ACH50
Air Changes per Hour at 50 Pascals — the standard unit a blower-door test reports. It is how many times per hour the building’s entire air volume leaks out under a 50-Pascal pressure difference. Lower is tighter.
ACH50 is the number that tells you how leaky a building is. A higher number means more air leakage and higher energy bills; a lower number means a tighter, more efficient envelope. Spray-foamed homes typically test much tighter than fiberglass-only homes because the foam is the air barrier. The specific ACH50 target for code or a rebate depends on the jurisdiction and program.
Air Barrier
A continuous layer that stops air from leaking through the building envelope. Spray foam is both insulation and an air barrier in a single application, which fiberglass and blown-in are not.
Most of the comfort and energy loss in a typical Oklahoma home comes from air leakage — conditioned air escaping and outdoor air pushing in through gaps around wires, plumbing, and where framing meets drywall. Insulation that does not air-seal (fiberglass, cellulose) lets that air move freely. Spray foam fills and seals those gaps as it cures, creating a continuous air barrier.
Air Sealing
The process of closing the gaps, cracks, and penetrations that let air leak in and out of a building. Spray foam air-seals and insulates at the same time, with no separate caulking or taping step.
Air sealing is the single biggest lever on comfort and energy bills. Every wire penetration, plumbing chase, and unsealed seam is a path for air. With fiberglass you need a separate air-sealing step (caulk, tape, foam gaskets) and it is rarely complete. Spray foam seals as it expands, which is why spray-foamed homes pass blower-door tests so consistently.
Blower Door Test
A diagnostic test that uses a calibrated fan mounted in an exterior doorway to depressurize a building and measure exactly how much air leaks through the envelope. The result is reported as ACH50.
A blower door pulls air out of the house to a set pressure, then measures the airflow needed to hold that pressure — the leakier the building, the more airflow required. It is the gold standard for verifying air-tightness, is used to confirm energy-code compliance and qualify for utility rebates, and pinpoints exactly where air is escaping. Rocking Rad offers certified blower-door testing alongside HERS ratings.
Building Envelope
The continuous physical barrier — walls, roof, floor, windows, and doors — that separates the conditioned inside of a building from the outdoors. Spray foam strengthens the envelope by acting as both insulation and air barrier.
Think of the envelope as the shell that keeps your heated or cooled air in and the weather out. A leaky envelope wastes energy no matter how good your HVAC is. The goal of any insulation upgrade is a tighter, better-insulated envelope — spray foam delivers both at once, which is why it consistently outperforms air-permeable insulation.
Closed-Cell Spray Foam
A dense, two-pound-density spray foam (about R-6.5 to R-7.0 per inch — the highest R-value per inch of any common insulation) whose cells are sealed shut. It air-seals, acts as a vapor barrier at sufficient thickness, and adds structural rigidity in one application.
Closed-cell foam is three products in one: insulation, air-and-vapor control, and structural reinforcement. Because the cells are closed and the foam resists water, it is the right choice anywhere moisture is a factor — metal buildings, pole barns, crawl spaces, basement walls, exterior walls, and rim joists. In Oklahoma metal buildings it bonds directly to the steel and keeps the surface above the dew point, which is what stops condensation. The correct thickness depends on how the building is used and how cold it gets; we spec that during a free estimate.
Condensation / Dew Point
Condensation is water forming when warm, moist air meets a surface cold enough to reach its dew point — the temperature at which air can no longer hold its moisture. It is the root cause of "sweating" metal buildings.
In an Oklahoma metal building, warm interior air hitting a cold steel roof or wall condenses and drips on whatever is stored below. Air-permeable insulation like fiberglass does not stop this because air still reaches the cold metal. Closed-cell foam bonds to the metal, keeps the surface above the dew point, and adds a vapor barrier — so warm air never contacts the cold steel and condensation stops at the source. The foam must be thick enough for the building’s use and climate, which is why thickness is spec’d per project.
Conditioned (Unvented) Attic
An attic brought inside the home’s heated-and-cooled envelope by spraying foam to the underside of the roof deck instead of on the attic floor. It seals the roofline and puts ductwork in conditioned space.
A traditional attic is vented to the outdoors and can hit extreme temperatures in an Oklahoma summer, forcing any ductwork up there to fight that heat. By spraying foam to the roof deck, the attic becomes an "unvented" or conditioned space that stays close to the temperature of the rest of the house. That takes a huge load off the HVAC system and is one of the highest-impact upgrades for most homes.
Crawl Space Encapsulation
Sealing a crawl space against outside air and ground moisture — typically closed-cell foam on the crawl-space walls combined with a vapor barrier on the floor — to bring it inside the conditioned envelope.
