Mfoster

Hi All My first post here, hope you're all well Just after some advice pls. I'm preparing a base for a wooden (cedar cladded) insulated garden room (4.2 m by 3.02 m) So far we have cleaned and levelled the area and put down 4 inches of Mot, we plan to put down a 4 inch concrete base However I'm getting mixed reports and opinions from tradesman / friends etc.. that 4 inches is either enough or its not enough and I should go for a 6 inch with re-bar The room will contain me, a small sofa, desk, some music equipment, you know typical man cave / office type set up Not being an expert in this areas you can imagine I'm a bit undecided and worried I'll make the wrong decision. I just wondered if anyone has done a similar project and if a 4 or 6 inch base is best etc..? Many thanks in advance :)