General Specifications of Paper & Mesh for a Stucco Ceiling

General Information

• Stucco is a plaster material made from cement, sand and other materials, and it is used for interior and exterior treatments. When applying stucco to a ceiling, wooden lath is traditionally installed to the ceiling before the stucco is added. Some installers of stucco ceilings forgo lath and apply the stucco directly to drywall. However, if you have a nontraditional ceiling, such as brick or tile, or you want to add a fire-resistant barrier, metal mesh sheeting or mesh tape may be used. Metal lath mesh also provides better adhesion than wooden lath.

Mesh Sheeting

• Diamond mesh lath is used for stucco ceilings. This material is typically 16-gauge and sold in sheets that are 27 inches by 96 inches. Applicable weights include 1.75 pounds per square yard, 2.5 pounds per square yard and 3.4 pounds per square yard. Lath is attached to gypsum board. The ends of the mesh lath are lapped by 1 inch and the sides are lapped by 1/2 inch. Masonry fasteners hold the lath in place every 6 inches.

Mesh Tape and Corner Bead

• When applying a thin layer of stucco, gypsum board and mesh tape may be used. Gypsum board is hung in a manner similar to drywall installation, and mesh tape is added over the joints. The tape may come with an adhesive on the back, or you may need to staple it in place with 1/4-inch staples. Mesh corner bead is also added with 1 1/4-inch flanges.

Paper

• If you want to add a water-resistant barrier, you can use paper-backed lath. The paper should meet federal specifications and have the label and notations of UU-B-790A, Style 2, Grade D. This asphalt-saturated paper is provided as a backing for the mesh lath, and it is offset by 1 inch on one side and on one end.

Considerations

• The specifications for your mesh lath may be determined by local building codes. Local building codes also dictate the lap minimums for lath use.