Metal Lath & Security Mesh

Metal lath and security mesh are both expanded steel, made for opposite jobs. Diamond mesh lath holds plaster, stucco and stone veneer, while flattened security mesh sits behind the finish board to slow forced entry through walls and ceilings.

Tie Wire

Thin, soft annealed 18 ga galvanized steel wire, cut to 27″ and 42″ lengths. It ties furring channel to carrying channel at every crossing, ties metal lath to its channels and laps, and holds joints to the lath. It is a tying wire, not a hanger.

Metal Lath

Galvanized diamond mesh: a light steel sheet opened into many small diamonds. Fastened to framing, it is the base for cement plaster (stucco), interior plaster, adhered stone veneer and tile mortar beds; the first coat pushes through the openings and hardens into a solid key.

Security Mesh

Flattened expanded steel mesh screwed to the studs behind the gypsum board. It adds a continuous steel layer inside the wall that helps it resist forced entry, in pharmacies, banks, cash offices, server rooms, records rooms, retail and demising walls.

More Products

Lath or mesh: which one you need

The two look similar in the bundle, but they go in different places in the wall.

	Metal lath	Security mesh
Job	Holds plaster, stucco, stone veneer, tile beds	Adds a steel layer that resists cut-through
Where it goes	On the surface, under the plaster	Inside the wall, behind the board
Sizes	1.75 lb/yd², 27" × 96"; 2.5 lb/yd², 27" × 97"	3/4" #9F and 1-1/2" #9F, 4' × 8'
Steel	G60 galvanized diamond mesh	Flattened expanded steel, one piece

Choosing a lath weight

The plaster specification decides, but the usual split is simple:

2.5 lb/yd²: exterior stucco, adhered stone veneer, studs at 16" on centre.
1.75 lb/yd²: interior plaster, tile mortar beds, small areas and repairs on closer supports.

Lath is fastened with the long way of the diamond across the supports, lapped at sides and ends, and wire-tied between supports to ASTM C1063.

Where security mesh is used

Security mesh turns an ordinary partition into a harder barrier without changing how it looks. Typical rooms:

pharmacies, banks and cash offices,
server and records rooms,
retail stockrooms and demising walls.

Sheets are screwed to every stud and track, usually full height from slab to structure. 3/4" #9F has more steel per square foot; 1-1/2" #9F is lighter.

Common questions

Quick answers on weights and sizes.

1.75 lb or 2.5 lb metal lath?

2.5 lb is the usual choice for exterior stucco and 16" support spacing. 1.75 lb suits lighter interior plaster at closer spacing.

What does 3/4" #9F mean?

3/4" is the nominal opening, #9 the strand gauge, and F means the strands are flattened.

Can security mesh go in a fire-rated wall?

Fire-rated walls must still follow their tested design.