Which DIY job should you have paid a professional for?

[WarpCore]

DIY can save money and bring a real sense of achievement. But every DIY enthusiast has at least one story of a job that went badly wrong. It might have taken five times longer than planned, cost more than hiring a professional or left a permanent reminder of the mistake somewhere in the house. These stories are funny in hindsight, even if they were not at the time

Common examples seem to be plastering, tiling, laying flooring and hanging wallpaper. They look simple on YouTube, but getting a smooth, professional finish takes real skill. Plumbing jobs can turn a small leak into a flooded kitchen, and anything involving gas or mains electrics should always go to a qualified professional anyway

My own disaster was plastering a small wall in the spare room. I watched three videos and felt confident. Two days, four bags of plaster and a lot of swearing later, the wall looked like the surface of the moon. I eventually paid a plasterer, who fixed it in an afternoon while trying very hard not to laugh. Experience is an expensive teacher

Please share your stories, both as warnings for others and for a bit of shared sympathy. If you learned a useful lesson, share that too. It might save someone from making the same mistake

Which DIY job should you have paid a professional for?