Typically, EIFS is a layer of foam laminated or mechanically fastened to a substrate with mesh and a polymer base coat over the top of the foam – and then an acrylic finish over the top of everything.

1. portland cement

2. lime

3. fibers

4. additives

5. and aggregates – usually around 70% of the mix

Conventional – or three-coat – stucco will have a weather barrier of either from asphalt impregnated or synthetic building wraps or sprayed or rolled air and moisture barriers. Over that will be expanded or woven wire lath then a scratch and brown coat application of mortar.

AMX 740 FBC (Fiber Base coat) is the Amerimix product used in three-coat stucco systems. The finish over the top can be paint, colored stucco, or synthetic and elastomeric coatings.

In the early 1970’s one-coat systems contained fibers and colored pigments in a single coat – it was a true one-coat application. The color tended to be washed out and inaccurate because the use of field mixed sands and the fibers would show in some areas as well.

By the 1980’s a topcoat of colored stucco finish was being used over one-coat stucco and the appearance of the finished product was greatly enhanced. Many people started calling that system “two-coat” but today just as many people still use the term “one-coat” to describe the two-coat system.

These are terms associated with the one-coat and three-coat systems described above. They are described as hard coat systems because the base coats used for these wall assemblies are formulated with portland cement/lime or masonry cement as the ‘backbone’ of the product.

EIFS as described above are synthetic systems – highly modified portland cement/fine sand, if used at all – is a very small component of the materials used to construct the wall. EIFS wall assemblies depend on additional components such as fiberglass mesh reinforcement to add durability to wall surfaces.

Water barrier and water management are also terms associated with stucco systems.

Aggregates – also called plaster sand when used for stucco – give cement plaster the body to be able to work in three dimensions. When the aggregates are graded and proportioned correctly – and combined with portland cement/lime or masonry cement – the matrix cures into a hard and durable wall.

Properly graded and proportioned aggregates save you money because they provide the maximum yield for a stucco base coat.

The applicator has sand piles delivered to the jobsite along with pallets of cement – they can blend together in a mixer.

As soon as the scratch coat material is firm enough to support the weight of the brown coat layer. It must be applied before 24 hours or you will have to wait an additional 28 days.

Yes.

There are three general guidelines for every stucco system: First there are broad national specifications to consider: EIFS and conventional stucco applications are part of the International Building Code (IBC).

Next there are specialty codes (fire & energy) and ASTM standards that apply.

And finally, one-coat stucco systems – like Amerimix 740 Fiber Base Coat – will have an IAPMO report as an application guideline. Amerimix’s IAPMO Report is #427.

Stucco is a highly versatile material, able to be used in many applications, regions and over several substrates.

However, there are specific temperature ranges for the application of portland/lime and masonry cement stucco base coats and finishes, with particularly high temperatures requiring specialized blends such as Amerimix AMX 750.

Yes, typically after 7 days for latex based paint, but contact the manufacturer of the paint for their recommendations.

No, lathe would be required for proper mechanical bond.

28 days.