Home improvement projects can be exciting and rewarding, especially when you tackle them yourself. However, not all DIY jobs are created equal. While some tasks can be easily accomplished with a little research and effort, there are certain projects that could end up costing you thousands of dollars if not done correctly. We will highlight a few DIY jobs that require professional expertise and explain why it's crucial to hire a skilled contractor instead of attempting them on your own.

If your roof needs fixing, you should always hire a specialist roofer to do the job for you. Not only is it a dangerous job that requires experience, but it's one of the most expensive too.

Benjamin Heginbotham, director at The Practical Planning Company, says: 'The roof is a deal-breaker when it comes to selling your home. If you were looking at buying a house with a broken roof, it would be perfectly reasonable for you to ask for the value of a reroof

While tiling your own bathroom or kitchen might seem like a clever money-saving trick, it can cost you even more if it doesn't go to plan. Previous research found that only six percent have attempted their own tiling jobs, while 25 percent had to hire a professional tiler to repair their initial DIY efforts.

Tiling jobs that go wrong can cost big time, so it's also best to only do this if you really know what you're doing. If you've never done tiling or grouting before, it's difficult to get a good, polished end result. And as soon as someone comes in to view the house in the interest of buying it, they're going to want to redo the whole thing and will expect the asking price to come down.

While a badly painted room or choice of color can be easily fixed, it can affect your property value if you're looking to sell. Paint jobs are one of the most popular DIY projects, with 44 percent of people redecorating their own homes without the help of professionals. It might be a fairly simple task, but paint jobs that go wrong can cost thousands to fix.

Without a doubt, badly done DIY and individual paint colours such as bright orange have a distinct impact on the offer level for a home. As prospective buyers take into consideration the cost to re-do the DIY works and to change a colour.'

Not sure what colour to opt for? The study also found that cream-coloured kitchens, as well as dove light grey palettes in living rooms can sell more than properties with less desirable colour schemes.

Another DIY job that can cost thousands if done badly is plumbing. Research revealed that 55 percent had to call in the help of plumbers after their original job didn't go to plan.

While the cost to reinstall a leaking toilet a little bit pricey, it's much better to ask for help to begin with. It would still be safer for a professional plumber to do the job, which is much cheaper than attempting — and failing — yourself.

Open-plan kitchen and living areas create wonderful light-filled spaces, but they might not be adding any value to your home. While they certainly add more space, the research found that simply rearranging furniture to create the illusion of a bigger room can save you (the average price it costs to knock down an internal wall).

Some quick wins to give the illusion of a bigger room include using mirrors, clearing the clutter, and choosing with furniture on legs (see more advice from interior designer). Not only will this save you time but it will also save you, too.