![metal lath metal lath](https://www.buildersmetalwork.com/image/catalog/products/Mesh/expanded_metal_lath_sheet1.png)
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.
METAL LATH 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.
METAL LATH 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.
![metal lath metal lath](https://www.wconline.com/ext/resources/issues/2014-January/WC0114-FT3-metallath-p1SL.jpg)
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.
METAL LATH 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.
![metal lath metal lath](https://www.myhandymans.com/wp-content/uploads/2020/01/Expanded-metal-lath.jpg)
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.
![metal lath metal lath](https://www.metalriblath.com/img/carousel-1.jpg)
This includes metal wire mesh or expanded metal that is applied to a wood or metal framework as matrix over which stucco or plaster is applied, as well as wallboard products called gypsum or rock lath.Image 3: Casing bead expanded flange. Lath has expanded to mean any type of backing material for plaster. Install lath with a minimum 1” overlap on horizontal and vertical seams. The surface should feel rough as you rub your hand upward. This will make the lath angle down against the wall forming little cups that will help in catching the mortar for the scratch coat.Įxpanded, galvanized, metal lath to each stud 6” on center-vertically, penetrating the studs at least one inch. Said of metal lath or welded wire fabric having some means of spacing it from a wall when plaster, stucco, or concrete is applied to the fabric, the space makes it possible to key, 8 the applied material to the metal lath or welded wire fabric.Īdditionally, which direction do you install metal lath? The lath should be applied horizontally Surface should be rough as you rub your hand upward. Paper backed lath is often used in this type of application as a bond breaker. Self- Furred Diamond Mesh Lath is secured to masonry surfaces with hardened concrete nails and power driven fasteners at the furring dimples.