Block Choices

• While cinder blocks have a traditional shape, they also come in many varieties, each with a slight variation. The standard block will always be 7 and 5/8 of an inch wide, but can come with two or three hollow cores, and a number of different edge configurations, including steel sash, wood sash, bullnose, capping, header and more. Different designs help builders construct more complicated patterns with cinder blocks, giving options to build at angles, create corners, and cover pipes or beams without any space showing. You will probably only need the average two-core size, which is available in slight variations. If working on a more complicated project, be sure to have the design set out and choose your building blocks carefully.
  
  

Preparation

• For cinder block walls, a cement base is always suggested. As a rule of thumb, the base should be dug at least twice as deep as the thickness of the wall and twice as wide. If this does not go beneath the frost line where you live, you should probably make it even deeper. The cement pattern is held by using rough 2-by-4s to frame it--and the 2-by-4s in turn are held in place with stakes driven into the ground at the edges of the trench. Quick 2-by-8 fortifications can be built to make space in the concrete for any supply lines that need to passed through the wall.
  
  The best way to judge how many blocks exactly will be needed is to construct a wooden form at each corner of the wall, built out of simply wooden stakes made in the shape of the corner. String can then be tied from one stake form to the other, creating the precise angles and corners based on where they meet. Plumb bobs can be dropped where the corners meet for more exact measurements on the stone. You should always place your bottom layer of blocks down along the lines to see how many you need and how they will fit, prior to laying them.
  
  

Laying

• Once you have the correct corner and line markings in the cement, lay the mortar, spread one inch deep and about 8 inches wide. Place the corner brick first, and measure it to be sure it is even and level. Base the other bricks on the first level by this corner brick, laying mortar as you go. Every few bricks use a level to ensure the row is perfectly even and straight on all sides, making small adjustments as you go.