to Build a Deck
Brushes, rollers (for finish)
Drills and bits
Hoe and hose (to mix concrete)
Post hole digger
Shims or spacers
Stakes or batter boards
Two foot level
Decks originally became popular as a way of adding outdoor living space on hillside lots. Today,
many decks are built on level ground where they offer firm, dry footing close to the home. Decks add to
the living area of your home and increase its value. Recent studies have shown that in most cases over
200% of the investment can be recouped on decks built by do-it-yourselfers when they sell their house.
Decks can be built just inches from the ground or well elevated. They may be freestanding or attached to
the home or other building. Before you begin actual deck construction you need to take into account
some basic considerations.
Building Code and Zoning Requirements
Many areas require building permits, and your plan may need to be reviewed
by your local building code office to make sure that it meets the standards
set forth in local codes. Make sure you will be building with any setbacks
specified in local regulations. Some communities have rigorous design guidelines
and require review committee approval of alterations to the exterior of properties.
Contact your local utilities to be sure that your proposed deck won't interfere
with access to utility lines. Finally, don't interfere with the functioning
or servicing of your septic tank if you have one.
How you plan to use your deck will determine the size deck you need. For
family meals and entertaining, select a large deck (or combination of decks)
with plenty of space for tables and benches, and consider adding built-in
benches along the railings to seat more people. An entry deck can be small,
but make it large enough for you to be able to stand and talk comfortably
with guests as they arrive or leave.
Sun and wind are the important things to consider. Depending on where you
live, afternoon sun can be a welcome friend or a hot, fierce enemy, so plan
carefully. Think also about which areas of your yard have pleasant, gentle
breezes, or those that always seem too cold or windy. Whatever your local
conditions, plan your deck to give you the sun or shade you want with protection
from high winds.
Every situation is unique, but the following considerations are common.
Take advantage of good views, both on and off your property and screen off
unpleasant ones. Think about how your intended deck use and intended deck
placement can work together. An outdoor eating-and-entertaining deck should
be close to or easily reached from your kitchen and living area. A deck intended
for adult privacy might be better placed away from busy household activities.
Considered together, all these factors may point to an excellent location
for you to build your deck, but usually you will have to think about compromises
and modifications. For instance, if all other things are perfect about the
location for your deck, but you think you'll want more shade, consider adding
an overhead arbor or a lattice screen. Is the only problem inadequate protection
from high winds? Then add a taller, solid railing along one or two sides.
Or does an otherwise great location feel too shady and damp? Perhaps thinning
some overhead tree limbs (or even removing a tree) can get more sunlight on
Basic Rectangular Deck Framing
When most people think of decks, the one that comes to mind is rectangular,
elevated on posts, with railing and stairs. The basic framing plan shown for
a rectangular deck has some dimensions that are fixed (such as the spacing
between joists and the amount of overhang for the ends of joists where they
extend past the beams), and others that are described simply as "maximum"
(overall length and width of deck, beam and joist spans, height of deck posts,
etc.) (See Figure 1).
Step 1: Install Ledger
Install a ledger to anchor the deck to the house and to serve as a reference
for laying out footings (Figures 2 and 3). The placement of the ledger
determines the level of the deck floor. It is important that it is positioned
at the correct height and is horizontal. If you are unsure of how to do this
crucial step, consulting a professional contractor is recommended, or design
your deck to be free-standing. This will eliminate the need for a ledger board.
Use batterboards and mason's strings to mark off the deck area and locate
footings. The strings will help you visualize the size and appearance of the
finished deck. (Figure 3)
Square with string
Attach the string to the ledger and/or batterboards making sure it is level.
The batterboards should be assembled just outside of the perimeter corners
of the deck as illustrated below. Batterboards will be used to hold and adjust
strings which define the deck area and height. Use a felt tip marker to mark
the string 3' from the corner and mark 4' from the corner in the other direction.
