Assembly Instructions

© 12/14 Allura, Printed in U.S.A.
www.AlluraUSA.com
Allura USA | 15055 Woodham Drive | Houston, Texas 77073 | 1 844 4 ALLURA (1-844-425-5872)
© 12/14 Allura, Printed in U.S.A.
Installing caulking at ber cement siding
bu joints/edges during installaon
Bu end/joints should be installed with factory-sealed
or factory-prenished ends bued together in moderate
contact. 2006 Internaonal Building Code: 1405.17.2
Horizontal Lap Siding states the following regarding applying
caulk at the bu end/joint of horizontal lap siding:
Lap siding shall be lapped a minimum of 11/4 inches
(32 mm) and shall have the ends sealed with caulking,
covered with an H-secon joint cover or located over a
strip of ashing. Lap siding courses shall be permied to
be installed with the fastener heads exposed or concealed,
according to approved manufacturers’ instrucons.
The goal of the methods outlined both by Allura and
the Internaonal Building Code for installing the bu
end/joint of ber cement siding is to manage the ow
of water at these areas. Requiring the installer to “back
ash” the bu the end/joint of two panels in moderate
contact increases the aesthec appearance of the nished
bu end/joint while eliminang any requirements for
future maintenance of the caulking at the bu end/
joint. Applying caulk to the bu joint can be ineecve
due to the gap not being large enough to accommodate
the sealant, and on prenished products it may leave an
unsightly looking nish. Spreading or feathering the sealant
into a thin lm will create a noceably dierent appearance,
and can also remove the needed thickness required to
withstand UV exposure and joint movement. In place of
caulk Allura recommends (but does not require) the use of
a bu end/joint ashing made of a durable, non-corrosive
material that is compable with ber cement siding (e.g.
15 lb felt, trim coil, joint ashing, etc). Addionally, many
sealant manufacturers have changed their installaon
instrucons to disallow gapping the siding and applying
caulk at the bu end/joint during installaon (although
some sealant manufacturers do sll allow for back-buering
(Caulk) the edges of the panel at the bu end/joint).
NOTE: Refer to your sealant manufacturer’s specicaons
to determine if they allow the caulking of ber cement
siding bu joints/edges, what their minimum and maximum
gap requirements are and/or how this pracce may aect
the warranty for the caulking.
If the architect, designer, installer, project manager,
contractor, property owner, code ocial or other enty
involved with determining the method of installaon on a
project determines that spacing the bu joints and applying
caulk is an acceptable pracce during installaon, such
pracce will not aect the eligibility of the Allura Fiber
Cement Siding product installed on the project for warranty
coverage with regards to product defect, provided that the
caulking of the bu joints does not inict, cause, or otherwise
create a condion where this pracce was, is or becomes the
cause of product failure.
(Connued on reverse side)
TECHNICAL BULLETIN
Applying Caulking at Allura Fiber
Cement Siding Bu Joints