16 minutes read
Whether it’s the sweltering heat of summer or the chilling cold of winter, protecting your structure from the outside is a necessity.
For some reason, too many project stakeholders take the building envelope for granted, when prioritizing it can make a world of difference. It's more than just a pretty face. In addition to user comfort, the building envelope can affect energy efficiency, the presence of fungus, and long-term structural integrity.
It all starts at the material level, so that's where the project manager should start too!
Building Envelope Material Staples in Commercial Work
Building envelope systems and materials you should treat as must-have tools for your kit include:
- Air & vapor barriers and flashings
- Waterproofing products
- Curtain walls
- Structural glazing — weather sealing & insulation
- Joint sealants
1. Air & Vapor Barriers and Flashings
Through a variety of building envelope products, you can handle air and moisture from the roof on down.
Barriers offer broad coverage of a section of a building. It's common to lump together certain types inaccurately, so make sure you know what you're buying:
- Air barrier — controls flow of air in & out
- Vapor barrier — stops diffusion of droplets through walls, ceilings, & floors
- Weather-resistant barrier — blocks rain & wind; allows moisture inside to escape
Flashings weatherproof a specific area of the structure. The direct water away from areas that are prone to infiltration.
Consider placing them at any joint or transition a regular barrier might not cover appropriately. Examples include window, door, and roof edges.
The right barriers and flashings can turn a building enclosure into a warm safety blanket of sorts — for people and the structure itself.
2. Waterproofing Products
Meanwhile, a wet blanket isn't very useful.
To the building owner, the basics of below-grade waterproofing are maybe the most important skills in a subcontractor's arsenal. Getting waterproofing right the first time — below and above ground — will mitigate future repair costs, and an effective restoration job can extend a building's life by decades.
Just as contractors use waterproofing membranes on a roof, they can exist on walls, windows, and more. The thin layer of sheet or liquid forms a moisture-tight, vapor-controlling shield. Concrete is porous, so it's a particularly important material to protect from cracking and mold/mildew growth.
Drainage composites are also viable waterproofing solutions in several places in and around buildings, preventing buildup and damage. For heavy-duty areas, hot rubberized asphalt can eliminate seams on systems such as roofs, thus reducing leaks and maintaining a pleasing look.
3. Curtain Walls
Just because a building component is nonstructural doesn't mean its value is merely skin-deep.
There's a mile-long list of solutions for improving a building envelope design for both form and function, and curtain walls belong on that list. Two a curtain wall consists of two external cladding components: frames and infills.
A curtain wall frame doesn't carry any structural load, but it can contribute to the fight against water, temperature, and UV threats. Framing material is most commonly either:
- Aluminum -- high strength-weight ratio; naturally corrosion-resistant
- Steel — can support larger wind and glass loads
- Wood — a unique aesthetic
- Glass — customizable color and visibility
- Metal — can withstand harsh conditions with little maintenance
- Stone — a timeless look
- Windows & vents — use depends on building requirements & aesthetic tastes
- Louvers -- Manages airflow & light for energy efficiency
4. Structural Glazing — Weather Seal and Insulation
The curtain wall is only one of several popular glazing systems. Structural glazing is imperative in controlling the elements and conserving energy.
All these glass walls and large windows and metal panels don't stay up by themselves. A wealth of components and assembly products exist to secure the building envelope against gradual wear and sudden water intake:
- Glazing tape -- adhesive coated on one or both sides, bonding the glass to the frame
- Structural silicone adhesives -- high-strength sealants specialized for insulating load-bearing glass
- Weather seals -- keep out water, air, & other elements
- Gaskets -- stop ingress during downpours and heavy winds
- Spray foam -- plastic used to insulate gaps and cracks from air, heat, & cold
5. Joint Sealants
Air and water leaks invite moisture damage, create a breathing hazard, and suck the energy efficiency out of a building. Joint sealing is a crucial step in weatherproofing a building from these threats, as it fills the dangerous gaps between two substrates.
You can and should find joint sealants nearly everywhere on a construction site:
- Between panels
- Around windows & doors
- Termination points
The "which sealant?" debate is almost always between silicone and urethane.
Silicone Sealants |
Urethane Sealants |
|
| Wear Resistance | Moderate | High |
| Flexibility | High | Moderate |
| Adhesion | Moderate | High |
| Cure Speed | Low | High |
| Life Span | High | Low |
Joints -- some more so than others -- also need to allow a degree of movement. For example, a precompressed foam expansion joint can seal any gap weathertight, even in areas with seismic activity or frequent thermal expansion and contraction.
Picking job site-appropriate materials is a must for high-quality exterior envelope construction.
Finding the Building Envelope Products to Match
The only thing more important than understanding building envelope protection is the quality of supplies you use to create it.
Building envelope solutions exist by the thousands. Start with the five categories above, and consult with a distribution expert on the product types and job sites unfamiliar to your team.
To see the top suppliers today in each product category, visit our Manufacturers page:
