How to Anchor a Metal Storage Building with Cinder Blocks

Preparing the Site

• 1

  Mark the perimeter of the shed location on the ground by driving wooden stakes at each corner and drawing a cord tautly around them.

• 2

  Measure 1 foot on each side of the string – around the perimeter of the shed site – and mark the ground with powdered chalk.

• 3

  Remove the stakes and the string. Use a shovel to dig out the space between the chalk lines to a depth of 28 inches while keeping the bottom surface of the trench level.

Laying Blocks

• 4

  Place a line of preblended masonry mortar – mixed with water according to package directions – that is 4 inches wide and 1 inch deep, along the middle of the trench on one side of the shed perimeter.

• 5

  Lay a cinder block in the mortar and butt the block snugly against the corner wall. Tap the top of the cinder block with the trowel to level and seat it firmly into the mortar. Lay a carpenter’s level on top of the block and continue to tap it until it is level.

• 6

  Set a cinder block on one end and place a 1-inch-thick layer of mortar on the other end. Place the end of the block against the end of the first block, tamp it in place and use the carpenter’s level to level it.

• 7

  Continue using the same process to set cinder blocks along the trench. Lay a line of masonry mortar that is 4 inches wide and 1 inch deep along the bottom of the trench on the next side of the perimeter.

• 8

  Stand a cinder block on its end, apply a 1-inch layer of mortar and seat it firmly against the side of the last block laid. Continue laying blocks along this side of the perimeter just as you did the first side.

• 9

  Lay cinder blocks around the two remaining sides of the perimeter using the same process as you used for the first two sections.

• 10

  Spread a 1/8-inch layer of surface bonding cement with a trowel on the top of the first block at the corner of one side of the trench. Position one-half of a cinderblock on top of it and use the carpenter’s level to adjust the block to level. Continue this process with whole blocks – making certain the seams where the blocks join overlap – around the entire trench. Lay a third course of blocks on the first two layers using the same process.

Anchoring the Shed Frame

• 11

  Fill one side of the hollow portion of the block on each end – and the block in the middle of the wall – with masonry mortar. Place a 5-inch-by-1/4-inch heavy-duty bolt upside down in the cement in each cinder block. Push the bolt down into the cement for a distance of 2 inches. Use a small spirit level to ensure the bolt is in plumb. Allow the cement to dry overnight.

• 12

  Position a 2-by-8-inch board on top of the cinder blocks along the length of each side of the shed perimeter. Mark the spot on the underside of the 2-by-8-inch board where the bolts touch it.

• 13

  Drill vertical holes through the 2-by-8-inch boards at each spot where they were touched by the bolts.

• 14

  Drop the 2-by-8-inch boards over the bolts so that they protrude through the holes you drilled in the boards. Place a heavy-duty washer and nut over the bolts and tighten them securely with a crescent wrench.

• 15

  Place the frame of the shed over the 2-by-8-inch boards. Space blocks of 2-by-8-by-12-inch board evenly along the frame-board of the shed. Anchor the shed with heavy-duty lag bolts through the board, the frame-board and into the board on top of the cinder blocks.

• 16

  Fill in the trench with the excavated dirt and use a hand-tamper to tamp the dirt solidly around the foundation wall.