Hi all! I hope this is the right area of the forum. I am building a pergola and decking over a concrete slab and I’m using post bolt downs anchored with throughbolts into the concrete. there’s two thinks bugging me I’m hoping you guys might have some advice on? 1) the first is other than the holes in the post bolt down dictating what size M8/10/12 etc to go with how do I determine the length of bolts to buy? It’s for a 2.5ish m high 150x150mm post. I know they all have recommended embedment depths which I understand, but how do I know if I should go for a m12 95mm or a m12 180mm for example? Is there a calculation to the the correct length? 2) the second thing on my mind is what is the best way to get the post bold downs level and therefore the posts plum? It was ‘unofficially’ suggested that I could put a few washers under bolts to shim up a side that’s low and get it level but if there a best practice for this? thanks very much for any comments!