How do I avoid making costly mistakes when doing DIY on my home?

Checkatrade’s Kevin Byrne looks at the most common blunders people make when tackling renovation jobs, and offers tips on how to deal with them

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When it comes to house renovations, tackling some of the work yourself can be a good way to cut costs, putting the money saved towards jobs that require a professional's expertise.

But a mix of over-enthusiasm and inexperience can lead to mistakes that cost more to put right than you were attempting to save. According to a recent survey, carried out by, 77 per cent of people in the UK admit to making expensive blunders while tackling DIY. Here are the most common:  

72% have run out of materials part way through a job

‘Every DIYer will run out of things mid-job because they are more likely to buy the amount they think they need and no more, and it is often not enough,’ says Kevin Byrne of Checkatrade

‘Where they need to be careful is if something requires setting. Running out of plaster or cement and having to go off site to get more means you might not end up with as good a finish as you hoped for. You’re much better off buying more than you think you need and returning any extra.’

how to avoid diy mistakes

(Image: © real homes)

63% have measured up inaccurately

‘The first thing that comes to mind is the adage measure twice, cut once. Measure it, write it down, then measure it again and tick off that it’s right. Most people do DIY in the evenings or the weekends when the builders’ merchants are closed. If you cut a piece of wood the wrong size, you have to stop and wait for the shops to open. It just slows everything down.   

61% have damaged carpets and furnishings

‘If you don’t want paint on something, cover it up or remove it from the room. If you have got gloss paint on a carpet, in my view you’ve got to rip it out and throw it away. A specialist could try to patch it if you have some old off-cuts, but you will always see it. If you do spill emulsion, phone a carpet cleaner and ask for advice. Then get a spoon to carefully scoop as much up as you can. Put a bit of water on and keep using the spoon to scoop it up. Don’t spread or rub it in. Don’t let it go dry, try and keep it moist until the carpet cleaner arrives. 

'If you spill something like turps or white spirit, mop it up with something absorbent and try and get as much out as you can. You will probably have to live with the smell for a while, though.’ 

52% have used the wrong paint  

‘If you’re not sure what to use, ask the staff of wherever you are buying the paint from to help you. Most formulations are pretty obvious, but if you are doing a job that’s more specialist, like putting lacquer on an oak staircase, you want to make sure you have the right product. Where a lot of people do go wrong is in sealing surfaces. 

'If your house is rendered and you are going to paint it, you need to seal it first. A lot of DIYers think they can use watered-down PVA glue. But what that does is prevent any paint you put on the house from sticking to it. After less than a year the paint will bubble and come off the wall. That type of mistake can be a nightmare to put right.’ 

28% failed to obtain the correct permits

‘If you’re not sure if you need a permit for the work you want to do, or what sort you need, go to a site like This has planning and building regulations information, and can advise on what permissions you need for home-improvement projects. Your local council will also have householder surgeries where they offer pre-application planning advice. 

‘When it comes to something like skip hire, if it has to go on the road, the firm will tell you what permits are needed.’

how to avoid costly mistakes while doing DIY

(Image: © real homes)

51% failed to prepare the surface they were painting

Project Pete, the DIY expert from B&Q, reveals how to properly ready your surfaces 

When painting a room:

Clean walls, skirting boards, door and window frames, and all remaining fixtures using a diluted solution of sugar soap and a large sponge, working the mixture into the surface. Wipe the surfaces clean using a sponge or cloth. Try not to drip water down the wall and onto the floor.

If there are cracks in the plaster, rake any loose plaster out with the corner of a filling knife or scraper. Using a small paintbrush, dampen the crack with water to encourage the new filler to dry slowly and stop it shrinking and falling out. Load some filler onto a filling knife and draw it across the hole at right angles to the crack, firmly pressing it in until the filler is raised just above the surface of the wall. Leave to dry, then smooth with 80-grit sandpaper wrapped around a sanding block. 

Wrap a fresh piece of 80-grit sandpaper around a sanding block and gently sand all the surfaces in the room, using a circular motion to cover all areas. Dust and vacuum everywhere, from ceiling to floor. Lay dust sheets across the floor or tape polythene dust sheets in place with masking tape. Cover switches and sockets with the tape to protect them. If you’re not painting skirting boards and door trims, mask these off. 

If you’re applying more than one coat of paint, it’s a good idea to remove and reapply any masking tape between coats. As the paint dries and joins to the tape, it can pull off the paint as the layers build. To combat this, remove the masking tape slowly at a 90-degree angle before the paint fully cures. 

Loosen the canopy or trim piece of ceiling lights without exposing the wires beneath, so you can paint under the fitting rather than around it. 

When painting wooden window frames:

Remove catches and stays from the window frame before you start. If you’re going to fit new window furniture after you’ve repainted, fill the old holes with wood filler and sand them down with fine-grade sandpaper. Lightly sand over the old paintwork using medium-grade sandpaper then brush away any dust and debris. 

If you don’t have a steady hand, use a paint shield or cut some masking tape to fit around each pane of glass. Set the tape 2mm in from the frame so the paint will just overlap onto the glass and seal out water. Use a combined primer/
undercoat to paint the frame. To make the job easier, use a cutting-in brush for the glazing bars. Apply a top coat, then use a varnish, such as B&Q Gloss interior Varnish, for a perfect finish.

how to avoid costly mistakes while doing DIY

(Image: © real homes)

59% have injured themselves doing DIY

Accidents can often occur while doing DIY – Mike Evans, of DjB Training & Development, reveals how to prevent them and what to do if they happen  

1. Accidents happen more easily when you are unprepared and in a rush, so think through the tasks and prepare yourself properly before you start.

2. Read the instructions for how to use tools or products, and stop and disconnect all electrical appliances and tools before repairing/cleaning them.

3. Avoid falls from height by checking a ladder’s condition before use.

4. Keep children and pets away from where you are working, and make sure tools, paint and chemicals are out of their reach.

5. Store products in their original containers, and always tidy up at the end of your task.  

Slips, trips or falls, these can cause broken bones and head injuries. If broken bones are suspected, get help. Phone for an ambulance immediately and tell them what has happened. 

Contamination by solvents, corrosive and poisonous substances can be prevented by using the correct tools and by wearing appropriate protective clothing. Check any manufacturer’s special handling, decontamination and first aid advice before starting work, and never decant hazardous substances into unsuitable/unmarked containers.

If someone does spill a corrosive substance onto themselves, it should be dealt with according to the manufacturer’s guidelines on the container. If unsure, run cool tap water continuously over the contaminated area. Carefully remove any contaminated clothing, taking care not to spread it. Call the emergency services and keep samples of the substance or container involved for their information.

19% have given themselves an electric shock

A competent, qualified person should always carry out gas and electrical renewal or repair work. In the case of gas work, in the UK, they must be registered through the Gas Safe Register.  

Always read and understand the instructions before using tools. When working with power tools, use a residual current device (RCD) if your home isn’t already wired with one. Contact with electricity during DIY, maintenance or gardening can cause burns and cardiac arrest.  

In all cases of electric shock, isolate the power at the mains switch before approaching the casualty. If they are conscious, they will be breathing. They may have a burn wound at the point of contact, possibly with an exit wound as it goes to earth. Irrigate the burn by running tepid tap water over it for 10 minutes, if the burning sensation remains, keep repeating. If there’s no pain at the start and there is a large burn, irrigate continuously until relieved by paramedics. If the casualty is unconscious, phone for an ambulance and follow the advice of the dispatcher.