I'm building a relatively small low level deck that should be able to take a heavy load. It's between two garages and a bit of an odd shape. I've already fitted two ledgers and I've dug holes for the posts. The post holes are 700mm deep with a concrete block at the bottom. My plan was to sit a 100x100 treated post on the concrete block using additional stone / brick to fill some of the space and use postcrete to fill the hole. I've then been reading that concrete can wick the moisture out of the surrounding earth and eventually rot the timber even if it's treated. I don't want to have to replace all the posts in 10/15 years time... I've seen one option to use a cardboard former and pour a concrete footing I can then secure the post using a galvanised / stainless steel fitting... Secondly, most examples I've seen secure joists to the side of the posts using coach bolts, I've however seen some people either notch the post (could cause a pocket for rot) or sit the joists ontop of the posts so as to avoid a 'shear point' on the bolts and better spread the weight. Opinions??