In metal lath installation, what is the minimum side lap distance?

In metal lath installation, what is the minimum side lap distance?

• A. 1/2 inch
• B. 1/4 inch
• C. 3/4 inch
• D. 1 inch

Answer: (A)

Side lap is the overlap between adjacent strips of metal lath as they run along the wall, creating a continuous base for the plaster. The minimum overlap needs to be large enough for the plaster to bridge the joint and for the lath to act as a single unit under the plaster coat. For metal lath, that minimum is 1/2 inch. This amount provides enough surface area for the plaster to key into and for the joint to stay tight as the plaster cures and any movement occurs. A smaller overlap, like 1/4 inch, risks gaps and cracking; larger overlaps (3/4 inch or 1 inch) don’t improve bonding significantly and just add unnecessary material.

Side lap is the overlap between adjacent strips of metal lath as they run along the wall, creating a continuous base for the plaster. The minimum overlap needs to be large enough for the plaster to bridge the joint and for the lath to act as a single unit under the plaster coat. For metal lath, that minimum is 1/2 inch. This amount provides enough surface area for the plaster to key into and for the joint to stay tight as the plaster cures and any movement occurs. A smaller overlap, like 1/4 inch, risks gaps and cracking; larger overlaps (3/4 inch or 1 inch) don’t improve bonding significantly and just add unnecessary material.