Adjust the string until the diagonal connecting these two points is 5'. This
will result in a 90-degree angle in the corner. This is commonly referred
to as the 3-4-5 method. (Figure 4)
Step 2: Prepare the Site
Decks usually shade the soil sufficiently to prevent most weed growth, but
getting weeds out of the way before you begin to build makes construction
easier. After measuring and marking the deck area, remove sod from the staked
area to a depth of 4" to 6". Replace the soil with gravel and level
Step 3: Install Posts
Using a line level, measure in from the batter board strings the distances
given in the plan for the location of the posts. The depth of post holes are
determined by local code, however, the post holes should be at least 24"
deep and can be up to 4' deep. The actual depth depends on the height of the
column and the depth of the frost line in your area, Figure 5. Posts need
to be set deeper than the frost line to avoid heaving. Check with your municipality
for local requirements for depth and width of post holes. Fill the bottom
of the hole with gravel and place a treated wood block on the gravel. Set
the posts in the holes, check for level and brace securely. Fill the hole
with concrete or alternating layers of gravel and earth. Make sure the posts
are plumb and in alignment with one another. Let posts set in concrete overnight
Setting posts in-ground is the method recommended, but there are several
options available. If you have rocky soil or a deep frost line, you may want
to use one of the several types of pier blocks illustrated here. You do not
have to dig holes when using pier blocks, and, depending on the type you choose,
the posts can be attached in a variety of ways (Figure 6).
Post height is determined by measuring from the top of the deck to the ground
plus the length of post set in the ground minus the thickness of the decking
and the width of the joists. Height of posts that extend above the decking
to support railings or benches is determined by adding the length of the post
underground plus the distances from ground level to deck level plus the height
of the railing, bench or features minus the width of the railing cap, seating
boards or other materials.
Do not cut posts to their finished length yet. Allow extra length to accommodate
Perimeter posts over 5' high from ground to deck level need to be braced.
While there are several methods of bracing, "X"-bracing is the strongest
and is the method we recommend. In X-bracing, 2x4 or 2x6 boards run diagonally
from just below the beams on one post to approximately one foot above ground
level on the neighboring post. If the diagonal distance is less than 8', use
2x4s; if 8' or greater, use 2x6s. (Figure 7).
On corner posts, run the brace to the outside corner of the post, secure
with 3/8"x4" lag screws or 3/8"x5 1/2' carriage bolts. Trim
the end flush with the post. Braces that meet at middle posts are cut to meet
at the center line of the posts (leaving a slight gap for drainage), and attached
with lag screws or carriage bolts. Where braces cross between posts, fasten
them with a single 3/8" x 3 1/2" carriage bolt.
Note: Post heights over 10' (ground to deck level) may require the services
of a professional landscape architect or civil engineer.
Step 4: Attach Beams to Posts
Use a string and level to find the desired deck floor height on the posts.
Subtract the thickness of the deck boards and joist (use actual dimensions
not nominals) to determine the correct height for securing the top of he beam
to the post. Make a mark on all four sides of the post at this point. Use
carriage bolts to fasten the beams flush with the mark. You can cut the posts
that do not serve as railing supports before attaching the beams. (Figure
Step 5: Attach Joists
It is important that the surface of the deck have a rock-hard feel, especially
elevated decks. To achieve this joists should be spaced a maximum of 24"
on center. For decks over 6 feet off the ground, the maximum joist spacing
should be 16" on center. Joists are attached to the ledger with joist
hangers or by toenailing. They must also be attached to the beams and ribbon
joists (Figures 9,10).
Blocking consists of 2x6 pieces nailed between joists to prevent buckling
or twisting. Measure and cut blocking and nail through joists into ends of
the block pieces. For ease of nailing, snap a chalk line across the joists
where the blocking will go and stagger the pieces to the left and right of
the line (Figure 11).
Step 6: Lay decking
Decking will be one of your deck's most visible features, so make every effort
to lay decking boards straight and in line. Butt boards together because as
drying occurs some shrinking can be expected. Also, when appearance permits,
attach boards "bark side up" to help minimize cupping and warping.
Attach the decking boards to each joist with a pair of 2½" galvanized
If you use straight planing for decking, you can trim the deck boards after
they are installed to assure a straight line. Snap a chalk line flush with
or up to 1 1/2" out from the ribbon joist and trim with circular saw.
For a more finished appearance, cut boards flush with the joist and add a
In addition to laying straight planking, you can choose from a variety of
different patterns for attaching decking (Figure 12). Diagonal or herringbone
designs all add visual interest to the surface of your deck. These attractive
patterns usually require slightly more material than straight planking. More
cutting and attention to precision is required. (Note: the Deck Designer only
allows for straight and angled planking).
Railings enhance the safety and appearance of decks and are required above
certain deck heights. Check local codes. Railings must be sturdy and should
be firmly attached to the framing members of the deck. They can be plain or
elaborate and offer great opportunities for individual preference. Decorative
ball tops and turned spindles as well as a variety of other specialty products
are available to enhance railings (Figure 13).
