Is Your Building Living Its Best Life?
The Importance of a Well-Maintained Building Enclosure
Many people view buildings as static rather than the dynamic, constantly moving objects they are. The building enclosure generally has six surfaces, including the ground the building rests on. And all of these individual surfaces must be considered when maintaining the structure’s integrity with regard to unintended intrusion of air, water, and vapor.
In short, maintaining a building’s enclosure is crucial to its longevity and wellbeing.
The Biology of a Building
A building is like any ecosystem made up of many intricately connected parts. If one part of a building system is affected, it can cause ripple effects with other seemingly unrelated parts. When mitigating a particular issue, you may fix one condition but additional problems may manifest themselves elsewhere.
That’s why understanding issues like unconditioned air infiltration, water intrusion, building pressure, and temperature transference are critical to understanding the dynamics of buildings and their enclosures.
All building enclosures are comprised of materials that contain some level of capillary voids, small spaces such as those created in concrete formed by air bubbles. Capillaries can vary in size:
Some of these spaces are small and closed off to one another, such as within glass or metal.
Some are much larger and interconnected within the material, as is the case with masonry or cement.
Moisture and air transfer can occur within these capillary spaces, sometimes in an adverse way. So, you could repair all visible penetrations in an exterior building enclosure without truly solving the issue of inappropriate air and moisture transfer. But proactive design and/or repair of these enclosure systems can minimize uncontrolled air and moisture transfer.
Impacts of Water Intrusion in Building Materials
In order to understand water intrusion, think of a household sponge. It contains large voids or capillaries that are all interconnected. If the sponge is sprayed with a spritz of water, it retains some of that moisture, and over a relatively short period of time, it naturally dries back to its normal state.
Now submerge that sponge underwater. It becomes fully saturated and will not void this water until force is added (by squeezing the sponge). Once squeezed, the water is voided and the sponge dries relatively quickly.
From a building perspective, our concern is that period of time when the building materials are fully saturated. How will this level of moisture impact those respective building materials?
Gypsum board has many smaller capillary spaces that absorb water. But compared to a quick-drying sponge, these capillaries dry more slowly and moisture reduction takes longer. Plus, gypsum board is an organic material that can become a food source for AMG. That means if it takes longer than 72 hours to dry, AMG is almost inevitable.
There are steps to take if a building’s gypsum board becomes wet:
Apply drying methods (or some force) that can reduce the drying time of the material.
If AMG becomes an issue, it is either recommended to clean and sanitize or replace the impacted materials.
On the other hand, a material like brick is more resistant to mold. It is very porous like a sponge but contains minimal amounts of organic material, so it dries without impacting the internal structure of the brick. This makes brick a great external building material. But the moisture still needs somewhere to go once it drains from the brick, which is why locating a drain plane behind the brick veneer is crucial.
When choosing exterior building enclosure finish materials, consider materials that will not deteriorate with moisture impacts. Always determine where the drain plane is in relationship to the overall building enclosure system. It’s important to maintain that drain plane throughout the system with proper drainage to daylight, usually at the lowest point in the system.
The Importance of a Well-Maintained Building Enclosure
One major threat to a building’s long-term integrity is moisture intrusion, when unintended water or humid air penetrates one of its exterior planes.
Natural forces of equilibrium try to balance the humidity levels and temperature between the inside and outside of a building. So, a building enclosure must:
Manage the transfer of temperature. This is controlled by continuous insulation systems within the enclosure.
Control the transfer of moisture-laden air by the use of air barrier systems.
If an enclosure isn’t properly sealed, moisture can permeate a building in the form of humid air or vapor. These conditions get worse when moisture moves through the capillary spaces within the building materials. All of this can cause moisture to collect, which could lead to degradation within the building materials and mold growth.
Systemic Maintenance Issues
Buildings are not constructed to last forever independently. They require constant attention and maintenance.
Unfortunately, building systems are not always maintained as well and often as they need. As a result, systemic issues arise in building systems including the enclosure. Sometimes, building owners do short-term repairs instead of a longer-term fix due to cost, time, or simply a lack of effort.
This leads to problems down the road. For example, a building developer may ask for a five-year warranty on the construction of an enclosure system. But if no maintenance is performed on that system during those five years, it could lead to a major failure. The repair costs can easily exceed the cost and time of maintenance that should have been done earlier.
Dangers of Water Intrusion
Uncontrolled water intrusion is bad enough on its own, but it may also create other issues.
Look at amplified mold growth (AMG) and subsequent poor indoor air quality. Like other living things, mold needs water, air, and food to survive. AMG can occur when moisture intrudes and saturates building materials such as drywall.
It can happen quickly. AMG may occur within 72 hours after initial moisture contact.
AMG can cause mold spores to be disseminated locally or throughout the building via HVAC distribution systems. Breathing in airborne mold spores can have an adverse effect on the health of the building occupants, exasperating any existing respiratory conditions that a person has along with aggravating other health issues.
AMG isn’t good for building materials either. It can weaken the physical and structural integrity of materials such as wood or drywall. Even more seemingly durable materials such as concrete are not immune to these effects. Concrete-based building materials and more specifically reinforcing steel in concrete structural systems can corrode and dissolve from moisture impacts, potentially affecting the structural integrity of these systems.
How to Measure the Impacts of Moisture on Certain Materials?
If interior building materials are impacted by moisture intrusion, a tool to determine the extent of those impacts is a moisture meter.
A moisture meter measures the locations where there is a high percentage of moisture content in building materials. The process of documenting these locations on a floor plan, called moisture mapping, confirms areas where water intrusion and/or moisture condensation has occurred. It also identifies materials that require drying, cleaning, and/or replacement as part of the remediation process to return the space to an occupiable condition.
While moisture mapping is important, determining the cause for the intrusion in the first place is crucial. A forensic architect can assess the conditions and present recommendations for fixing the issue so that it doesn’t reoccur.
Building Enclosures Work in Concert with HVAC Systems
One of the best ways to keep a building healthy and prevent potential damage is by controlling humidity levels within the building.
It is possible to design HVAC systems to control humidity in the interior, but without a correctly designed enclosure to limit unintended moisture intrusion, the results can be detrimental. Moisture collection reservoirs could gather moisture within the enclosure system and cause deterioration. That’s why the building enclosure and mechanical systems should work in tandem to control moisture intrusion.
Top Takeaways
Having these conversations is necessary whether it’s new construction, building maintenance, or renovations of existing buildings. It’s better to be proactive than reactive when it comes to preventing moisture problems in the enclosure system.
Talk to a qualified building professional to see how you can optimize your building’s function. Depending on your issue and your building’s life stage, you can discuss:
Designing and verifying the correct building enclosure
Specifying appropriate mechanical systems to control humidity and pressure
Limiting moisture intrusion by fixing existing conditions
Renovating your building entirely
By talking to the right professional and taking steps now, you will save yourself money and headaches in the long run.
