When placing a door in an opening, these doors must be fastened to
the base material that is present in this location. Most frequently,
this base material will be concrete, brick or block and will require the
use of special concrete fasteners. Door frames may
range from solid wood to hollow steel. Because of this wide range of
possible materials, unique concrete fasteners may be required. These
anchors may require features that are not commonly found in concrete
fasteners. Often the thickness of the material to be fastened is larger
than normal. Such is the case when using a hollow steel door frame. This
application will require a longer than normal fastener to be used. Door
frames may also require the use of a countersunk head anchor since the
head of any fastener in a doorframe must not protrude into the opening.
The two requirements described- longer than normal length and flat
countersunk head- create a limited choice of effective concrete anchors
for this application.
Hollow Metal Door Frames
Standard metal doors are 1-3/4" thick, are manufactured from 16,
18 and 20-gauge steel and are galvannealed. Galvannealed steel is a
process in which an extra tight coat of metal zinc is applied to a soft
steel sheet and then passed through an oven at about 1200°F. This
process creates a dull gray coating that is well-suited for painting.
Wood Frames
Wood door frames come in many different thicknesses and wood
types. The exact specifications of the particular door frame being
mounted will determine the length of the concrete fastener needed. It is
important to remember that a flat countersunk head anchor must be used
and sit flush with the outside surface of the door frame.
Concrete Fasteners That Can Be Used in Concrete, Brick or Block
Once the style and type of door has been chosen, the base
material of the opening in which the door will be placed must be
determined. The base material will determine the type of fasteners that
can used in that particular application. Most concrete fasteners are not
available in a flat head countersunk head, this means that the
selection for the correct ancor will be smaller than with most other
applications. The sleeve anchor and Tapcon® concrete screw come standard
with a flat head phillips countersunk head and are readily available. A
female type anchor with a flat countersunk head can be used but are not
recommended for this application because they are difficult to work
with. Therefore, this article will not explore the use of this type of
anchor.
Sleeve Anchors for Attaching Door Frames
Sleeve anchors
are very versatile concrete fasteners because they come in a wide range
of lengths, head styles and diameters. Sleeve anchors are designed to
be used in a variety of base materials including concrete, brick and
block. These anchors are available in four head styles: acorn, hex,
round and flat head. A flat head sleeve anchor would work perfectly for
fastening metal door frames to base materials. Sleeve anchors are
manufactured for the hole size and the countersunk head type are
designed into the door frame. The length of the anchor to be used will
be determined by the thickness of the metal door frame plus the minimum
embedment for a 3/8" sleeve anchor- which is 1-1/2".
The 1st table below displays the holding values in concrete and
the 2nd table describes the holding values in grout filled block.
** Note that the holding values are based on 1-1/2" embedment
into the concrete and are ultimate loads. To calculate a safe working
load, divide the ultimate load by 4.
Sleeve Anchor Ultimate Holding Values - Concrete
| 3/8” x 4” |
Flat |
3/8” |
1580 |
2400 |
| 3/8” x 5 |
Flat |
3/8” |
1580 |
2400 |
| 3/8” x 6” |
Flat |
3/8” |
1580 |
2400 |
Sleeve Anchor Ultimate Holding Values - Grout Filled Block
| 3/8” x 4” |
Flat |
3/8” |
1150 |
2400 |
| 3/8” x 5 |
Flat |
3/8” |
1150 |
2400 |
| 3/8” x 6” |
Flat |
3/8” |
1150 |
2400 |
Tapcon® Concrete Screws for Attaching Door Frames
The only diameter of Tapcon®
that comes in a 4", 5" or 6" length is the 1/4" diameter concrete
screw. This is a smaller diameter than the sleeve anchor but is used by
many door installers for this application. The flat countersunk head is
large and fits nicely into the hole with a countersink manufacture into
the metal door frame. Tapcons are perfect for wood frame doors because
they are easy to use and make their own countersink in the wood as the
screw is torqued into the base material. It is important to note that
these concrete screws are threaded for a length of 1-3/4" from the point
of the screw. This is because they require a depth of embedment into
the base material of no more than 1-3/4" and a minimum embedment of 1".
The 1st table below describes the holidng values of Tapcons in
concrete. The 2nd chart contains the holding values of concrete screws
in block.
** Note that these are ultimate loads and must be divided by 4 in order to obtain the safe working load.
Tapcon® Ultimate Holding Values - Concrete @ 1-3/4" Embedment
| 1/4” x 4” |
Flat |
3/16” |
2020 |
1670 |
| 1/4” x 5” |
Flat |
3/16” |
2020 |
1670 |
| 1/4” x 5” |
Flat |
3/16” |
2020 |
1670 |
Tapcon® Anchor Ultimate Holding Values - Block @ 1-3/4" Embedment
| 1/4” x 4” |
Flat |
3/16” |
250 |
620 |
| 1/4” x 5” |
Flat |
3/16” |
250 |
620 |
| 1/4” x 5” |
Flat |
3/16” |
250 |
620 |
Both the sleeve anchor and Tapcon® allow door frames to be placed
in position, leveled and plumbed before the anchor is inserted through
the door frame. There is no prior spotting of the hole. Simply drill the
hole in the base material with the door frame in place, insert the
concrete anchor and tighten.
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.