December, 2003
Feature
Inspection News and Views from the American Society of Home Inspectors



Drunken Sailors & Weeping Soldiers: Masonry Inspections

MARK OLDROYD

Attennnhut! Actually, this article has nothing to do with the military. These are construction terms used by brick masons. Soldiers and sailors are bricks that are placed vertically (lengthwise up and down). The soldiers have the narrow side (depth) to the front, and the sailors have the wide side (width) to the front. They are called drunken if they are offset or tilted when installed as part of an arch or other architectural detail. Weeping is a condition caused by moisture release.

St. Louis history

The widespread use of clay brick as a building material in the St. Louis area stems back to the early 1800s, when the first brick factory opened on 7th Street in 1816. Others followed and eventually there were 53 brick manufacturers. Only one local brick plant survives today. The Hill area in St. Louis was a major source of clay used in the bricks. In the 1820s the building material of choice was brick due to the higher price of lumber. The brick yards and kilns in the downtown area created such nauseating smoke pollution that an ordinance against making bricks in the city was DSC00113.gifpassed in 1824. It could not withstand the political and economic power of the
industry, and it was rescinded the next year. As in many other areas of the country, the last years of the 19th century and the first decade of the 20th saw construction of countless local brick structures and stately homes in St. Louis. Photo: Missing mortar shows the lack of proper mortar maintenance.

Old brick construction

Clay brick is durable and able to withstand weathering action, chemical attack, abrasion and high winds. The historic brick buildings in the city of St. Louis are constructed with multi-wythe walls. A wythe is a single row (wall) of bricks. Headers laid perpendicular across the two wythes tied them together, usually every six courses (levels or horizontal rows). This masonry technique is called a barrier DSC00111.gifwall. The mass or thickness of the wall protects the interior dwelling space wall from moisture penetration. No weep holes, as seen in modern brick construction, were necessary. Individual brick units were bonded with mortar. The recipe for the old mortar used in historic buildings before the 1920s was mostly hydrated lime, aggregate (sand) and the exact amount of water. After the 1920s, as cement (bonding powder) was added to the mortar mix, the mortar became harder after setting. Photo: A defective and clogged rain gutter system caused serious exterior surface mortar deterioration, thus allowing moisture absorption through the barrier wall and resultant severe damage to the interior walls of both stories.

Identifying problems with old brick construction

From an inspector’s point of view, moisture penetration is Public Enemy Number One, with any residential dwelling and especially masonry. Brick will expand due to the absorption and equalization of moisture. As units rest in the wall and absorb DSC00036.gifmoisture, they can expand a brick wall as much as one inch per 100 feet. Clay bricks wick and absorb moisture, creating capillary action and staining or efflorescence. The white powdery substance (efflorescence) is actually dried minerals left when the moisture evaporates. Bricks cracked through the middle are usually caused by expansion and contraction. Flaking or spalling on exterior brick, as often found on masonry chimneys, is caused by wicked moisture and the freeze/thaw cycle. Photo: Settlement of a shallow arch (as shown here) or rusting steel lintels can create a triangle of damage above doors and windows. This example of re-pointing work is less than should be expected of a craftsman.

Mortar in unlined and/or uncovered chimneys and flues is often deteriorated by acids created  by a combination of rising combustion fumes and condensing moisture. The broken tile cap and mortar seal over the parapet walls (raised short walls) on the roof and the broken or cracked concrete chimney caps are also possible sources of moisture intrusion. Although very charming, ivy and other climbing vegetation on brick walls is deleterious to the mortar and to the brick surface.

DSC00120.gifVulnerable areas include the following: deteriorated sealants/caulking around windows and doors; poorly maintained, blocked and debris-cluttered rain gutter systems and downspout leaders; lack of proper roof seal or flashing above or behind rain gutters to prevent ice damming or overflow; rusting lintels (the load bearing steel shelf above openings, such as windows or doors); and differential settlement of the building as indicated by a pattern of cracks, separations, openings, and missing or loose units. These are deficiencies that should be noted and addressed. Photo: North facing offending wall – opposite of interior damage – with moss growth and missing mortar.

In addition, foundations were constructed with rough irregular stones (rubble stone), which makes the foundation and basement area subject to moisture intrusion from deteriorating mortar and natural expansion and contraction by geologic forces.

Available remedies


As natural forces wear away at exterior masonry surfaces, the bonding mortar is particularly vulnerable. As with any problem, the source and extent of the condition must be evaluated. This may require destructive testing and removal of some building components. The next step is a prioritized plan to correct such deficiencies using well-qualified and experienced craftsmen. Re-pointing (replacing the mortar between the bricks) is not a do-it-yourself project. It requires skill as well as special tools.

When re-pointing, it is critical that an expert craftsman be retained to carefully match the type of brick with the type of replacement mortar.

When lintels rust or settlement occurs above windows, there is a triangle of supporting bricks that can be removed safely and replaced without collapsing the entire wall. Damaged individual bricks can be chiseled out and replaced.

It is virtually impossible to prevent the rubble stone foundations from allowing moisture penetration into sub-grade basements. Interior parging (smearing the interior basement walls with a damp-proofing mortar material) is often attempted, but  rarely proves satisfactory.

Ventilation provided by fans, open windows and dehumidifiers helps manage basement moisture. Good exterior drainage is of utmost importance in helping to prevent moisture intrusion and related problems such as mold. The key is to route all exterior drainage way from the foundation. Do not allow water ponding or moisture accumulation at the exterior foundation perimeter. With regular maintenance and a lot of TLC, these old warriors can still be “standin’ tall and lookin’ good” for another couple of hundred years. …..at ease!

Special thanks to Edgar F. Glock AIA/CSI, Executive Director, and Darrell McMillian of the Masonry Institute of St. Louis, and the book  St. Louis-A Concise History by William Barnaby Faherty, S.J.