Ecologic Guides · Vocabulary

The spray foam glossary: every term, plainly

By Ecologic Spray Foam · Sources: CCMC, CAN/ULC, NBC 2020, manufacturer TDS · Updated July 2026

What this page is

Spray foam quotes, listings and inspection reports run on a vocabulary most homeowners meet for the first time mid-project: LTTR, permeance, SQAP, off-ratio, thermal barrier. This page defines 32 of those terms in plain language, alphabetically, with the actual numbers attached where a number exists. The definitions match the standards and listings the industry works from: CCMC evaluations, the CAN/ULC S705 and S770 standards, and NBC 2020. Where one of our guides or service pages covers a term in depth, the definition links to it. Read it straight through in ten minutes, or keep it open beside a quote and look things up as they come at you.

Sources: CCMC 14133-L · CAN/ULC standards · NBC 2020 · manufacturer TDS

A – B

AHJ (authority having jurisdiction): The office or official with legal authority to enforce the building code on your project, typically the municipal building department and its inspectors. In Winnipeg, permits and inspections run through the City; rural Manitoba projects answer to their municipality. When a page on this site says the AHJ decides, it means their interpretation wins.
Air barrier: A material or assembly that stops air from leaking through the building envelope. The code limit for an air-barrier material is an air permeance of 0.02 L/s·m² at 75 Pa; the closed-cell foam we install measures 0.002 L/s·m² at 1 inch, ten times tighter than the limit. Air leakage moves more heat than conduction in most older Manitoba homes.
Blowing agent: The gas that expands liquid foam and, in closed-cell products, stays sealed in the cells where it improves insulating performance. Older foams used HFC blowing agents with a global warming potential around 1,030 times CO2; current foams use HFOs rated at 1. See the HFO vs HFC guide for the full story.
Board foot: The unit spray foam is priced in: one square foot of area covered one inch thick. A 100 square foot wall sprayed at 2 inches is 200 board feet. Prairie-market installed pricing typically runs $1.35 to $2.50 per board foot.

C – D

CCMC: The Canadian Construction Materials Centre, part of the National Research Council, which evaluates building products and publishes the listings that inspectors and rebate programs rely on. The closed-cell foam we install is CCMC 14133-L. If a product claim matters, the CCMC listing is where to check it.
Closed-cell foam: 2lb medium-density spray polyurethane foam whose cells set sealed, trapping the blowing agent. It insulates at R-5.3 at 1 inch rising to R-24.1 at 4 inches (LTTR), qualifies as an air barrier at 1 inch and a vapour barrier at 2, and cures rigid and moisture-tolerant. The default choice against concrete and steel in Manitoba.
CUFCA: The Canadian Urethane Foam Contractors Association, the certification and quality-assurance body named on our foam's CCMC listing as its SQAP provider. CUFCA trains and licenses installers, who carry photo-ID licences presentable on request, and runs third-party site audits that building officials can request.
Daily work record: The job log the installation standard CAN/ULC-S705.2 requires the installer to keep: product and batch numbers, substrate and ambient conditions, pass thicknesses and density checks for each day of spraying. It is the paper trail proving the foam on your wall was installed within specification. Ask to see it.
Dew point: The temperature at which the water vapour in air condenses to liquid. Every wall in a Manitoba winter has a plane somewhere inside it at dew-point temperature; good assembly design keeps moisture-sensitive materials and moist air away from that plane. Much of foam's job is keeping warm indoor air from ever reaching a cold surface.

E – H

Effective R-value: The thermal performance of a whole assembly once framing and other thermal bridges are counted, as opposed to the label value of the insulation alone. NBC 9.36 sets its targets in effective terms. A 2x6 wall of R-19 batts performs well below R-19 once the studs are averaged in; the R-values guide works the math.
Flame-spread index: A measure of how fast flame travels across a material's surface in a standard tunnel test, CAN/ULC-S102 in Canada. Lower is better. Spray foams are tested and rated, but every plastic foam remains combustible and must be covered as the code directs.
Flash-and-batt (hybrid): An assembly combining a thin pass of closed-cell foam for air-sealing and vapour control with cheaper batt or blown insulation for the remaining R-value. Done right it buys most of foam's benefits at lower cost; the foam-to-batt ratio needs checking under NBC 9.25.5.2 so condensation cannot form on the foam face.
HFO / HFC: Two generations of blowing agent. HFCs (hydrofluorocarbons) persist in the atmosphere and carry global warming potentials near 1,030; Canada prohibited HFC-blown foam manufacture on January 1, 2021. HFOs (hydrofluoroolefins) break down in days to weeks and rate a GWP of 1. Current Canadian closed-cell foam is HFO-blown.
HRV: Heat recovery ventilator: a unit that exchanges stale indoor air for fresh outdoor air while recovering most of the heat. Manitoba requires HRVs in new homes, and the code's insulation targets assume one. The tighter a house gets, through foam or otherwise, the more the HRV matters.

