#Installing lath and plaster walls install
#Installing lath and plaster walls crack
#Installing lath and plaster walls windows

Image 6: Two-piece expansion joint(PVC vinyl). Hollow corner beads will soon fail due to delamination. It is imperative that the entire bead be filled with stucco in order to provide the strongest corner possible. Since the corner of the stucco membrane is often susceptible to damage from being struck, the corner bead adds reinforcement to this critical area and the metal bead will take some abuse in order to protect the Portland cement. Some manufacturers provide corner beads that can be joined with a section of wire or small nails to make a smooth transition from one section to the next. The angle on this bead is approximately 90 degrees with the expanded flanges facing each other. This will not be discussed here but is an acceptable option. Some contractors prefer to use corner reinforcement that is completely buried in the stucco. Expanded flange corner beads (Image 4) usually have 3-inch expanded flanges with a rounded solid metal or vinyl nose that partially remains exposed after the stucco application. This is followed by the installation of the last two primary accessories, corner bead and expansion joints. The next step Once the two previous beads are in place, the metal lath is installed. Image 5: One-piece expansion joint “M” type. Attachment is accomplished by nailing, stapling or screwing the bead to the framing, or through the sheathing into the framing at a spacing not to exceed 7 inches on center. This embedment will join the two into a single cohesive unit. As Image 3 shows, these beads have a “J” type configuration and are most commonly provided with an expanded flange to allow complete embedment of the stucco and lath. The smooth surface of the casing and the window frame both provides the perfect surfaces for caulking adhesion.Ĭasing beads should also be installed over moisture barriers or flashing.

By installing the casing bead next to the window and leaving approximately a 3/8-inch space between the two, a backer rod and highly flexible caulk can be applied that will allow this movement to occur without the likely occurrence of water intrusion.

#Installing lath and plaster walls crack

If stucco were applied to the edge of an aluminum window, a crack would appear after the stucco cures and shrinks, and every time the window moves due to expansion and contraction.

#Installing lath and plaster walls windows

For example, aluminum windows and Portland cement have vastly different coefficients of expansion, and therefore expand and contract quite differently. This product (shown in Image 2) serves to protect the edge of the stucco, and also provides stress relief at windows, doors and other openings where dissimilar material might come into contact with the stucco membrane.

It consists of an expanded back flange, a ground leg that matches the stucco thickness, and a 1/4-inch return lip that helps to avoid water intrusion. As the name would imply, this product is used to terminate stucco at all openings and at the top of all walls. The accessory that is generally installed next is the casing bead or plaster stop. Image 1 shows the proper application of this bead. This shrinkage results in a minor crack at the junction of the angular ground and the stucco membrane, allowing moisture to escape. All Portland cement stucco shrinks slightly when hydration and curing occurs. Should moisture make its way to the water resistant building paper, it will flow down the surface of the paper to the foundation weep screed, follow the contour of the angular surface of the ground or screed edge, and exit the cementitious membrane. While the stucco membrane is quite water resistant, it is possible over time for structural cracks or separations of the stucco at accessory edges to occur. Attachment mechanisms must be spaced no more than 7 inches on center. The attachment flange is 3 1⁄2 inches long and also serves as a flashing mechanism when the building paper is installed to cover this flange.

#Installing lath and plaster walls install

It is a good idea to install an 8- to 10-inch strip of reinforced asphalt saturated paper flashing over the sheathing behind this screed. If sheathed, the attachments must pass through the sheathing and into the framing members. This accessory is installed 2 to 6 inches above the ground (depending on whether it is paved or grade) and attached to the wooden foundation plate, or the bottom of the framing or studs in light-gauge steel frame construction. Installed at the bottom of all framed walls, it serves as one of the most important components of a redundant drainage system. The first accessory to be installed is generally the foundation weep screed.