A vented crawl space draws in humid Oklahoma air that condenses on cool surfaces, driving moisture, musty air, and "cold floor" problems up into the house. Encapsulating with closed-cell foam on the walls and a floor vapor barrier stops that moisture, improves indoor air quality, and makes the floors above noticeably more comfortable. It is one of the most common closed-cell retrofit jobs.
Density (½-lb vs 2-lb)
How much a cured foam weighs per cubic foot. Open-cell is a half-pound (½-lb) foam — light and flexible; closed-cell is a two-pound (2-lb) foam — dense and rigid, with a higher R-value per inch.
Density is the core difference between the two foam types. The half-pound open-cell foam stays soft, expands far more, and air-seals affordably. The two-pound closed-cell foam is rigid, resists water, adds structural stiffness, and packs more R-value into each inch. Some companies cut corners with a lower-density "closed-cell" that must be sprayed thicker to perform — Rocking Rad uses a true two-pound formulation.
Drill-and-Fill
A retrofit method for insulating enclosed wall cavities without removing the drywall — small holes are drilled, insulation is injected, and the holes are patched afterward.
Drill-and-fill is useful when you want to add insulation to existing finished walls that you cannot open up. Whether it is the right approach depends on the wall and the goal — for attics, crawl spaces, and exposed surfaces like metal buildings, spray foam is applied directly to the open surface instead. We recommend the best method for your specific situation during the estimate.
HERS Rating
The Home Energy Rating System index — the industry-standard score for a home’s energy efficiency. A standard new home is set at 100; the lower the number, the more efficient the home. Spray-foamed homes typically score well below code-minimum construction.
A HERS rating is produced by a certified rater (a blower-door test is part of it) and is the number buyers, lenders, and utilities use to gauge a home’s efficiency. A lower HERS index can unlock utility rebates, energy-efficient mortgage terms, and a real marketing advantage. Because spray foam both insulates and air-seals, foamed homes consistently score better than code-minimum builds.
Ignition Barrier
A coating or covering applied over exposed spray foam to keep the foam surface from easily igniting. It is commonly required in areas people only enter occasionally, such as attics and crawl spaces.
Building codes treat exposed foam plastic as something that needs a fire-protective layer. An ignition barrier is the lighter of the two requirements and applies to limited-access spaces like attics and crawl spaces. When foam will be left exposed in those areas, an approved ignition-barrier coating is applied over the cured foam. Rocking Rad identifies whether a barrier is required and includes it in the scope so there are no surprises at inspection.
Intumescent Coating
A specially formulated coating applied over cured spray foam that swells and chars when exposed to high heat, forming a protective layer. It is how exposed foam meets ignition-barrier and thermal-barrier requirements.
Intumescent coatings are paint-like products that react to heat by expanding into an insulating char, slowing the spread of fire to the foam underneath. Beyond code compliance, they also give raw foam a cleaner, more finished, uniform appearance — a real benefit in metal buildings and commercial spaces where the insulation is visible. Coatings are applied per the manufacturer’s specifications and do not change the foam’s R-value or air-sealing performance.
New Construction
Insulating a building while it is being built, before the drywall goes up. It is the lowest-cost time to spray foam because every surface and cavity is open and accessible.
During new construction the foam is sprayed after rough-in plumbing, electrical, and HVAC but before drywall, so every penetration is sealed as the foam goes on. Closed-cell can hit code R-values in thinner wall assemblies than fiberglass, which can reduce framing and HVAC-sizing costs. Rocking Rad works directly with builders and GCs to schedule at the right point in the timeline.
Off-Gassing / Cure Time
The period right after spray foam is applied while it chemically sets and any installation odor dissipates. Spray foam is typically fully cured within about 24 hours, after which it is inert and non-toxic.
As the two foam components react and cure, the material hardens and any odor clears with proper ventilation. Our crew wears full protective equipment and ventilates the space during application, and we follow manufacturer protocols. Once cured — generally within 24 hours — the foam is chemically inert. For attic roof-deck retrofits in particular, the area stays off-limits during the cure window; we coordinate timing in advance.
Open-Cell Spray Foam
A lighter, half-pound-density spray foam (about R-3.7 per inch) whose cells are left open, so it stays soft and flexible. It expands aggressively to air-seal every crack and gap and dampens sound, but it is not a vapor barrier.
Open-cell foam expands roughly 100 times its liquid volume during cure, which is what lets it reach into irregular cavities that fiberglass batts can never fill. Because it is air-permeable to moisture vapor (not a vapor barrier) and can absorb water, we recommend it for interior applications — attics sprayed to the roof deck, interior walls, ceilings, and sound-isolation projects. It is the more affordable foam per inch and is the standard choice for most Oklahoma homes.
