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Block-Laying Basics

Building Brick Corner Leads

A

remains consistent from batch to batch.

To make a midsized batch, I fill up two 1-gallon buckets with masonry cement and one 5-gallon bucket plus one 1-gallon bucket with sand. To make a small batch, I fill up one 1-gallon bucket with masonry cement and three 1-gallon buckets with sand. This basic 1-to-3 ratio of sand to cementitious materials (the combination of portland cement, lime, and other addi- tives that are used to make the various mortars) is the same for most mortars.

Because the moisture content of sand varies, so does the amount of water that must be added to the mixture to get it right. Basically, the mortar should be as wet as pos- sible and still be workable. Wet mortar is sucked up into the pores of the units and, in the finished wall, forms a tenacious bond. However, mortar that is too wet is just about impossible to work with and makes a mess of the finished wall. And mortar that is too dry does not bond well with the units.

D

Trowel Techniques

Good, workable mortar is soft and mushy but not soupy. If you’re mixing it with a mechanical mixer, it should flow through and around the paddles in thick globs, leaving noticeable voids in each paddle’s wake; if you’re mixing it with a mortar hoe, it should pass easily through the holes in the blade, forming cylindrical-shaped

B

C

Figure 4. The author uses the edge of his trowel to quickly align the brick that he’s laying with the one below (A), then uses a level to make sure the corner is plumb (B). When the mortar has had time to set up, he uses line blocks to hold strings (C). Because string ten- sion can pop a freshly laid brick right out of the mortar, he some- times runs the strings long and uses line twigs as guides (D).

NOVEMBER 2006 I JLC I 7

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