Sealing the Building Envelope - page 1 of 4 by Dennis Kulesza
Facility management has become a complicated discipline in today's changing world. Concerns, such as, strategic planning, ergonomics, bench marking, accessibility, post occupancy building evaluations, partnering and down sizing continue to devour a facility manager's time. It is little wonder that building leaks do not rate preferential treatment. Inevitably, though, keeping a building safe from water infiltration becomes an important part of every facility manager's duties.
Water infiltration causes major problems to a structure. Water damages a building first cosmetically then structurally. It is important to realize is that by the time a stain shows up on the interior of your building most likely irreversible damage has been caused to the exterior. Water soaked roof insulation will never dry out. The effective "R" value of the insulation is now destroyed. Trapped moisture in insulation can also decay a roof deck and will cause roofs to fail prematurely. Water entering walls will rust steel relieving angles and carrying beams which support the structure. Moisture penetrating reinforced concrete structures carry chloride ions which will rust reinforcing bars causing them to expand in size resulting in spauling concrete. As one begins to understand the mechanics of water infiltration one begins to understand the importance of keeping a building watertight.
The best way to prevent water from entering a structure is to implement a scheduled maintenance program which incorporates routine visual inspections. Table 1 & 2 are checklists typically used when inspecting roofs and walls respectively.
Roofs should be routinely inspected in the spring and fall. Inspecting a roof in the fall will allow you to ready your roof for the winter. Fall is a good time to check drains and gutters to see that they are free of debris. Clearing debris from drains is a simple task during mild weather but it becomes a difficult if not impossible once temperatures drop below freezing. Inspecting a roof in the spring helps identify damage caused to the roof over the winter. Make repairs before spring rains begin to prevent water from causing permanent damage to your roof. Cursory inspections should also be done after wind storms and after any work is done to your roof or roof top equipment.
Walls are typically more durable than roofs and usually require inspection once a year. A close look at
Tables 1 & 2
reveals that many of the items on the roof check list also appear on the wall check list. An example is coping and counter flashings. This occurs because both the roof system and wall system depend on these building components to keep water out. These components make the transition between systems and are actually shared by the roof and the walls. To help illustrate and explain the relationship between roof, wall, and horizontal waterproofing systems within the same structure the concept of the "Building Envelope" has been developed.
Continue
|