The problem with spray systems is the fine balance between the amount of time needed to mask off woodwork etc. before work begins and the actual time saved spraying the walls. You’ll need to thin the paint according to the maker’s instructions. Most need a lot of preparation to get the paint and water correctly mixed plus even more cleaning up time.

The Bosch PFS 65 delivers good DIY results. But the paint reservoir is small and the unit won’t have enough power to cope with your scale of project. It might be better to hire a large volume turbine spray. They have the paint pot fitted to a floor standing power unit so it’s less tiring to hold and needs fewer refills. You also get a long (5-6m) air line so you can walk around the room without having to move equipment. HSS can supply these – to find your local branch visit www.hss.com.