Many homeowners have the skills and capabilities to complete their
own home improvement projects and renovations. This can save immense
amounts of money as well as help home owners develop new skill sets they
can use in the future as new home improvements are needed. Large
projects such as home additions, new garages or adding a patio can also
be completed without hiring a professional. When building a new
structure, it is critical to securely fasten it to the foundation or
slab with the use of a sill plate.
A sill plate, also known as a sole plate, is the
bottom horizontal member of a wall or building to which the vertical
studs will be attached. Most sill plates are made from lumber - usually a
2x4, 2x6, 2x8 or 2x10. The sill plate is typically anchored to the
foundation or slab of concrete, depending on the application. Before
the next steps can take place, a sill plate must be anchored to the
foundation to ensure proper construction and safety.
Before You Get Started
Before trying to anchor a sill plate to any type of
foundation, it is important to determine which system is best for
attaching the sill plates.
One method for fastening sill plates is the use of
cast-in-place anchors, commonly referred to as "J" Bolts. "J" bolts are
anchors in the shape of the letter J with threads on the end opposite
of the bent end. These bolts are set in place before the concrete is
poured. The use of "J" bolts provides the best holding values, but can
be problematic for the do-it-yourselfer due to the expertise needed and
complicated installation steps. The "J" bolts must be installed
completely perpendicular and if not, numerous problems will occur when
trying to attach the sill plate. Also, this method cannot be used when
building a structure where there is an existing foundation, such as
replacing a dilapidated garage. This could pose a serious problem for
many home improvement projects.
28 days is the required time to fully cure concrete.
There is a type of concrete anchor that can be
used when working with sill plates in less complicated applications and
those with existing foundations. One option for installing sill plates
is the use of Wedge Anchors. This type of anchor is a
post-installed anchor, meaning that it is placed in concrete after it is
fully cured. These fasteners are designed for use in solid concrete only. Wedge anchors are available from 1/4" to 1 1/4" in diameter. The length of the wedge anchor
is completely dependent upon the thickness of the material to be
fastened. To determine the size of anchor needed, it is important to
check your local building codes or with an engineer or architect. It is
also critical to verify the holding values required for your particular
application since the quality of concrete will vary in every single
Choosing the Size Wedge Anchor to be used
Once the required holding values have been determined, use this wedge anchor sizing chart
to determine the appropriate diameter and length. There are some other
considerations when using wedge anchors. These include:
Step by Step Instructions
Concrete Wedge Anchors can be installed in a few steps. Basic instructions follow:
It is critical to remember that hole diameter is equal
to anchor diameter. This will affect the holding values of these wedge
- On the concrete, mark where your holes will be
drilled. Remember that anchors must be placed: a minimum of five
anchor diameters from any unsupported edge and there should be a minimum
of ten anchor diameters between any two anchors.
- Using a hammer drill, drill your holes using a carbide-tipped masonry bit. The hole diameter should be the same diameter as the wedge anchor.
- Clear the hole of all debris using compressed air, a shop-vac or wire brush.
- Before inserting the wedge anchor into the hole,
be sure to place the washer on the head and thread the nut a couple of
turns. By not fully threading the nut, the threads of the wedge anchor
- Carefully place the sill place in the correct position and insert the wedge anchors into each hole through the sill plate.
- Hammer anchors into every hole ensuring that they
are installed to the desired depth and securely in place. This will be
the supporting plate to which studs will be placed later in the
renovation process so secure placement is important for the overall
safety of the structure.
- Using a torque wrench, tighten every nut to guarantee they are tightened to the required torque value.
For more detailed information and further instruction, take a look at this Wedge Anchor Installation Video.
When using concrete wedge anchors, it is important to remember:
- Wedge anchors are very effective when the concrete is in good condition and minimum edge distances and spacing are maintained.
- Hole size is critical to the holding values of the wedge anchor. Hole diameter is equal to the anchor diameter when using ANSI standard carbide bits. The tolerances of ANSI standard bits are specifically matched to work well with wedge anchors.
- Wedge anchors have a required torque value. Take a look at this important anchor technical information page to determine the diameter of anchor to use for a range of required torque values.
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.