Key Indicators of Building Envelope Failures in your Building
Over time, all building envelopes will deteriorate, but some will fail prematurely. Protecting the building envelope is of primary importance when it comes to proper building maintenance and uniformity in appearance. Fortunately, there are a several key indicators that will let you know if your building has an issue without an expert review and a walk-through of the facility. This gives you time and opportunity to fix problems before they become expensive emergencies.
The following are the top 8 signs of building envelope failures:
Mold & Mildew
Mold and mildew are a normal part of the world around us. But when they appear inside buildings, it is a sign of problems with your building’s envelope (the exterior walls, roof, windows, and doors). These problems can cause significant health problems for you and your family. Trouble spots include:
- Ceilings – Mold and mildew usually start showing up on ceiling tiles located over bathrooms or kitchens or near leaky air conditioners.
- Walls – If your home has wood-framed drywall, then you may see growth anywhere there’s a water leak or high humidity. Homes built with concrete block walls don’t typically have this problem.
- Carpets and rugs – If you recently had a flood in your home, then you might see mold growing on carpeting and even in the padding underneath. This doesn’t mean the carpet will have to be replaced. It can often be cleaned successfully with specialized products that remove mold and mildew stains without harming the carpet fibers.
If you discover mold, then it’s important to address all the sources of moisture that are causing it to grow as quickly as possible. Otherwise, you’ll just keep seeing more and more of it!
Condensation in building envelope is a very common phenomenon. Trouble with condensation usually starts when air inside a building (in the roof, walls, or floor) becomes warmer than air outside of the building. This difference in temperature causes a pressure difference that results in some of the interior air escaping through cracks and openings in the envelope (roof, walls, windows, doors). As a result, warm indoor air contacts cold surfaces inside conditioned spaces and forms water droplets. These water droplets are typically invisible and form on various building elements like studs, joists, trusses, or cladding.
The most common factors for condensation are:
- Cracks, holes and voids;
- Poor detailing/erosion of insulation due to wind driven rain;
- Condensation from wet pipes, wiring, etc.;
- Ventilation/air circulation problems; and
- Wet external cladding or roofing material.
Cracked or Warped Walls or Ceilings
Cracked and warped walls or ceilings are very common in older buildings. Cracks may occur due to structural movement and can grow over time, especially if the structure is not well-supported. Warping occurs when the building envelope is compromised. The roof covering may be too heavy for the roof structure and/or windows may be leaking.
Deteriorating paint in building envelope is one of the major causes of moisture infiltration and mold growth. The problem is that deteriorated paint can’t be seen from the surface. It needs to be tested. And we are talking about layers of paint here. That’s why it is important to test the wall paints once in a while in order to find out if they need restoration before the damage becomes more extensive.
Here are few reasons why this happens:
- Weathering, which takes place due to physical exposure to natural elements such as wind and precipitation (salt)
- Physical damage, i.e., an impact with a hard object
- Chemical damage, i.e., penetration of harmful chemicals through cracks or holes in the paint film.
Sagging Doors & Windows
Sagging doors and windows are common problems in a building envelope that has been damaged by years of neglect allowing wind, rain and cold air inside your building.
The most common causes of sagging doors and windows are: Moisture (water or humidity), Poor door or window construction, Inadequate support for the frame, Deterioration of materials over time (especially wood and vinyl)
Drafts & Cold Spots
A draft is an air leak through gaps in the building envelope, which causes heat loss. A cold spot is an area in a room that remains noticeably cooler than the rest of the room. Troubleshooting drafts and cold spots in buildings is a two-part process: locating the source of the draft, and then sealing it.
The first step in locating the source of a draft is to determine whether there really is one. To make this determination, perform the following steps:
- Turn off all sources of forced-air heating and cooling (furnace blower, etc.).
- Observe whether condensation forms on cold surfaces (windowpanes or walls). Condensation indicates that outside air is leaking into the house through cracks or openings in the building envelope. If you don’t see condensation, there probably isn’t a draft.
- Observe at what locations condensation forms. Usually, this will indicate where the most significant cracks are located. When condensation forms in several different places around windows, doors or other openings, you may have multiple sources of air leakage. In this case, it’s important to seal each source as completely as possible before proceeding with further sealing efforts. Otherwise, you’ll have to track down each new leak as it develops over time.
- Seal all
Heating & Cooling Issues
Heating and cooling costs are the largest energy consumers in buildings, typically accounting for 50 to 70 percent of total energy use. A building envelope that is not adequately sealed, insulated or air-sealed will have a negative impact on the operating efficiency of a building’s HVAC system. This may lead to excessive energy use, increased operating and maintenance costs, and occupant discomfort.
In most cases, heating and cooling failures can be addressed by improving the building envelope. This includes:
Sealing any gaps or cracks in the building envelope – both inside and outside walls. Adding insulation to any areas of the building envelope that are not well insulated (e.g., crawl spaces). Weather-sealing all doors, windows and other openings in the building envelope. Installing appropriate attic insulation if the attic is not already properly insulated.
Improving a building’s envelope should be a major priority for every facility manager because these simple upgrades can produce significant savings over time and help facilities meet sustainable building goals.
Tearing and Peeling Paint
Paint that’s peeling or crumbling on the walls can potentially be a sign of building envelope problems. If you see this, it could mean that something may be rotting behind the walls or that there are cracks in the outer shell of your building. If moisture gets into your walls, it can cause mold growth, which is dangerous and can make your building uninhabitable. This can also be a problem for the structural integrity of your building and lead to increased risk of flooding and roof leaks.
Paint that’s beginning to peel away from windows or doors could mean any number of things, but it’s definitely a warning sign from your building envelope. Another big reason for peeling paint is poor maintenance — if you’re not caring for your exterior walls, they’ll start to degrade more quickly and lose their effectiveness as insulators against outdoor elements like heat and cold as well as moisture.