International Building Code Section 2510


International Building Code 2510.1

General. Exterior and interior cement plaster and lathing
shall be done with the appropriate materials listed in Table
2507.2 and Chapter 35.

International Building Code 2510.2

Weather protection. Materials shall be stored in such a
manner as to protect such materials from the weather.

International Building Code 2510.3

Installation. Installation of these materials shall be in
compliance with ASTM C 926 and ASTM C 1063.

International Building Code 2510.4

Corrosion resistance. Metal lath and lath attachments
shall be of corrosion-resistant material.

International Building Code 2510.5

Backing. Backing or a lath shall provide sufficient
rigidity to permit plaster applications.

Support of lath. Where lath on vertical surfaces
extends between rafters or other similar projecting members,
solid backing shall be installed to provide support for
lath and attachments.

Use of gypsum backing board.

Use of gypsum board as a backing board.
Gypsum lath or gypsum wallboard shall not be used as a
backing for cement plaster.
Exception: Gypsum lath or gypsum wallboard is permitted,
with a water-resistive barrier, as a backing for
self-furred metal lath or self-furred wire fabric lath
and cement plaster where either of the following conditions
occur:
1. On horizontal supports of ceilings or roof soffits.
2. On interior walls.

Use of gypsum sheathing backing. Gypsum
sheathing is permitted as a backing for metal or wire fabric
lath and cement plaster on walls. A water-resistive
barrier shall be provided in accordance with Section
2510.6.

Backing not required. Wire backing is not
required under expanded metal lath or paperbacked wire
fabric lath.

International Building Code 2510.5.1

Support of lath. Where lath on vertical surfaces
extends between rafters or other similar projecting members,
solid backing shall be installed to provide support for
lath and attachments.

International Building Code 2510.5.2

Use of gypsum backing board.

Use of gypsum board as a backing board.
Gypsum lath or gypsum wallboard shall not be used as a
backing for cement plaster.
Exception: Gypsum lath or gypsum wallboard is permitted,
with a water-resistive barrier, as a backing for
self-furred metal lath or self-furred wire fabric lath
and cement plaster where either of the following conditions
occur:
1. On horizontal supports of ceilings or roof soffits.
2. On interior walls.

Use of gypsum sheathing backing. Gypsum
sheathing is permitted as a backing for metal or wire fabric
lath and cement plaster on walls. A water-resistive
barrier shall be provided in accordance with Section
2510.6.

International Building Code 2510.5.2.1

Use of gypsum board as a backing board.
Gypsum lath or gypsum wallboard shall not be used as a
backing for cement plaster.
Exception: Gypsum lath or gypsum wallboard is permitted,
with a water-resistive barrier, as a backing for
self-furred metal lath or self-furred wire fabric lath
and cement plaster where either of the following conditions
occur:
1. On horizontal supports of ceilings or roof soffits.
2. On interior walls.

International Building Code 2510.5.2.2

Use of gypsum sheathing backing. Gypsum
sheathing is permitted as a backing for metal or wire fabric
lath and cement plaster on walls. A water-resistive
barrier shall be provided in accordance with Section
2510.6.

International Building Code 2510.5.3

Backing not required. Wire backing is not
required under expanded metal lath or paperbacked wire
fabric lath.

International Building Code 2510.6

Water-resistive barriers.Water-resistive barriers shall
be installed as required in Section 1404.2 and, where applied
over wood-based sheathing, shall include a water-resistive
vapor-permeable barrier with a performance at least equivalent
to two layers of Grade D paper.
Exception: Where the water-resistive barrier that is applied
over wood-based sheathing has a water resistance equal to
or greater than that of 60-minute Grade D paper and is separated
from the stucco by an intervening, substantially
nonwater-absorbing layer or drainage space.

International Building Code 2510.7

Preparation of masonry and concrete. Surfaces shall
be clean, free from efflorescence, sufficiently damp and rough
for proper bond. If the surface is insufficiently rough, approved
bonding agents or a portland cement dash bond coat mixed in
proportions of not more than two parts volume of sand to one
part volume of portland cement or plastic cement shall be
applied. The dash bond coat shall be left undisturbed and shall
be moist cured not less than 24 hours.