs
| Item | Low £ | High £ | Notes |
|---|---|---|---|
| Call-out / Minimum Charge | £80 | £150 | Covers travel and first hour of labour. |
| Small Repair (1-2 joints) | £120 | £200 | Includes materials and basic sanding. |
| Full Room Re-tape | £350 | £600 | Standard 4x4m room; excludes painting. |
| Ceiling Joint Repairs | £200 | £400 | Higher cost due to working at height. |
| Materials (Tape & Compound) | £15 | £40 | Per room basis. |
Prices vary depending on your location in the UK, with London and the South East typically seeing rates 20-30% higher. The complexity of the repair—such as working around intricate coving or at height on stairwells—will also increase the final quote.
How Long Does It Take?
- Minor Patch Repair: 1–2 hours (plus drying time between coats).
- Single Wall Re-taping: 3–5 hours across two visits.
- Full Room (Walls & Ceiling): 1–2 days of active work.
- Drying Time: 12–24 hours per coat, depending on humidity and ventilation.
DIY or Professional?
While small cracks can be tackled by a confident DIYer, achieving an "invisible" finish is notoriously difficult. Professionals use a technique called "feathering" to spread the compound over a wide area, which prevents the hump from being visible when the light hits the wall.
If your joints are failing because of significant structural movement or damp, a DIY fix will only be a temporary sticking plaster. A professional plasterer can identify the root cause before repairing.
Choosing the Right Tradesperson
- Check Credentials: Look for City & Guilds or NVQ Level 2/3 in Plastering.
- Dust Management: Ask if they use "dustless" sanding equipment or how they plan to protect your carpets and furniture.
- References: Ask to see photos of finished, painted joints; a bad repair only shows up once the paint is on.
- Questions to Ask:
- Do you use paper tape or adhesive scrim tape? (Paper is often stronger for internal corners).
- How many coats of compound will you apply?
- Is the final sanding and "mist coat" included in the price?
UK Regulations
- Part L (Thermal Efficiency): If you are removing large sections of plasterboard on an external wall, you may need to ensure the repair meets current insulation standards.
- Fire Safety: In flats or multi-storey homes, taped joints in "fire-rated" boards must be repaired using fire-resistant compounds to maintain the integrity of the fire barrier.
- Health and Safety: Professionals should follow HSE guidelines regarding silica dust inhalation during the sanding process.
Common Problems
- Visible Humps: Caused by not feathering the compound out wide enough from the joint.
- Tape Lifting: Occurs when the compound underneath the tape dries too quickly or wasn't applied generously enough.
- Blistering: Air bubbles trapped under paper tape, usually due to poor application technique.
- Flash Cracking: Small cracks appearing in the new compound because the room was too hot or draughty during drying.
Frequently Asked Questions
Why do my taped joints keep cracking?
This is usually due to seasonal movement (timber shrinking or expanding) or "vibration" if the wall is near a heavy door. If the boards weren't screwed tightly to the studs originally, the movement will repeatedly break the tape.
Should I use mesh (scrim) tape or paper tape?
Mesh tape is easier for DIYers as it is self-adhesive, but paper tape is generally considered stronger and less likely to crack in the long term, especially in internal corners.
Can I paint over the repair immediately?
No. You must wait for the compound to turn from grey/pink to a uniform white. You then need to apply a "mist coat" (diluted emulsion) so the dry compound doesn't suck the moisture out of your topcoat too quickly.
Is the dust dangerous?
Plasterboard and jointing compound dust can be an irritant. Professionals use HEPA-filtered vacuums attached to their sanders to minimise mess and health risks.
How do I know if it's a tape failure or a structural crack?
Tape failure usually follows a perfectly straight vertical or horizontal line (the edge of the board). Structural cracks are often diagonal and may be wider than 3mm; these require a structural engineer rather than a plasterer.
This guide was written with AI assistance and is intended for general information only. Prices are estimates based on UK averages and may vary by region. Always get at least three quotes and consult a qualified professional before starting any work.
