Brick anchors are fasteners that attach an item to brick or a mortar
joint in a brick wall. Brick anchors are different from concrete
fasteners because the base material of brick is most commonly found to
have hollow space, unlike concrete that is solid. The hollow space
requires the brick anchor to be versatile enough to obtain holding
values in the hollow areas of the brick.
Male Expansion Brick Anchors
The sleeve anchor
is the most commonly used male expansion brick anchor and it provides
the most consistent holding values. The design of the sleeve anchor
allows for the anchor to expand over a greater surface than any other
expansion type anchor. This gives the sleeve anchors the ability to
expand properly in the hollow sections or solid sections of brick. The
sleeve anchor can also be used in the solid mortar joints. It is
important to remember that the ultimate holding value of the sleeve
anchor is dependent upon the quality and quantity of mortar. The
versatility of the sleeve anchor’s range of applications comes with only
one drawback, which is that it has less shear strength than the same
size female type anchor. The sleeve anchor’s designated size is equal
to the outside diameter and the stud is smaller. For example, a 3/8”
sleeve anchor has a 5/16” stud, thus giving the sleeve anchor the shear
strength of a 5/16” anchor and not of a true 3/8” diameter.
Available diameters- The sleeve anchor comes in six
diameters and in a number of different lengths for each diameter
depending on the application. The minimum length of sleeve anchor to be
used is determined by adding the thickness of the material being
fastened to the minimum embedment of the diameter of sleeve anchor being
used.
Available head styles- Sleeve anchors are available with
a number of different head styles: acorn head, hex head, round head and
flat head. The acorn head is hex with a finished acorn head; the hex
head is the standard hex nut; the round head is slotted for use with a
straight screwdriver; the flat head is countersunk phillips or slotted
drive. The head style to use is determined by the particular
application in which the sleeve anchor will be used.
Sleeve Anchor Lengths-The length of the sleeve anchor is
measured from under the head for the acorn, hex headed and round sleeve
anchor. The flat-headed sleeve anchor is measured as an overall length.
Self Tapping Brick Anchors
Self-tapping brick anchors are most commonly called Tapcon® masonry screws
are used for fastening to brick. The masonry screw is versatile
because it can be used in brick, mortar joints, CMU, block or solid
concrete. The masonry screw is used in brick by first drilling a hole
with a hammer drill with the correct diameter carbide bit for the
masonry screw being installed. The masonry screw is then inserted into
the hole in the brick and turned clockwise, tapping threads into the
brick and holding the screw securely.
Masonry Brick Screw Sizes- The standard masonry brick
screw comes in two diameters of 3/16” and 1/4” with lengths ranging from
1-1/4” to 6”. The minimum length of masonry brick screw to use is
determined by adding the minimum embedment depth of 1” to the thickness
of the material being fastened.
Head Styles- Two head styles are available with the
standard masonry brick screw: the hex washer slotted and the flat
countersunk phillips. All the hex washer slotted masonry brick screws
lengths are measured from under the head and the flat countersunk
phillips is measured as an overall length.
Female Expansion Brick Anchors
A number of different types of female brick anchors are
available. The best one to use depends on personal preference and the
specific application. Each female anchor requires a bolt and washers to
be purchased separately. Many times the bolt chosen will determine the
female anchor that will be used. If a lag screw is used then the lag
shield brick anchor will be used. If a bolt is used with national
coarse threads then any of the female brick anchors with internal
national coarse threads can be used. Some of the female brick anchors
require a setting tool to be used to set the brick anchor into the base
material. These types of brick anchors require that the anchor be
placed so that setting tool can be used to set the anchor into the brick
properly.
Types of Female Brick Anchors
Machine Screw Anchors
– Often called AJ’s or lead anchors, they require a setting tool that
has national coarse threads. They are available in eight diameters and
can be used in brick, block or concrete.
Lag Shield Anchors
– These anchors are available in two different lengthsof a short or
long version and six diameters. The lag shield is very versatile
because it can be used in very dense base material or in base material
where the holding values are suspect. The lag shield does not require a
setting tool and is expanded by inserting the correct lag screw into
the anchor.
Double Expansion and Single Expansion Anchors
- These anchors both come in five diameters, have national coarse
internal threads and have good holding values in most base materials.
The double expansion expands the entire length of the anchor body as
opposed to the single expansion that expands at one end. The double
expansion anchor is primarily used over the single expansion anchor in
applications where the base material may be soft, suspect or
inconsistent.
As with any anchoring project, it is important to keep safety in mind and follow instructions carefully. Always remember to wear safety goggles, handle all tools with extra care and follow all technical specifications. This article is meant to serve only as a basic explanation of concrete fasteners. Always refer to manufacturer's instructions or consult a contracting expert during any anchoring project.
Article Written By:
Bob Carlisle, President of Concrete Fasteners
Concrete Fasteners, Inc. has over 40 years of experience selling concrete fasteners. We can ship out one box or a whole pallet of concrete anchors. Our products are of the highest quality... "your satisfaction is guaranteed". We ship all orders the same day the order is received.