How to Build a Brick Wall Over Wood

Prepare a base, preferably concrete, at least 6 inches wide from the face of the wall. Dig a trench with a shovel and pour a concrete base if one was not installed as part of the house foundation. Bolt steel angle iron to the base plate of the wall as an alternative. Use a level to get the base level and ensure it extends right to the bottom of the wood sheathing.

Install metal flashing over the base; extend it up the side of the wall and over the base. Attach it to the base with a 1/2-inch layer of mortar. Put flashing around any windows, doors or other openings; nail this to the wood sheathing with galvanized nails and a hammer. Staple a waterproof membrane over the sheathing with a construction stapler. Fasten it tightly to the sheathing with no gaps or sags.

Use a chalk line with a line level to snap a level line the length of the wall about two bricks high above the base as a guide for the base course or layer of brick. Assemble the facing bricks alongside the wall where they can be easily reached. Decide on a pattern; a "running bond" in which one brick overlaps two other bricks by half a brick is the easiest.

Mix mortar according to directions on the package; it should be firm enough to stand on its own, but fluid enough to spread easily. Spread 1 inch of mortar on the base with a pointed mason's trowel and smooth it approximately level. Lay the first brick in place at one corner of the wall. Press it firmly into the mortar and use a level to ensure the top is level.

Lay other bricks along the first course, putting mortar on the ends to connect the bricks. Use a level to keep the course level. Leave a gap between the brick and the wall membrane so any water that gets in will drain down. Put small pieces of rubber tubing between vertical joints every other brick as "weep holes" to allow any water to drain out from behind the wall; remove the tubing once mortar has set.

Start the second course with a half-brick cut in two with a masonry saw. Put the cut end to the inside of the wall. Spread mortar on the bottoms and ends of bricks as they are added the length of the wall for the second course. Begin the third course with a full brick and alternate in this pattern up the wall.

Install brick ties starting with the third course. Nail one end of each thin metal strips to the sheathing with galvanized nails and a hammer and place the other end between horizontal mortar joints. Put ties on every stud and every 16 inches vertically. Check building codes for specifics; some high-wind regions may require closer spacing of ties.

Put steel lintels over the tops of windows and doors to support the bricks above; extend these at least half a brick on each side of the opening. Set the lintel on top of the opening framing. Lay a "rowlock" of vertical bricks at the bottom of a window. Cut bricks as needed to fit edges or door or window openings. Measure to door and window openings, or to the top of the wall a few courses ahead of time; adjust mortar joints as needed so full bricks will fit exactly.