You can pay to heat and cool the outdoors for months before a tenant reports a leak, because failed sealant can leak conditioned air long before it lets water in. Across eastern Pennsylvania, Delaware, and New Jersey, seven caulking energy-efficiency problems particularly affect the joints.
Why Mid-Atlantic Weather Wears Sealant Down
Around here, three kinds of weather patterns deteriorate exterior sealant.
Daily temperature swings tend to be hardest on seams between two different materials. Aluminum window frames and precast panels don’t expand at the same rate, so the caulk between them gets pulled and pushed as the wall heats and cools, sometimes every day in spring and fall.
Sun damage shows up mostly on south and west elevations. Years of ultraviolet light can bake a bead until it no longer gives under a thumb.
Freeze-thaw cycles mostly affect joints that are already cracked or starting to pull away. Water in a hairline gap expands when it freezes, and each cycle can widen the gap. Our post on caulking durability shows how a joint that looked tight in November can separate by March.
Rain usually doesn’t get inside unless wind drives it through a continuous path. Air gets through whenever indoor and outdoor pressure differ, which in a multistory building can be much of the workday, so gas and electric bills can rise while the walls look fine.
1. Air Leaks Around Windows and Wall Penetrations
Building air leakage is typically first evident at window perimeters, then at curtain wall joints and pipe penetrations. Suspect spots get checked by hand from a lift during caulking inspections. Lawrence Berkeley National Laboratory (LBNL) researchers estimated in 2006 that apartments and commercial buildings may carry about double the leakage of single-family houses for the same envelope area.
2. Heating and Cooling Equipment May Run Longer
In 2013, the U.S. Department of Energy (DOE) estimated that air infiltration is behind over 30% of a commercial building’s heating load. Your boilers warm that in January, and your chillers cool it in July.
Facility teams might notice rooftop units cycling more, or commercial energy costs that seem high for a mild month. Those extra hours on the heating, ventilation, and air conditioning (HVAC) system can add wear, especially on older equipment.
3. Drafts Can Lead to Tenant Complaints
The first comfort complaint often comes from a perimeter office on a leaky window wall. Somebody overrides the thermostat or plugs in a space heater, which may solve it for a day.
Raising the setpoint for the whole zone to fix one cold corner burns extra energy and can leave interior rooms too warm. When tenants on the same exposures call every winter, put the window caulking there on the next inspection list.
4. Wet Walls Can Cut Insulation Value
The DOE’s moisture control guidance lists air leaks as a main way water vapor gets into exterior walls, where it can condense and soak insulation and framing. Rain slipping past failed commercial caulking adds more.
Wet insulation won’t hold back heat as well as dry insulation. A stain under a window head or bubbling paint on the inside is often the first sign, and by then the cavity may have been underperforming for a few seasons.
5. Humidity Can Raise Dehumidification Demand
Humid July air leaking through bad joints has to be dried out by the cooling equipment. Hospitals and labs that keep humidity in a tight range may notice that load more than an ordinary office.
Oak Ridge National Laboratory (ORNL) researchers added moisture estimates to their airtightness savings calculator, since envelope leakage can carry enough water to shorten material life. The flow can reverse in heating season, when warm, moist indoor air escapes through the same gaps and condenses inside the wall.
6. Floor-to-Floor Pressure Gets Harder to Balance
In heating season, warm air rises through a tall building and escapes near the roof, while cold air is pulled in at the lobby (“the stack effect”). With failed sealant at the roofline and entrances, that loop has more holes at both ends.
You’ll hear about lobby doors that are hard to open and top-floor offices that run warm. Rebalancing dampers helps up to a point, but holding setpoints may still take more energy than the system was designed for.
7. Energy Costs Can Build Year Over Year
Infiltration doesn’t get its own line on a utility bill, so a rising baseline tends to get pinned on rate hikes or older equipment. A 2019 National Institute of Standards and Technology (NIST) paper, citing DOE figures, tied roughly 6% of the energy U.S. commercial buildings used in 2010 to envelope air leakage.
On any one building, that share can grow every year the joints are left alone. Sealant replacement targets the problem where it starts, without new windows or a mechanical overhaul.
Resealing counts as commercial air sealing, and crews can phase it by floor or elevation while tenants keep working. Owners working toward energy-efficient buildings can start with any earlier audit that flagged exterior leaks and fold the resealing into their building envelope performance plans.
Book a Free Building Assessment
Waterproof Caulking & Restoration is family-owned and has been sealing commercial buildings in Chester, Montgomery, and Delaware Counties and around Wilmington since 2010. You deal directly with the owner from first walkthrough to final inspection, and our crews schedule around tenants and clean up occupied floors before heading out.
A free building assessment can show you which joints are losing air, and you can plan resealing around your own calendar. Tenants can report drafts anonymously, which takes some of those calls off your plate.