Nick Knowles: My DIY golden rules – and when to let the professionals take over

My friend Chris, a brilliant plasterer who I’ve been working with for the last 26 years, recently went to a big, Georgian home to price up a job. The homeowner, a surgeon, said to him: “The entire place needs replastering. But what I’d like to do is pay you to come and plaster the living room. I’ll watch you for the day and then I can do the rest of the house.” Chris said: “Ok. And when you operate next, shall I come, watch and then do the rest of your surgeries for that week?” Shorts When it comes to home renovations, for some reason we think we can do it all ourselves. A quick YouTube video and a visit to the local DIY shop and we’re ready to tackle anything, suddenly convinced that we’re qualified plumbers, plasterers and electricians. But getting it wrong can lead to costly mistakes – and paying a professional more to fix your botch job and do the work again could cost you thousands more. There is a reason why tradespeople spend two years or more in apprenticeships learning their craft: it’s not easy. When Chris was training, he was only allowed to plaster the inside of cupboards and under the stairs. You practise in the places where no one can see, until you get it perfect. Tradespeople don’t just have the knowledge and skills to do the job; they have the tools for it too. Most will turn up with four-and-a-half grand’s worth of kit, which they have spent years building up. You, on the other hand, will pop to B&Q and buy a cheap drill and router. They’ll be the wrong tools for the job and will cut ragged, and you won’t know the tricks of the trade to tidy it all up. When it comes to renovations, yes, you could do it yourself – but it’s never really a good idea. You want to try plastering your own home? You’re working with basically a fluid mineral mix that you are trying to apply evenly on a vertical surface. Let me tell you, when you try that for the first time, 80 per cent will end up on the floor and on your shoes. These are real skills and we don’t value them enough. You wouldn’t attempt to fly a plane or remove your own appendix, so why do you suddenly think you can do your own electrics? I’ve seen plenty of instances of home renovation attempts gone wrong on DIY SOS. There are basic rules that amateurs might not know: cable from a light switch should go directly upwards, and from a plug socket should go directly down, for example. I’ve seen cables running through walls at all sorts of angles and instances where someone has rewired their home and run out of cable, so decided to use the cord from an old extension lead to finish the job. When you’re putting in screws, have you checked where your water pipes, gas pipes and electrical cables are going? Have you thought about what’s holding up the rest of the chimney before you take a sledgehammer to the fireplace? I’ve seen homes where a family member has put the central heating in and the whole thing has basically had to be condemned. In one old property, we took the plaster off the wall and discovered it was filled up with old turnips instead of insulation! And then there’s the very serious. Like the time someone had built an extension without doing any sort of survey and crushed the drain under their own home. Then they wondered why they were getting damp and black mould. That one cost at least £10,000 to put right. So, what tasks can you get involved in? You could try painting and decorating, hanging wallpaper or tiling (although in my opinion, a professional will still do a much better job in a quarter of the time it will take you). You can do some of the prep work before the tradesperson comes in, like taking the old plaster off the wall if it’s already starting to fall. Do the interior design if you’ve got an eye for it or know someone who does. With any DIY job, do your research first. Watch videos, try and practice, and use tricks to try and get a professional look. Builder’s caulk on a skirting board, for example, will give you a perfect finish. But know your limits. If you’re a teacher, or a doctor, or whatever – go and be good at that, and save up enough money to pay someone who’s a really good chippy, plasterer or tiler. Don’t go and buy a load of cheap tools that you’ll use once and aren’t fit for the job anyway. You might think you’re going to get satisfaction out of doing it yourself, but you’ll probably get more satisfaction going to the pub for a pint while someone skilful does the job better than you ever could. Sometimes it really is better to call in the professionals.