Stucco & EIFS Glossary

Acrylic stucco

The polymer-based finish coat used on EIFS and on modern re-coats. Colour is integral to the material rather than painted on, so it does not need repainting and does not peel the way a film-forming paint does. More on this →

Backer rod

A foam rope pressed into a joint before sealant so the sealant bonds to two sides only and can stretch as the joint moves. Sealant applied without backer rod bonds on three sides and tears. More on this →

Base coat

The structural layer of a stucco or EIFS wall: a cementitious or polymer-modified coat into which the reinforcing mesh is embedded. It carries the crack resistance of the whole assembly. It must cure before the finish coat goes on — rushing this is the most common cause of a repair that crazes within a season. More on this →

Chalking

The powdery residue left on your hand after touching an aged finish, caused by UV breaking down the binder. It means the finish coat has reached the end of its service life; the wall underneath is usually still sound. More on this →

Control joint

A deliberate break cut into the stucco system so the wall has somewhere to move during freeze-thaw cycles. A wall with no control joints will crack at floor lines and above openings instead. Their absence is one of the clearest signs of a rushed original installation. More on this →

Debonding

When the stucco system loses its bond to the substrate, usually because water got behind it. The wall sounds hollow when tapped and may flex. Skim-coating over a debonded area guarantees the repair fails. More on this →

Drainage plane

The gap or drainage medium behind the insulation board that lets incidental water run down and out through flashing rather than sitting against the sheathing. The single biggest difference between 1990s barrier EIFS and what is installed today. More on this →

Eavestrough

The gutter that collects roof water. If it overflows or a downspout discharges against the wall, it will destroy a stucco exterior faster than any winter will. More on this →

Efflorescence

The white, powdery salt deposit that appears when water moves through a cementitious material and evaporates at the surface. It is not mould — it is a signal that water is travelling through the wall. More on this →

EIFS

Exterior Insulation and Finish System — a wall assembly of insulation board, a base coat with embedded fibreglass mesh, and an acrylic finish coat, installed over a water-resistive barrier on the substrate. Often called synthetic or acrylic stucco. Unlike traditional stucco it adds continuous insulation, which is why it is the most common system on GTA homes built since the late 1980s. More on this →

Elastomeric sealant

A flexible exterior sealant used at control joints, window and door perimeters and penetrations. It is the wear item on the whole wall, with a service life of roughly five to ten years in our climate. More on this →

Fascia

The vertical board at the roof edge that the eavestrough fastens to. Usually capped in aluminum at the same time as soffit work. More on this →

Fibreglass mesh

An alkali-resistant reinforcing fabric embedded in the base coat. It distributes movement across the wall instead of letting it concentrate into a single crack, and it must be lapped generously — not butted — at the edges of a repair. More on this →

Finish coat

The final, visible layer. It sets the texture and carries the colour. On acrylic systems the colour runs through the material, which is why a properly finished wall never needs painting. More on this →

Flashing

Metal or membrane detailing at sills, roof-to-wall junctions, parapets and penetrations that directs water out of the wall assembly. Most stucco water damage we are called to is a flashing problem, not a stucco problem. More on this →

Freeze-thaw cycle

One round of water freezing and thawing inside a crack or pore. Water expands about 9% when it freezes, so each cycle widens the crack slightly. Lakeside GTA areas get more cycles per winter than inland ones because temperatures hover around zero. More on this →

Hairline crack

A crack narrower than about 1 mm. Normally shrinkage and not structural. What matters is location: a hairline running diagonally from a window corner, or one with staining below it, means water is moving through the wall. More on this →

Integral colour

Colour mixed through the finish material rather than applied on top. It cannot peel or flake, and it is why an acrylic stucco exterior does not need repainting the way a painted surface does. More on this →

Map cracking

A fine web of interconnected surface cracks over a large area, usually under 1 mm wide. Caused by shrinkage or a fatigued base coat. Cosmetic on its own, but collectively a lot of small entry points for water. More on this →

Microcement

A polymer-modified cement coating applied by hand at only 2–3 mm thickness over an existing floor, wall or counter. It cures seamless, with no joints or grout lines, and adds almost no height — which is why it is used over existing tile without demolition. More on this →

Microtopping

Another trade name for microcement. The terms are used interchangeably by manufacturers; the system and the build-up are the same. More on this →

Parging

A thin cement coating applied over concrete block or a foundation wall, usually to tidy the appearance and shed water. It is not a full stucco system and has no reinforcement, which is why it spalls and sounds hollow as it ages. More on this →

Soffit

The horizontal underside of a roof overhang. Vented aluminum soffit lets the attic breathe; blocked soffit is a common cause of ice damming, which in turn drives water down stucco walls. More on this →

Stone veneer

Thin natural or manufactured stone applied as a facing over a prepared wall, usually as an accent alongside stucco. Needs its own flashing and sill details to keep water out at the transition. More on this →

Stucco repair

A localised fix: specific cracks, an impact hole or one failed section, cut back to sound material, re-meshed and texture-matched. Distinct from restoration, which treats the whole exterior. More on this →

Stucco restoration

Renewing an entire aged exterior: repairs first, then control joints and sealants, then complete elevations re-coated with a new finish. Chosen when the finish has aged out across the house rather than failing in one spot. More on this →

Substrate

Whatever the stucco system is applied to — plywood or OSB sheathing, exterior gypsum, concrete block, brick or poured concrete. Its condition decides whether a wall can be repaired or has to be rebuilt. More on this →

Texture match

Reproducing the existing surface pattern — sand, swirl, knockdown or dash — so a repair blends. Matched by sample on site before any material goes on the wall; a colour match over the wrong texture still reads as a patch from the street. More on this →

Traditional stucco

A cement-based hard-coat plaster applied in layers over metal lath. Harder and more brittle than EIFS, with no insulating value of its own. Still the right choice over masonry and on heritage work where the original profile has to be kept. More on this →

Water-resistive barrier (WRB)

The membrane between the substrate and the insulation board that stops any water getting past the finish from reaching the structure. Modern, code-compliant EIFS is water-managed: it assumes some water gets in and gives it a drainage path back out. More on this →

Still not sure what you are being quoted for? Send us the quote and a photo of the wall — (905) 973-6470 — and we will tell you what it actually covers, even if you end up hiring someone else. See also our FAQ and red flags in a stucco quote.