I need help with the foundation.

[Knock Kneed Hen]

I have 16" cinder blocks on a flat pad. I'm building an 8x8 shed row style coop in a high wind area. Other than digging down several inches for leveling the blocks,
how else should I prepare this step?

I was planning on filling the cells and the surrounding hole (which is also just a few inches) with concrete. I'm a housewife, not a contractor. If I were a contractor
I'd lay a green plate on top and shoot it into the blocks. I don't want to have to go back and fix something if I can take care of it during the building process. The building
will end up being inches from the ground so there will be little "lift" from the wind.

I'd love to see pictures of how to lay square off the foundation if you have any.

 

[DangerChickenHouse]

Me too!

I didn't square mine off. It looks good, but it's not level!

 

[MadChickensVT]

If you put bolts with the head down in the concrete when it's wet they should hold pretty well. You can then drill matching holes in a pressure treated 2x and use nuts and washers to bolt the 2x down.

edit: There's actually special bolts with an L shape for this. Thanks to my wife for the reminder

 

[9Catsz]

Quote:
Thanks for that idea. I'm getting ready to start a coop and I'm planning on using concrete blocks just like the OP and I was wondering how to attach the wood to them.

 

[Knock Kneed Hen]

Thanks MadchickensVT! I'll put those on my list

Now anyone out there want to teach us how to square and level the foundation?

 

[Bear Foot Farm]

You can get it pretty level by driving stakes in the ground and pulling a tight string with a "line level" over where you want it, and take measurements from the string to the ground as you dig

Once you get it close, you set the first block using a level, and lower the string so it is within about 1/8th in from the block, and set the rest of the blocks the same distance from the string

To get it square, you need to measure diagonally from corner to corner and make sure it's exactly the same
You can do that with the stakes and string also

The best way is to make "batter boards":

http://www.cedarshed.com/foundations.html

Line levels:

 

[Knock Kneed Hen]

Thanks Bare Foot Farm! My problem was I was trying to use a regular level...

Yeah, I'm blonde.

 

[IRChicken]

Quote:
How strong are the winds, what MPH gusts do you get?
There are different methods for varying MPH, the higher the MPH the more that must be done to secure a structure. In a windy area face the corner of the building into the wind. This will reduce the surface area that the wind can push against.

Quote:
A pressure treated bottom plate is only required if the walls will be resting on concrete that has ground contact. Since you're building a frame that will have joists with plywood on top of that, your walls will sit on this as a base, a PT bottom plate isn't a requirement. Your frame and joists should be built using pressure treated lumber, though not a requirement for a shed.

IBC states that any shed or playhouse 120 square feet or less does not require a permit, some towns or cities may have code with more stringent requirements than the IBC standards.

If anchoring is not needed, then in each location of the concrete blocks, dig out a 24" wide x 24" long x 12" deep hole, fill with gravel. This will provide a stable surface to place those blocks onto and prevent them from shifting or sinking.
If anchoring is needed, dig an 8" round hole to the frost-line, fill with concrete, place anchor bolts into drying concrete. (Make sure concrete is firm before placing the anchor bolts or they will become concrete reinforcing bolts instead.

) This is a lot of work for a shed, but a requirement in some municipalities.
Alternate method: Level your existing blocks, then use Ground Anchor Screws a.k.a. Tent Anchor Screws. Some are rated at 4 tons per Anchor Screw. The advantage of these are they can be added later and attached to the frame with galvanized wire.

To level for an 8'x8' frame, you will need a 10' 2x4 with no crown that is straight and a 4' level. Standing the 2x4 on it's short side with level on top of that, you now have a 10' level. Place one end of your 10' level on any block, the other end on any one of the other three blocks. Check for level and make a note of the height difference, the space between 2x4 and block, with a ruler. Check the other 2 blocks in the same manner. Determine which of the four blocks is the lowest. Dig out the other three, checking often, until each matches the lowest block within 1/4".

To square, measure diagonally from one corner to another, note the length. Do the same for the other corner, forming an X. Each line of the X, / and \\, should be of identical length.

Edit: Line levels are OK on short distances with a very taught line, but on long distances the weight of the line will make the line level useless and inaccurate. Distances over 25' can have a lot of sag, but distances less than 25' should be OK. The greater the distance the more sag is present.

 

[Knock Kneed Hen]

@ IRChicken We get 45-55 mph winds with gusts up to 75. We've had higher! I have dug out under the blocks, but only about 9 1/2 inches down though. Looks like I'll have to go down deeper.

I was planning on doing just 4.8 ft. in the back and 6 ft in the front to reduce surface area. I'm going to attach the run to the coop as well as to the horse run in right next to it. That'll help stabilize it as well. I've learned in the 12 yrs since living here there is no such thing as over building it!!

Gotcha on the green plate. Good to know. Will save me a few bucks.

Great help here!! I'm determined to do a good job.

 

[Bear Foot Farm]

Rather than digging the entire footing deep to anchor it, you can dig "post holes" at several points that will fill in when you pour the concrete. Make them a little wider at the bottom than at the top

Set your block so the post hole is beneath the hole in the block when it's all square and level.

Measure and cut your sill plates and drill holes for the anchor bolts over the post holes, and attach the anchor bolts to the plate.

Then when you fill the holes and blocks with concrete you can set the plate while its still wet and the bolts won't fall in.