Advice · 4 min read · Updated 6 November 2026
10 common drylining mistakes and how to spot them
Why small faults matter
Drylining looks finished quickly, which makes it easy to hide shortcuts. Once walls are painted, problems such as hollow spots, cracked joints or missing fire board are much harder and more expensive to put right. Knowing what good work looks like helps you check before the decorator arrives.
Fixing and bonding mistakes
- Too few dabs on dot-and-dab walls, leaving boards that flex and sound hollow when tapped
- No continuous ribbon of adhesive around the board edges, openings and sockets, which lets air move behind the board and increases heat loss and noise
- Screws spaced too widely, driven too deep so they break the paper face, or not deep enough so they stand proud
- Boards fixed tight to the floor with no gap, so they wick up moisture
- Boards not staggered, so joints line up and form a weak continuous line
Board manufacturers publish fixing centres, typically screws no more than about 300 mm apart on walls and closer on ceilings. A competent dryliner follows these without needing to be asked.
Finishing mistakes
- Joints filled without tape, which crack along the board edges within months
- Too little drying time between coats of joint filler, causing shrinkage and visible lines
- Internal corners and external angles left without tape or angle bead
- Skim coats applied over boards with untaped joints
- Sanding through the paper face, leaving fluffy patches that show through paint
Check finished walls with a torch held flat against the surface. Raking light shows ridges, dips and joint lines that are invisible in normal light.
Specification mistakes
| Mistake | Why it matters |
|---|---|
| Standard board in a bathroom | Moisture can soften the board and encourage mould |
| Standard board where fire board was specified | The wall or ceiling may not achieve its fire rating |
| Acoustic wall with gaps or unsealed sockets | Sound leaks through the gaps and undoes the benefit |
| Insulated board without vapour control | Condensation can form behind the board |
| Plasterboard as a direct tile backer in a shower | Water can get in and the board can fail |
Preparation mistakes
The biggest preparation error is lining over a damp wall without finding the cause. The adhesive can fail, mould can grow behind the board and the problem returns in a worse state. Other common errors are fixing to loose old plaster, not allowing for the extra depth at window reveals and door linings, and boarding before the electrician and plumber have finished first fix.
Another frequent problem is boarding over old surfaces without checking them. Textured ceiling coatings applied before 2000 can contain asbestos and should be tested before they are drilled or sanded, and loose lath and plaster needs securing before it is overboarded. A little time spent checking the background prevents problems that only show months later.
How to check the work
- Tap the walls lightly with your knuckle and listen for large hollow areas
- Look along each wall from one end with a torch to check it is flat
- Check every joint and corner is taped and smooth
- Ask which boards were used in bathrooms, kitchens, escape routes and garages
- Check sockets and switches are tight and sealed on acoustic walls
- Ask for photos of insulation and vapour control before boarding
Raise any concerns before decorating starts. Most faults are quick to fix at this stage and much harder later.
Questions to ask before work starts
Most of these mistakes are avoided by agreeing the details in advance. A few direct questions also show whether the installer knows the work well.
- How many dabs per board, and will you run a continuous seal around the edges and sockets?
- What fixing centres will you use on walls and ceilings?
- Which boards will go in the bathroom, kitchen, garage and any escape routes?
- Will every joint and corner be taped?
- How will you deal with uneven or damp walls?
- How long should each stage dry before the next starts?
- Can you take photos of insulation, fire-stopping and pattresses before they are covered?
Good installers answer these without hesitation. Vague answers, or a reluctance to say which boards are being used, are a reason to ask more questions before booking.
It also helps to agree what finish standard you expect. Walls that will be lit by large windows or uplighters show every imperfection, so mention this so the level of finish can be planned and priced properly.
Frequently asked questions
Is it normal for dot-and-dab walls to sound hollow?
Some hollowness between dabs is normal, because there is a small gap behind the board. What is not normal is a board that flexes when pressed, or large areas that sound hollow across a whole board. That usually means too few dabs or poor contact with the wall. Tap the walls before decorating and point out any areas that move.
Why are the joints in my new plasterboard cracking?
The usual causes are joints filled without tape, too few fixings so the boards move, the building drying out and settling, or heating turned up too quickly after finishing. Fine hairline cracks in the first year can be normal settlement and are easily filled. Repeated or long straight cracks along board edges point to a fixing or taping fault.
Can poor drylining affect a fire or sound rating?
Yes. Fire-rated and acoustic walls only perform as tested if built exactly to the manufacturer's system, with the right boards, fixings, insulation, sealing and number of layers. Swapping a board type, missing a layer or leaving gaps can mean the wall falls short. Where ratings matter, ask the installer which system was used.
mistakes quality dot-and-dab snagging
Related services
We cover 250 towns and cities, including Peterborough, Bristol, Bath, Birmingham, Coventry, Nottingham.
