Hi, I'm a keen DIY'er and am looking at building myself a gym in my back garden, its going to be a wooden construction and ive tried to find out as much as I can about the construction from watching you tube videos and reading different bits and bobs. I have 2 areas where I'm not 100% sure as what to do for the best, the first is with the roof construction, I want to have it as tall as poss so aim to go to 3m tall (as I believe that's my limit without planning permission - correct me if I'm wrong) but I don't want trusses inside from wall to wall limiting my height inside, so was going to go for a big long beam from end wall to end wall but was unsure if that's strong enough? How should I strengthen the end walls so they can deal with the extra weight? whats the best size would to use 2x6? 2x8 or 2x10??? As you can probably tell I don't know all the correct terminology, but any helpful info or websites to help me with this would be great thanks. Also the base, I'm going to go for a concrete base, to prevent the bottom wood from rotting out over time do I make the base the same size as the building and have it raised? OR do I have it bigger then the building and lay a course of bricks to raise it off the ground? Is there any advantages for on over the other or are both fine? Any other help on the right ways (and wrong ways) to help with my plans would be great thanks. Cheers )