Masonry Block Building Tips.  Every block wall-regardless of height or length-should be placed on a secure footing of poured concrete. A block barbecue grill or outdoor fireplace requires a large concrete pad as a footing. The footing must extend down beyond the frost line to prevent heaving in the winter.

For a footing poured in an area where drainage is a problem, lay a drain line along the outer edge of the form. Allow for a drop of about 1″ for each 20′ of drain line. Backfill over the drain line with about 12″ of crushed stone or gravel. In Ontario this is mandatory and must be installed for any building of 100 square feet in size.

Building exact corners is the most important construction of a masonry wall as corners will guide the building of the rest of the wall. A corner pole will make the job easier. A corner pole is any type of post which can be braced into a true vertical position and which will hold a taut mason’s line without bending. Two such poles are set up, one on each corner, with the mason’s line stretched between them. Corner poles for block walls should be marked every 4 to 8 inches, depending on how high the material is with which you are building the wall. Such marks must be absolutely level when the mason’s line is stretched between them.

Set the corner block first. Be sure you are using the correct block. Check the starting corner block, both horizontally and vertically, and take time to get it positioned correctly. All other blocks will align with this starter block, so it’s very important to set it exactly. Follow this same procedure as you reach the other corners, laying the first course out about two or three blocks in each direction. Tie a line between two bricks and stretch it between the two corner blocks on the first course.

Corners and lead blocks are generally built 4-6 rows high, with each course being stepped back one block from the course below, creating a pyramid effect. The wall alignment, plumb and level should be checked on these corners before completing the wall. If everything checks out fine, it is now time to fill in each course between the corners.

Because they can be adjusted in size slightly, mortar joints provide some layout flexibility. While the ideal mortar joint is 3⁄8 inch wide, masons routinely shrink joints to as small as 1⁄4 inch or stretch them to as large as1⁄2 inch. Joints that fall out- side this range are unsightly and, with a few small exceptions, prohibited by most building codes.

The Barrie Home Inspector uses his training to ensure every building inspected meets or exceeds the required building code practices. As a Certified Building Code Official he is one of the few Barrie Home Inspector’s with Ontario Building Code training in both Part 9 and Part 3 of the Building Code.