I – L

Ignition barrier: A lighter grade of protective covering permitted over foam in spaces entered only for service, such as some attics and crawl spaces, where a full thermal barrier is not required. What qualifies depends on the space and the AHJ. The thermal barriers guide maps the requirements.
Intumescent coating: A paint-like coating that swells into an insulating char when exposed to fire, slowing flame spread and heat transfer to what is underneath. We apply DC 315, a coating tested for use as a protective covering over spray polyurethane foam, where an assembly calls for one.
Isocyanate (MDI): The A-side chemical of two-component spray foam, reactive during spraying and the reason installers wear supplied-air respirators and occupants stay out until cure. Once fully reacted into polyurethane it is inert. The safety guide covers exposure, curing and re-entry timing.
LTTR: Long-term thermal resistance: the R-value a closed-cell foam is predicted to hold after five years in service, measured under CAN/ULC-S770. It is the design value Canadian codes and Efficiency Manitoba accept, with aging already accounted for. Fresh-sprayed and marketing R-values run higher; LTTR is the number to compare quotes on.

O – P

Off-ratio foam: Foam sprayed with the two components out of their intended balance, usually from equipment or temperature problems. It cures soft or brittle, can smell fishy, and is behind most spray foam horror stories. Certified installers verify ratio and density daily and log the results; the fix for bad foam is removal, which is why prevention is the job.
Open-cell foam: 0.5lb low-density spray foam whose cells open as they form, leaving a soft, air-filled, vapour-open material. It insulates at R-3.5 per inch (ASTM C518), air-seals at full stud depth, and is rated STC-52 for wall sound control. In Manitoba open-cell needs a separate vapour barrier such as 6-mil poly.
Pass (lift): One layer of foam sprayed in a single application. The installation standard limits how thick each pass can be, because curing foam generates heat; installers build final thickness in multiple passes with cooling time between them. Pass thicknesses belong in the daily work record.
Perm / permeance: The measure of how readily water vapour diffuses through a material, expressed in Canada in ng/(Pa·s·m²). The code's vapour-barrier threshold is 60, roughly equal to one US perm. Lower numbers mean tighter vapour control.

R – S

R-value / RSI: The standard measures of resistance to heat flow; higher means better insulation. RSI is the metric unit Canadian codes use and R is the imperial one: multiply RSI by 5.678 to convert. The R-values guide explains how foam values are tested, aged and quoted.
Rim joist: The band of framing where the floor structure meets the foundation wall, the leakiest and coldest framing detail in most Manitoba houses. Its geometry defeats batts and poly; closed-cell foam air-seals and insulates it in one operation. Our rim joist page covers the assembly.
S705.1 / S705.2: The two CAN/ULC standards governing 2lb closed-cell spray foam in Canada: S705.1 sets what the material must be, and S705.2 sets how it must be installed, covering substrate conditions, pass thickness, density verification and documentation. A quote that cites them is a quote you can hold to.
S770: The CAN/ULC standard test method behind LTTR, the long-term thermal resistance of closed-cell foams. Editions matter: the same foam rates R-12 at 2 inches under the 2003 edition and R-11.1 under the current 2015 edition. Always ask which edition an R-value comes from.
SQAP: Site quality assurance program: the third-party regime a CCMC spray foam listing requires, covering installer certification, daily self-testing and random field audits. For our foam the designated SQAP provider is CUFCA, named on the listing itself.

T – V

Thermal barrier: The fire-protective layer, most commonly 12.7 mm gypsum drywall, that the code requires between foam plastic insulation and occupied space, buying escape time by keeping fire off the foam. Where it is required and what qualifies is the subject of the thermal barriers guide.
Thermal bridging: Heat bypassing insulation by conducting through the solid materials around it, chiefly wood and steel framing. Framing can occupy roughly a quarter of a wood-frame wall, which is why codes now set targets in effective R-value rather than label R-value.
Time-to-occupancy: How long occupants stay out after spraying while the foam cures and the space is ventilated. For the closed-cell foam we install, the CCMC listing sets 25 hours for a ventilated, segregated retrofit area; our open-cell foam passes its VOC test at 24 hours. New-construction timing differs; the safety guide has details.
Vapour barrier: A material with water-vapour permeance of 60 ng/(Pa·s·m²) or less, required on the warm side of Manitoba assemblies to keep indoor moisture from diffusing into cold framing. Polyethylene sheet is the familiar version; closed-cell foam qualifies at 2 inches, with a design permeance of 39 on its CCMC listing.
VOC: Volatile organic compounds: the airborne chemicals a curing foam gives off, which taper as cure completes. Canadian spray foams are tested under CAN/ULC-S774 to set re-occupancy timing; both foams we install pass at roughly a day. Persistent odour long after cure is not normal and warrants a call.

Sources

Where these definitions come from

CCMC evaluation 14133-L: the National Research Council listing for the closed-cell foam we install, including permeance, density, SQAP and time-to-occupancy values used above.
CAN/ULC standards S705.1 and S705.2 (material and installation), S770 (LTTR test method) and S774 (VOC emissions).
CUSE Grizzly Gold technical data sheet, 2024 edition, and Grizzly 005 TDS, 2021 edition: R-value ladder, air permeance, open-cell properties and blowing agents.
NBC 2020: Section 9.25 (vapour and air barriers), Section 9.36 (effective R-value targets), as adopted by Manitoba Regulation 78/2023.
Efficiency Manitoba, Home Insulation Rebate: the CCMC-LTTR requirement referenced under LTTR.

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