||Input Sought to Identify Exterior Fiber-Reinforced Cement Products
Suitable for Manufacture According to ASTM C 1325
Attendance is invited to a meeting of ASTM Committee C17 on Reinforced Cement Products, June 26-27, Norfolk, Va., to discuss
a major revision to an ASTM standard for fiber-reinforced cement
products. Input from manufacturers is needed to decide what exterior
product specifications will be added to C 1325 Standard Specification for Non-Asbestos Fiber-Mat Reinforced
Cement Interior Substrate Sheets.
The standard was originally published in 1996. Revisions to C
1325 are needed in order to establish test methods and specifications
for using the product as an exterior sheathing, said Keith A.
Poerschke, manager, Building Codes, Research Center, National
Gypsum Co., Buffalo, N.Y. The products currently manufactured
to this standard are frequently used for this. They function quite
well as an exterior sheathing, since it holds up very well when
exposed to moisture.
However, in order to write specifications for the product, several
of the manufacturers are going to have to come to some agreements
on what types of testing is needed. It may be that not all products
currently manufactured to C 1325 can, or will, function adequately
as an exterior sheathing. We expect concerns such as linear expansion,
water absorption, freeze/ thaw resistance, etc. will need to be
addressed to a greater degree than they are in the current standard.
As stated in the standard, C 1325 covers fiber-mat reinforced
cement substrate sheets manufactured to be dimensionally stable
and suitable as either an unfinished substrate or as a substrate
for decoration such as natural stone or tile in internal wet and
The referenced tile and natural stone are ceramic tile, and stone
cut into thin veneer to allow adhesive application to the cement
board similar to a tile installation, using latex modified Portland
cement mortars or other recommended adhesives, Poerschke said.
As a manufacturer, it is our hope that the use of these products as an exterior
sheathing will become more prevalent as a result of these changes
to the standard.
Architects, code officials, engineers, and contractors who reference
C 1325 are highly encouraged to attend the meeting, or provide
input to Keith A. Poerschke, manager, Building Codes, Research Center, National Gypsum Co.,
Buffalo, N.Y. (phone: 716/873-9750, ext. 234). Following the June
meeting, C17 next meets Dec. 4-5 in Dallas, Texas. For meeting
or membership details, contact Staff Manager Jim Olshefsky, ASTM (610/832-9714). //
Copyright 2001, ASTM