Stucco covers a range of very different systems, and the differences matter more than most homeowners realise. Traditional cement stucco and synthetic stucco perform differently, are installed differently, and carry different risks.
This guide covers the two main types, the lath that sits behind them, and the finishes and paints available, so you can tell which one you have or which one you are being quoted.
Various Types of Stucco
Mainly there exist two common types of stucco, such as:
- Traditional Stucco
- Synthetic Stucco
Traditional Stucco
Traditional stucco is Portland cement, sand, lime, and water. The cement gives it strength; the lime makes it more workable and slightly more forgiving of movement. Some mixes add glass fibers or acrylic modifiers to improve crack resistance. It is applied in three coats over lath: a scratch coat, a brown coat, and a finish coat, with curing time between each.
A cement-rich mix is hard and brittle, which is why lath matters: it holds the stucco together as the wall moves. Correctly installed traditional stucco lasts decades, and in Colorado you should expect some hairline cracking over time from freeze-thaw cycling and soil movement. That is normal and repairable rather than a failure.
Synthetic Stucco
Synthetic stucco, usually sold as EIFS (Exterior Insulation and Finish System), is a very different assembly. It uses an acrylic-based finish over foam insulation board rather than a cement mix over lath, which is why it looks similar and behaves nothing alike.
The acrylic finish is more flexible than cement stucco, so it resists surface cracking better. The critical distinction is drainage. Early barrier EIFS had no drainage plane behind the foam, and water that got in behind it had nowhere to go, which produced widespread moisture damage and litigation through the 1990s. Modern drainage EIFS incorporates a water-resistive barrier and a drainage cavity specifically to address that.
Stucco Lath Types
Nowadays, a wide range of wires is purposely used in the stucco. So, let’s discuss these different stucco lath types one by one.
Three-Coat Stucco Wire
17 Gauge wire or three-coat stucco wire is a rather strong type of stucco lath that is used primarily in a three-coat stucco system. The lath should be fully embedded in the scratch coat rather than sitting against the sheathing, so the stucco keys around it. Furred lath holds the wire off the substrate to allow that. Three-coat lath is normally galvanized for corrosion resistance.
One Coat Stucco Wire
20 Gauge wire or one coat stucco wire is primarily used in those places where thick coating is not required. One coat stucco wire has a small opening and is a malleable one.
High Rib Lath
High rib lath is a famous stucco lath type as this one is used on ceilings. The design makes sure that the plaster stays in place and that there are minimum chances of possible fallout. In general, high rib lath also resemble an expanded metal lath but it is rather of rigid structure.
Expanded Metal Lath
Expanded metal lath is commonly used in areas where there are patches, transitions, or uneven surfaces. But this one has a smaller pattern. The sheets might not come pre-furred but you can choose to opt for the furred ones as well.
Three coating types are commonly used on stucco:
Usually, there are given below types of paints that stucco can withstand.
- Elastomeric: thick and flexible, and able to bridge hairline cracks. The trade-off is that it is close to vapor-impermeable, so it can trap moisture in a wall that is already wet.
- Masonry: breathable and formulated for cementitious surfaces, which suits traditional stucco well.
- Acrylic: the general-purpose option, breathable and available in the widest color range.
Which one suits depends on the condition of the existing stucco and whether the wall has a moisture history. We can advise on that before you specify.
Different Stucco Siding Types
As we have discussed above, in addition to different stucco types, there also exists a plethora of stucco finishes or stucco siding types that one needs to know.
- Float or sand
- Dash
- Lace and skip
- English
- Santa Barbara
- Cat face
- Smooth texture
- Worm
The Bottom Line
If you already have stucco, the useful thing to establish is which type it is, since traditional and synthetic need different repair approaches and carry different risks. If you are specifying new, traditional cement stucco over correctly installed lath is what we recommend for most Colorado homes.
Our hard coat versus EIFS comparison covers the difference in more detail, or get in touch and we will look at what you have.
