Retail Source

Written by Tom Berg, AIA

E-mail: bergtdm@aol.com

A building with masonry gives the sense of permanence and lasting value, but is this fact, or just a notion left over from a time long, long ago? Well, the answer is both. We can find Cinderella castles all over Europe, many dating back hundreds of years. These old stone structures have given masonry its reputation for strength and durability. We can also find relatively new buildings of brick veneer (less than 50 years old) where the masonry has grown old and is being replaced. As a building owner, if you are looking to masonry for lasting durability and value, here are a few useful tips to help you realize your goal. This article is the first in a series that deals with masonry buildings and ways you can tell if you are looking at lasting value or future problems. Specifically, this article is about buying an existing building

Many commercial/retail buildings may look like solid masonry construction from the street, but in fact, the masonry is only skin deep. The real building might be of wood frame construction or steel post-and-beam, with the masonry only a veneer. This type of construction is generally less costly than solid masonry walls, and when constructed properly can give well over 100 years of valued service to the building owner/occupant. Masonry veneer construction, however, is a substitute for solid wall construction, and builders have gone through a learning curve since veneer construction became economically popular in the late 19th century.

Solid masonry walls work very well at stopping water/moisture migration from the exterior to the interior of the wall. One of the early misconceptions about veneer masonry constriction is that it would perform as well as solid masonry, but time has proven us wrong in this assumption. Masonry veneer does leak, and we may not know there is a problem until there is major failure of the building wall. As a potential building owner, how do you tell if a building is going to perform well? Is it really a bad investment plagued with maintenance problems or will it give lasting service with minimal care? Here are some things to look for when buying an existing masonry building.

Some signs of failure in masonry veneer can be observed on the exterior of the wall. The more dramatic of these is cracks caused by building movement or settlement of the foundation. Other signs of failure are more subtle, like moss growing on mortar joints, and rust stains on the face of the wall coming from no apparent cause. Start your inspection at the top of the wall from the roof (not from the street) to see if the copings are tight. Copings in older buildings and on many newer ones as well are constructed of individual masonry units set in place with mortar. These mortar joints are a prime point of entry for water. Joints between coping units must be in good condition. That is, they must be full of mortar, tightly bonded to each masonry unit, and solid when scraped with a pocketknife. Copings should not move. Any loose coping unit is not only a hazard to people below, but can allow gallons of water to enter the building.

Some buildings may have a metal flashing under the coping. The intention of this flashing is to prevent water from entering the wall through the coping, but this doesn't always work. Metal flashing is very dependent on the skill of the installer, and improperly installed flashing may be worse than no flashing at all. So, while you are on the roof, look for flashing under the coping. If it is there, it must extend beyond the front and back face of the wall, and the front edged should be turned down so water can drip off. Flashing installed in any other manner will allow water to enter the wall, and may even trap it there.

Walk around the building. Look at all corners for vertical cracks. These cracks are an indication of brick movement due to expansion over time. A building 100 feet long can grow ½ inch and more. If the designers did not provide for this expansion with vertical control joints, there will be cracks at the building corners. These vertical cracks are especially harmful to a building because it is at the corners where the building's structural system often works the hardest. Leaks at this location can cause rot in wood framing and rust at steel column and beam connections. Look for moss growing on the mortar joints. This problem can indicate a number of conditions, such as, soft mortar, cracked mortar, or just a lack of a good sealer to keep the mortar from becoming saturated. Older buildings might have a soft, lime-based mortar that acts like a sponge in wet weather. In addition, as buildings age, cracks can develop in the mortar creating a place for water entry. If this wet mortar doesn't dry out, moss or other vegetation can begin to grow on the face of the mortar. If there is a crack, moss will often grow in a very straight, thin line directly over the crack. Mortar that stays wet and mortar with biological growth is losing strength and will need to be cut out and replaced. Look at the shape of the mortar joint. Mortar that is "raked" back from the face of the masonry may look nice, but it provides a small ledge for water to collect. If a crack should develop in the mortar, this ledge acts as a collector for water, feeding it back into the crack. The best joint is flush with the face of the veneer and tooled to a slight concave shape.

While you're looking at the mortar, get out your pocketknife and check for cracks between mortar and adjacent masonry units. Cracks develop in older buildings, but should not be present in new construction. If you find cracks, this is again a place for water to enter the wall. In new construction, this may also be an indication of poor construction such as using mortar that is too hard for the adjacent masonry, or allowing the mortar to dry out before it was used in the wall. In any case, the life of the wall is in jeopardy, and maintenance will be needed far sooner than should be expected.

Look for rust stains that appear to be coming from nowhere. Masonry veneer is anchored to the wall with metal "ties." During the early years of masonry veneer construction these ties were often made of 9-gauge wire or corrugated sheet metal, and might have little or no rust inhibitor on them. When water enters the veneer cavity, these ties are most vulnerable to corrosion. In many cases, they are completely rusted away before a building owner knows there is a problem. By this time there, is nothing holding the veneer in place other than its own weight. As you look at the wall, look for rust as a sign of interior damage that may need very expensive repair. Masonry veneer is known to leak, so there should be a system of weeps at the bottom of the wall to allow this water to get out of the cavity. If water is trapped in the wall, there is a great chance that rot and/or rust is occurring in the wall, and may be occurring in the main structure of the building. As you walk around the building look for small holes in the wall just above the foundation. If it has been raining, see if these holes are weeping water. Look for stains below these weeps. If there is enough water in the cavity for these weeps to be active, there is too much water getting into the wall, an indication of other failures above. In no case should the veneer extend into the ground. This condition will block any chance for weeps to expel water from the cavity, and brings additional water into the cavity wicked upwards from the ground.

After looking at mortar cracks and moss and weeps, step back and get another overall view of the building. The veneer should be flat, dead flat. If there are any bulges in the veneer, this is an indication of structural failure of the veneer, and very expensive repairs may be needed. When purchasing an existing masonry veneer building, ask for a history of repairs. Find out when the building was last cleaned by a professional masonry restoration and repair contractor. When was the masonry last sealed (if ever)? If work has been done recently, talk to the restoration company to learn more about the building. If you find lots of cracks and moss on a building, hire a reputable masonry contractor to look at the building and to give you an estimate of cost to clean and repair the building. Remember, masonry veneer buildings may look solid, but they can take a lot of tender loving care to keep them working like their solid-wall cousins of many years ago.