B

Building Envelope

The physical barrier between the interior and exterior of a building — includes walls, roof, windows, and foundation. A properly sealed building envelope prevents moisture intrusion, air leakage, and heat transfer. Failures in the building envelope are among the most common sources of water damage in commercial properties.

C

Caulking

A flexible sealant applied to joints, gaps, and seams around windows, doors, expansion joints, and penetrations to prevent water and air infiltration. Caulk degrades over time due to UV exposure, thermal cycling, and building movement, and should be inspected regularly.

Concrete Restoration

The process of repairing deteriorated, spalled, cracked, or delaminated concrete to restore structural integrity and surface protection. Methods include patching with repair mortars, epoxy injection for cracks, and application of protective coatings.

Crystalline Waterproofing

A waterproofing system that uses crystalline compounds to penetrate concrete and react with moisture and free lime to form insoluble crystals. These crystals permanently block pores and micro-cracks from within the concrete matrix, providing a self-sealing waterproofing effect.

D

Deck Coating

A waterproofing membrane applied to elevated horizontal surfaces such as parking decks, balconies, walkways, and plaza decks. Deck coatings must be flexible enough to accommodate thermal expansion and contraction while providing durable, slip-resistant protection.

Drainage Plane

A system of materials and strategies designed to direct water away from the building structure. A proper drainage plane prevents moisture from becoming trapped behind cladding or within wall assemblies.

Drip Edge

A metal flashing installed at roof edges that directs water away from the fascia board and into the gutter. Properly installed drip edges prevent moisture infiltration at the most vulnerable edges of the roof.

E

Efflorescence

White, powdery mineral deposits that appear on concrete or masonry surfaces when water carries soluble salts to the surface and evaporates. While efflorescence itself is not structurally damaging, it is a reliable indicator of active moisture movement through the substrate.

Elastomeric Coating

A rubber-like coating applied to roofs and exterior walls that can stretch and return to its original shape without cracking. Elastomeric coatings are widely used in Houston due to their ability to bridge minor cracks, reflect UV radiation, and withstand the expansion and contraction caused by extreme heat cycles.

EPDM (Ethylene Propylene Diene Monomer)

A synthetic rubber roofing membrane commonly used on flat or low-slope commercial roofs. EPDM is valued for its durability, flexibility in cold temperatures, and resistance to UV radiation and ozone. It is one of the most common low-slope roofing materials in commercial construction.

Epoxy Injection

A repair method used to fill and seal cracks in concrete structures. A low-viscosity epoxy resin is injected under pressure into the crack, bonding both sides and restoring the structural integrity of the concrete element.

Expansion Joint

A planned gap in a building structure that allows independent movement of adjacent sections due to thermal expansion, contraction, seismic activity, or settlement. Expansion joints must be sealed with a flexible sealant or cover assembly that accommodates movement while preventing water infiltration.

F

Flashing

Thin pieces of sheet metal or other waterproof material installed at intersections and transitions on a roof — around chimneys, vents, skylights, and parapet walls — to prevent water from infiltrating at these vulnerable points. Failed flashing is one of the most common causes of roof leaks.

M

Modified Bitumen

A type of asphalt-based roofing membrane reinforced with polyester or fiberglass. Modified bitumen is applied in multiple plies and offers improved flexibility, strength, and waterproofing performance compared to traditional built-up roofing.

Moisture Intrusion

The unwanted entry of water or water vapor into a building structure. Moisture intrusion can result from roof leaks, failed window seals, improper flashing, hydrostatic pressure, condensation, or degraded waterproofing. Left unaddressed, it leads to mold growth, structural deterioration, and increased repair costs.

N

Negative-Side Waterproofing

Waterproofing applied to the interior side of a structure where water pressure is pushing against it. Used in below-grade areas such as basements and tunnels. Crystalline waterproofing products are often used on the negative side.

P

Parapet Wall

A low wall along the edge of a roof, terrace, or balcony. Parapet walls are a common source of water infiltration when their caps, copings, or base flashings are not properly sealed and maintained.

Positive-Side Waterproofing

Waterproofing applied to the exterior face of a structure, on the side where water is approaching. This is the preferred method as it keeps water entirely out of the structural assembly, but requires excavation for below-grade applications.

Pressure Washing

A cleaning method using high-pressure water spray to remove dirt, mold, mildew, paint, and surface contaminants from concrete, masonry, and building exteriors. In Houston's humid climate, regular pressure washing helps prevent biological growth that can accelerate surface deterioration.

R

Rebar (Reinforcing Bar)

Steel bars embedded in concrete to increase its tensile strength. When the concrete cover over rebar cracks or carbonates, moisture reaches the steel and causes it to rust. The expanding rust exerts outward pressure that causes further spalling and delamination of the concrete cover.

Roofing Restoration

The process of extending the life of an existing roof system through cleaning, repair, and the application of a new protective coating or membrane. Restoration is typically significantly less expensive than full roof replacement and can add 10 to 15 years of service life when properly executed.

S

Sealant

A flexible material applied to joints, seams, and penetrations to prevent water, air, or contaminants from passing through. Unlike caulk, which is typically used for interior applications, sealants are formulated to withstand outdoor exposure, UV radiation, and building movement.

Spalling

The chipping, flaking, or peeling of a concrete surface, typically caused by freeze-thaw cycles, corrosion of embedded reinforcement, or the use of deicing salts. Spalling exposes the internal structure of the concrete to further moisture and chemical attack.

T

TPO (Thermoplastic Polyolefin)

A single-ply white roofing membrane that is heat-welded at seams. TPO is valued for its energy efficiency (highly reflective surface), resistance to UV and chemicals, and competitive cost. It is among the most installed commercial roofing systems in the United States.

W

Waterproofing

The process of making a structure resistant to the ingress of water under specified conditions. Waterproofing systems range from surface-applied coatings and membranes to integral admixtures and drainage systems. Effective waterproofing is critical for below-grade structures, roofs, decks, and any building element exposed to standing water or hydrostatic pressure.

Weep Holes

Small openings in masonry walls, window frames, and retaining walls designed to allow accumulated moisture to drain out of the wall assembly. Blocked weep holes cause water to accumulate within the wall, leading to moisture damage and structural deterioration.

Wet Glazing

A method of sealing the joint between a window frame and its glazing (glass) using a flexible sealant. Over time, wet glazing seals degrade due to UV exposure, thermal movement, and aging. Failed wet glazing is a leading cause of window leaks in commercial buildings.

Building & Waterproofing Glossary