Building Brick Stairs - Continued
The kind of precision required for trim carpentry was not
necessary here; the wonderful thing about masonry is that small
imperfections can simply be filled with mortar. Still, clean
cuts that are close — within 1/8 inch or so —
really make the job look good.
Building Steps That Drain
To accommodate an external drainage system designed to minimize
hydrostatic pressure on the steps, I had made the excavation 6
inches wider than the structure. I lined that 6-inch space with
filter fabric, placed a piece of standard plastic drain tile at
the bottom, and filled the space up to within a few inches of
the top with pea gravel (Figure 5). Then, after folding the
filter fabric over the gravel, I back-filled the last few
inches with dirt. Left over from prior jobs, the filter fabric,
drain scraps, and pea gravel cost about $15 (the total expense
of the external drain system, not including my labor).
Figure 5.A perimeter drain system around the base
of the wing walls helps guide groundwater away from the steps,
keeping hydrostatic pressure to a minimum.
I also wanted to provide an outlet for any water that managed
to penetrate the steps. To do this, I used CMUs for fill as I
built the steps; clean channels between the CMUs lead to weep
holes at the bottom of the first two steps. As I laid the 2
1/4-inch blocks that backed the stretcher courses and the 3
5/8-inch blocks that backed the rowlock courses, I used a
tuck-pointer to keep the channels between the blocks free of
mortar, leaving an unobstructed path for water to run to the
weeps. I swept fine gravel into the joints to prevent mortar
from succeeding courses from blocking the channels (Figure
6).
Figure 6.To ensure drainage, the author used a
tuck-pointer to remove excess mortar from between the blocks
(top left), then swept crushed stone into the joints (top
right). Water runs out through weep holes left at the bottom of
the first two steps (bottom).
Although there were slight differences between the wing walls,
I used a straightedge to get each step straight and neat. To
minimize water intrusion, I laid the bricks with full,
compressed joints, using a tuck-pointer to fill the joints and
a sled jointer to pack them tight (Figure 7).
Figure 7.With a sled jointer, the author packed
the mortar tight and made clean, concave, water-resistant
joints.
While building the wing walls, I'd intentionally left openings
in the rowlock course to accept the original stair's
wrought-iron railing (though I could have made these openings
with a hammer drill). By the time I completed laying all the
steps, the brickwork in the wing walls was completely cured, so
I was able to install the railing using Quikrete's Anchoring
Cement (800/282-5828, www.quikrete.com), a portland cement
product that expands slightly as it cures. I inserted the
railing into the holes, braced it plumb, and then poured the
anchoring cement into the space around its legs. A day later,
the railing-to-wing wall joint had a pull-out strength of more
than 12,500 psi.
Even though none of the steps are the same width at both ends
and none are precisely level, the overall staircase is strong,
comfortable to use, and pleasing to the eye. It should last for
generations.
John Carrollis a mason and builder in Durham, N.C.,
and the author of Measuring, Marking, and
Layout.