Perm Rating
A measure of how easily water vapor passes through a material. A low perm rating means the material slows or stops vapor — at a low enough perm, closed-cell foam functions as a vapor retarder or vapor barrier.
Perm rating is the technical basis for calling a material a "vapor barrier." Open-cell foam has a higher perm rating (vapor can pass through it), while closed-cell foam at sufficient thickness has a low enough perm rating to act as a Class II vapor retarder, and as a full vapor barrier at greater thickness. This is why closed-cell is specified where moisture control matters.
R-Value
A measure of how well an insulation resists heat flow — the higher the R-value, the better it slows heat transfer. Open-cell foam is about R-3.7 per inch; closed-cell foam is about R-6.5 to R-7.0 per inch.
R-value alone does not tell the whole story. A fiberglass batt may show a similar number on paper, but the moment air moves through the gaps around it, that rated value no longer reflects real-world performance. Because spray foam also air-seals, its rated R-value is much closer to its actual in-place performance — no wind-washing, no gaps, no settling over time.
Retrofit
Adding or upgrading insulation in an existing building, as opposed to insulating during new construction. Most of Rocking Rad’s attic and metal-building work is retrofit.
Retrofitting focuses on the highest-impact areas you can reach without major demolition — attics, crawl spaces, rim joists, and the interior surfaces of metal buildings. It delivers the comfort and energy benefits of spray foam to a home or building that was originally insulated with fiberglass or left bare. New construction is cheaper per square foot because every surface is open, but a well-planned retrofit pays back fast.
Spray Rig
The mobile equipment system — proportioner, heated hoses, and spray gun, usually trailer- or box-truck-mounted — that meters, heats, and combines the two foam components at the spray gun.
Spray foam is not a canned product; it requires a calibrated rig that precisely meters the two liquid components, heats them to the right temperature, and mixes them at the gun where they react and expand. A high-output professional rig is what lets a crew complete a typical residential attic in a day. Proper rig calibration and ambient conditions during install directly affect foam quality, which is why this is professional, not DIY, work.
Thermal Barrier
A fire-protective layer required over spray foam in occupied spaces — it gives the foam a fire-resistance rating. Drywall is the most common thermal barrier; an approved intumescent coating is used where the foam stays exposed.
A thermal barrier is the more robust of the two fire-protection requirements and applies to living and working spaces. In a finished home the drywall itself usually serves as the thermal barrier, so no extra coating is needed. But where the foam stays visible — garages, workshops, metal buildings, commercial spaces — an approved intumescent thermal-barrier coating is applied. We handle insulation and coating as one project so the two layers are compatible and documented for inspection.
Thermal Bridging
Heat taking a shortcut through a conductive part of the structure — like a wood stud or steel framing — that bypasses the insulation. Spray foam reduces thermal bridging by sealing continuously around framing members.
In a framed wall, the studs themselves conduct heat far faster than the insulated cavities between them, so heat "bridges" across the framing. Metal buildings are even worse because steel is highly conductive. Continuous spray foam — especially closed-cell sprayed across the framing and metal surface — cuts down these bridges and evens out the temperature across the whole envelope.
Two-Component Foam (A-side / B-side)
Spray foam is made from two liquid chemicals — the A-side (isocyanate) and the B-side (resin blend) — that are kept separate until they combine at the spray gun, where they react and expand into solid foam.
Keeping the two sides separate until the gun is what makes spray foam a precise, on-site product: the A-side and B-side are metered in the correct ratio, heated, and mixed only at the moment of application, where they react, expand, and cure. The exact blend determines whether the result is open-cell or closed-cell. This two-component chemistry is also why professional equipment and trained applicators are essential to a sound installation.
Vapor Barrier / Vapor Retarder
A material that blocks or slows water vapor from moving through an assembly. Closed-cell spray foam at sufficient thickness acts as a vapor retarder, and as a vapor barrier at greater thickness; open-cell foam does not.
Controlling vapor is how you prevent condensation and the mold and rot that follow it inside walls, crawl spaces, and metal buildings. Because closed-cell foam combines an air seal and a vapor barrier in one application, it can replace separate poly sheeting in many assemblies. The exact thickness needed to hit vapor-barrier performance depends on the application — we spec it per project.
Yield
How many board feet of cured foam a set of material produces. Yield is affected by foam type, application thickness, ambient temperature, and how well the rig is calibrated.
Yield matters because it ties the raw material to the actual coverage you get on a job. Open-cell foam expands far more than closed-cell, so it yields more board feet per set of material — part of why it costs less per inch. Cold or hot install conditions and rig settings can change yield, which is one reason on-site assessment and professional equipment matter for a quality result.
