Building Envelope Maintenance, An Organized Approach

What is there to do during a winter in New England? Certainly snow sports, a good book, or dreams of spring golf are all excellent pursuits. However, for the chairperson of a condominium maintenance committee, winter is a good time to be planning building envelope repairs. The building envelope comprises the roof, siding, and foundation, along with all of the windows, doors, and other penetrations that go with the envelope.

As the building envelope is probably one of the most important, if not the most costly common condominium asset, it bears careful monitoring. This article serves as a brief guide for the typical problems and issues encountered in most condominium buildings, the bulk of which are associated with water infiltration.

Starting from the top, most condos use asphalt shingles for sloped roofs and EPDM membranes for flat roofs. Both last a long time. Asphalt shingles have an expected useful life of approximately 25 to 30 years, while EPDM membranes start to fail after about 20 years. Most roofs start to show their age by leaking, with the great majority concentrated in areas where dissimilar materials or horizontal and vertical surfaces meet. Defective or poorly installed flashing is usually the culprit.

Caulking or roof tar is often used for repairs, however these tend to be only temporary fixes. Watch for curling or lifting shingles as these are good signs of an aging roof. Roofs can also fail prematurely from overheated and poorly vented attics. And speaking of attics, the irony is that ice dam leaks are caused by heat rather than ice. Ice dams are formed at the edges of roofs due to heat escaping into the attic. This heat, escaping from poorly sealed exterior walls or inadequate insulation, melts accumulating snow on the roof which creates a freeze/thaw cycle that eventually works under the shingles. These issues should be addressed prior to installing external electrical heat tape or similar measures.

Many of New England’s condominiums are sided with wood, vinyl, or cement composite clapboard siding. For the most part, these materials do their job to keep most of the moisture out of the building but they are not the only barrier. In fact, one of the most important components of exterior walls is the building wrap beneath the siding. This material’s purpose, going by such names a Tyvek or Typar, is often misunderstood, even by contractors.

Know by many as a “vapor barrier”, building wrap should really be called “building flashing” as that is its true purpose. Water gets behind all siding whether it is clapboards, brick, or stucco. The trick in good building envelope design is to ensure this water infiltration is stopped by a drainage plain which, for most residential structures, is building wrap. This is why most exterior wall leaks can be traced back to missing or poorly installed building wrap.

It is critical that seams in the building wrap (particularly vertical ones) are taped, holes are patched, and the wrap is properly integrated with the flashings around doors and windows. When a unit owner reports a water infiltration problem through the walls, it is a good idea to focus on problems with the wrap rather than the siding. To make matters worse, if the wrap is failing it is very possible water damage may also be occurring to the sheathing and insulation behind the wrap.

This brings us to windows. The problem with windows is they typically belong to the unit owner and are not a common element under most condominium rules. However, the building committee is not off the hook with window leaks as these same condo rules that assign the windows to the unit owners also assign the window frames to the association’s responsibility. In most cases it is not the window that is leaking but the frame’s flashing (or lack of flashing) causing the problem.

Poorly installed windows that do not follow the manufacturer’s instructions are one of the biggest sources of homeowner complaints. Often the only solution is to remove the siding around the window, inspect the flashing, and re-flash. Many problems can be minimized by preventive inspections using either visual methods or instruments such as moisture meters to focus on the specific moisture path to diagnose the issue.

Water infiltration problems are like odd noises in your car. They do not go away, they only get worse. By addressing these problems now your dreams of early spring golf may yet be realized.