I'm relatively handy*, research and plan things deeply, and am somewhat detail oriented. But I've never worked with concrete or had to deal with things being underground or worry about water ingress or roof loads.We recently moved into our new custom-built passivhaus home in Minnesota. Time requirements and local laws basically meant I had to leave the building to the general contractor and only did the flooring and basement & garage electrical.Our home has a walkout basement. There is an inner corner area along side the home and at the back of the garage (Which is at '1st floor' level) where the dirt slopes up at a solid 30 degree angle to connect the back of the garage ground level with the walkout basement ground level. Image:https://ift.tt/2K42JoO like to dig out this area and put in a 728sqft (the largest I can do without needing city permission) flat-roofed set up for green roof, 'shed'. This shed would become my workshop so I can get out of the garage; I would heat it when I use it, but wouldn't heat/cool it when I wasn't using it. I'd keep 3-4 feet from my house/garage soas to not impact any footings through their. The door to the shed would be at the same level as my basement 'back' door.I'm struggling to find reputable information in how I would build such a thing, cheaply, and keep it dry.I'm finding *some* info on the foundation parts -- I've seen a lot of pros/cons for block vs poured concrete. Unfortunately, I don't think a concrete pump truck can get to this area (the site is heavily wooded all around and/or hills) .. but I'm not seeing a lot of "this is how you put a room underground and keep it dry and healthy". Most searches I'm doing keep running into 'prepper' people who have different priorities and generally are going entirely underground.I'm finding very little on how I'd build the roof (flat) and connect it correctly to the top of the walls.It would seem to me that I would need to dig it out, and ensure I put in a footing all around that's 4' below grade. On top of that, I think the cheapest and easiest DIY option would be start stacking cinder blocks (not filling the with concrete either). spray/paint on some dampproof materal, drop in crushed rock and some draintile, and the walls should keep it dry enough that it's not going to get water 'damage'. (it's a workshop after all... ) (though I see alternative ideas here)Put some joists on hangers inside the parapet walls, cover with plywood, tilt towards scuppers for good drainage via foam undrelayment stacking, put down EPMD and call it good.But this all seems like a lot of stuff outside my experience zone - concrete work, foundations, waterproofing, roofing, etc. Is this something a somewhat handy person can reasonably DIY... or is this something best left to the pros?*For example, I assisted my father as we built everything about our lake home (a contractor built the foundation and put up the exterior walls and roof but we did all the interior structural walls, windows, stairs, laid subfloor, electrical, hvac, flooring, tiling, trim, etc, etc, etc). I've converted, entirely on my own, a 1970 VW bug to electric. I've built plenty of furniture, 3D printing projects, basic metal work, etc as well as rewired my 1950s home's basement and built a home theater and bar in it. via /r/DIY https://ift.tt/2DmEe53
