Sheathing is basically the “backing material” that can be found underneath the various layers of stucco that form the backing of residential and commercial buildings. They can be made out of wood, cement, gypsum, fiberglass and other materials.

What do you put behind stucco?

Because stucco is porous, the base—typically plywood or oriented-strand board sheathing—must have at least one layer of weather-resistant, vapor-permeable asphalt-impregnated building paper (“felt”) or plastic-based building wraps or stucco wraps.

Is sheathing required behind stucco?

STUCCO APPLICATION OVER WOOD SHEATHING

Building paper is required where stucco is applied over wood structural sheathing. Note: The International Building Code and the International Residential Code require two layers of Grade D building paper over wood-based sheathing.

Do you need plywood behind stucco?

When stucco is applied over any engineered wood sheathing, the wood sheathing must cover the entire surface which will receive the stucco. It doesn't work to only use plywood in the corners, with Styrofoam sheathing in-between. The Styrofoam isn't strong enough to support the stucco.

What are the layers of a stucco wall?

Three coat is the original stucco process, consisting of paper and wire, a scratch coat, a brown coat, and a finish, or “top” coat.

How to Install Stucco

How are stucco walls built?

Traditional stucco is applied in a three-coat process to wood-frame exterior walls. It starts with a “scratch coat” spread over metal lath attached to a house's exterior sheathing. The rough surface allows the next layer, the “brown coat,” to adhere.

How do you prepare a wall for stucco?

When working with an existing masonry or brick wall, you're going to first need to use some fresh mortar to repair any cracks that exist, then wash the wall with a power washer (or use a trisodium phosphate-water mixture and scrub it). The wall should be thoroughly wet before you apply the first coat of stucco.

What is lath for stucco?

Lath is simply the first step in the stucco process. It consists of water resistant paper, (sometimes eps foam) wire and other metal components that make up the essential “framework” for the cement to be adhered to. It attaches to the substrate and is the structure for the following coats.

Can you put stucco over plywood?

Apply two layers of grade D building paper or asphalt felt to the plywood siding. Follow with the three-dimensional drainage mat and two more layers of paper or felt. Secure stucco mesh to your walls and then apply your layers of stucco for a watertight finish.

What kind of plywood do you use for stucco?

Either softwood construction-grade exterior plywood can be used or OSB . Building codes vary from place to place, but typically call for a minimum of 3/8” of sheathing underneath stucco.

Can stucco be applied to cement board?

One finish you can use on cement boards is stucco. Extensive preparation is necessary, but once completed, you'll have a beautiful surface, suitable for further finishing by painting or left as-is for a raw plaster look.

What is stucco screed?

Weep screed is a special piece of metal flashing that runs along the bottom of walls that wicks moisture out of holes that are located at the bottom of the flashing.

How thick is stucco on an exterior wall?

The correct thickness is then 5/8 inch. Two-coat applications are only for use over solid plaster bases without metal lath. For unit masonry, that thickness is ½ inch. For cast-in-place or precast concrete, the thickness for two-coat work is 3/8 inch.

How does water get behind stucco?

Water may be getting behind the stucco through windows or other areas (possibly through improperly installed flashing). Some homeowners will deal with the mold at the surface and think that knocks the problem out.

Is there brick under stucco?

Many people purchase or inherit older homes that have layers of stucco covering an older brick and mortar exterior. For those who desire to remove the stucco to reveal the brick and mortar underneath, be forewarned that this is a huge undertaking that requires lots of time and effort.

Can water leak through stucco?

Despite what many people think about stucco walls, stucco walls are not water-resistant. As a matter of fact water actually absorbs into the stucco. In most cases, the problem with water leaking through stucco is that the building envelope has been breached.

Does stucco stick to wood?

Stucco can be applied over almost any surface. Applying stucco over your existing wood siding is a great way to cover up wood that is looking old and worn, or simply to give your home a new look.

Can you put stucco on a wood frame house?

It is easily applied to masonry walls, of brick, concrete or concrete block, but can be applied to wood-framed walls, too, with proper preparation. Done right, a stucco wall on wood sheathing is attractive and long-lasting.

How thick is stucco on a house?

Although it is called a “One Coat System,” the stucco material is usually a 3/8 inch thick coat with a 1/8 inch finish coat applied over it; thus two layers or coats.

Do you need mesh for stucco?

Two-coat stuccoing is often used when stucco is applied directly to concrete or masonry surfaces without the use of lath or wire mesh. This is because the masonry or concrete provides a very rigid stable base.

Is chicken wire used for stucco?

20 Gauge Wire (One Coat Stucco Wire):

There is really only one style and it resembles the look and thickness of traditional chicken wire. This is really the only type of wire that is used for a one coat stucco installation and the wire is made specifically for it too, so keep that in mind.

When did they stop using plaster and lath?

Lath and plaster largely fell out of favour in the U.K. after the introduction of plasterboard in the 1930s. In Canada and the United States, wood lath and plaster remained in use until the process was replaced by transitional methods followed by drywall in the mid-twentieth century.

What are the steps to stucco a house?

1. Step 1: Hang a Double Layer of Building Paper. ...
2. Step 2: Install Trim Accessories. ...
3. Step 3: Install Galvanized Lath or Netting. ...
4. Step 1: Spread the Scratch Coat. ...
5. Step 2: Apply the Brown Coat. ...
6. Step 3: Finish With the Color Coat.

What kind of paper goes under stucco?

10-Minute Building Paper is ideal for use as a weather-resistant barrier when installed behind stucco or other exterior wall cladding. GMCraft is asphalt saturated building paper.