Good Afternoon, I'm looking for someone to lead me in the right direction. I want to build a shed on an existing concrete slab in my back yard, the slab is 10'X16' and already has a power conduit with wiring in it from the previous shed. I want to build the first 4' of the shed walls using 8x8x16 concrete blocks and finish the other 4' using wood. Anyone ever build a shed this way? And can you give me some tips and tricks. I know how to lay brick and block but worried about the transition from block to wood. Any info would be helpful.

 

You might want to measure your pad carefully and make sure the sides are parallel and that it is square (meaning, when you measure the diagonals, those measurements are exactly the same).

That first step is important, because if the pad isn't square, you might want to compensate with your block walls a little, so as to square/true it up.

I would interject here that you should check with your local building department to ensure that a shed of that size can go on a pad. Because some areas have codes that once your shed reaches a certain size (sq ft), it needs to be on a footing (below frost) like any other permanent building would be.

You would usually want to figure out where your blocks will be going, and drill some holes for rebar in the pad, roughly within 12" of all 4 corners and within 12" of any/all door openings and roughly every 4ft thereafter. Then you will hammer the rebar into those holes... and drop your blocks over the rebar as you lay the walls up. Those cores will get grouted full with concrete, and will also be the places you will leave 1/2" j bolts sticking up 2 - 2 1/2" above the top course for your sill plates.

You will often want to make your finished masonry openings for doors and such 3" oversize so that you can put a treated wood buck inside them, to anchor your doors and jambs to.

Your 2X8 treated sill plate will lay down over the 1/2" j bolts, either flush to the outside of the block or 1/2" inset depending on how you want to do it (put foam sill sealer underneath the plate) and any wood bucks lining the masonry openings will get nailed to the plate ends, then get Tapconed to the solid end blocks (filled with cement) on each side. Your plates usually need square washers under your 1/2" nuts to satisfy the inspectors.

Your walls will then get built right on top of that plate. Double top plates will overlap at your corners. Typical 8' wall height would be 97 1/8" as measured from the pad surface to the top of your double top plate. Typical rough opening height would be 83" or so assuming 2x12 headers that is 11 1/8" wide. You can build wall sections on the ground and then just set them up there and fasten them, assuming you can do the math. Your stud layout will usually always be pulled from the left side of the building, since most guys like to work left to right. So you hook your tape on the end of the plate and all your wall studs should be centered on 16's or 24's depending on how you want to frame it. And assuming your block walls are level, you use that first sheet of plywood sheathing to plumb your wall up by racking the wall to line up evenly with the edge of the plywood.

Not sure what else you would like to know, I'm starting to ramble.

 

Thank you, that was everything I needed to know and more. I want to make sure its done right so inspectors want be on my back.

 

As stated check with your local building dept. In my Twp anything under 250 sq ft does not require a permit or any inspections. The theory being is that your primarily dealing with small Rubbermaid or aluminum sheds.

Two years ago, built nearly identical 10x15 shed on an old swim spa slab (6") without rat wall!

So the obvious question, why half wall, lot of extra work!

 

Simple answer is cost, I can get a better deal on cinder block than lumber and I think it will look better than a full cinder shed.

I checked with the city about permits and any dimension over 12' will need a permit.

 

A single row of block is all you need to get you above grade enough to prevent the sheathing from rotting and would look far better..
We have to be missing something in your logic using a 4' block wall.
Do you think you need 12' high walls?

 

Possibly, but I think a half cinder block wall with some type of half siding will look odd but it's your shed, do as you please!