Support for the railings can come from the continuation of deck posts that
extend up through the deck floor or railing posts that are bolted to the outside
joists or joist extensions. A common rail height is 42", but check for
any special code requirements for your area. If you decide to use the deck
posts, you may need to add intermittent or spacer posts for additional support.
Never span more than 8 feet between railing posts. Check for any local code
If you chose to attach posts to the outside joists or joist extensions, you
must attach each post to the rim joist with at least two 3/8"x5"
carriage bolts. For a finished look, you may want to bevel cut the end of
the 4x4 post below the screw heads. Decorative handrail posts, spindles and
handrail designs are available to dress up your deck.
Once the railing posts are cut to their proper height, you can install the
cap rail and other horizontal rail members. Miter cap rails where they meet
at right angles over a post. Galvanized screws should be used to attach the
Probably no aspect of deck construction requires more care and thought than
stair building, largely because there are so many variables that can change
from deck to deck. The options shown here will help you get started. The following
discussion is intended to help you plan and build a safe and attractive stairway
customized to your particular requirements.
Decide how wide the stairs will be. They should be at least three feet wide,
but often look and work better if they are wider. Check local codes to determine
the maximum width allowed for stairs. You may need to add additional handrails
on wide steps. For 2x4 or 2x6 treads laid flat, you will need 2x10 stringers
at least every 42". Middle stringers must be cut; those on either side
may be cleated or cut (Fig. 14).
For ease of construction, plan on 7" risers and approximately 11"
treads, which can be made from 2x6s or three 2x4s.
Measure total rise to determine number of steps needed. Make the first step
up from the ground 4" to 10" as needed to have all other risers
be 7". Based on the number of 11" treads needed for the number of
risers calculated, determine where steps will meet the grade - total run.
Mark this point with a stake.
Both cut and cleated stringers must be cut to fit the deck and ground. Measure
the diagonal distance from the top edge of the deck to the total run stake.
Purchase 2x10 stringers that are somewhat longer than this distance so that
they can be trimmed to finished shape when the tread-riser relationships have
been worked out (Figure 14).
Measuring Treads and Risers
Mark the 7" riser and 11" tread distances on the two arms of a
carpenter's square. Place the square so that it intersects the stringer edge
at the two marked points. Mark stringer and continue for the total number
of treads and risers needed.
For cut stringers, use a circular saw to cut the stringer to final shape.
For cleated stringers, attach 2x4 cleats so that the tops are 1 1/2"
below the marked tread locations to allow for width of the tread boards.
Cleated stringers can be toenailed to the box frame or bolted to posts added
for railings. Cut stringers must be nailed or bolted to the existing box frame.
In either case, the top of the cut or the top of the first cleat down must
be 8½" below deck surface. Once the 2x treads are attached to the
top step, you will have your 7" riser.
Stringers need support where they meet the ground. An easy support can be
made with a 4x4 leveled in compacted earth or gravel; toenail the bottoms
of the stringers to the ingrade 4x4. A small concrete pad can also serve as
a suitable support.
Cut 2x4s or 2x6s to length, space as you would decking, and nail boards to
cut stringers or cleats.
Add in-ground posts and intermediate posts bolted to stringers, as needed,
to continue deck railing down the steps.
They may look, at first glance, to be complicated, but multi-level decks
are really no more difficult to build than simple rectangular decks. In fact,
a sophisticated multi-level deck can be nothing more than two rectangular
decks joined together visually. Plan and build a multi-level deck with the
following points in mind.
Generally, multi-level decks look best when one rectangle is clearly larger
than the other. By all means, adjust the size of the rectangles to fit your
own needs (Figure 15).
The simplest way to change levels is to build the second deck 7" higher
or lower than the first. If you need a greater difference, handle the change
with stairs, connecting deck to deck, as you would deck to ground.
One simple modification to square or rectangular decks is angling one or
more corners. Angling the corner will require extra posts and additional beam
assemblies running diagonal to the 45-degree angle on the corner. The framing
plan to the right shows where the extra posts and beam assemblies should be
added. Angling all four corners will result in a hexagonal deck that is usually
freestanding in the landscape (Figure 17).
Accessorizing your Deck
These are many ways to give your deck a custom look. Here are some ideas
for a bench and lattice screen.
Benches add seating to a deck without taking up much floor space. They also
help customize the deck.
Using pressure treated lattice (or aprons) around the perimeter of your deck
really adds eye appeal. Lattice will cover the posts and framing and is a
simple way to customize the appearance of your deck. Lattice is available
in different sizes, and you may want to consider using special framing which
is also available to hold the lattice in place.
You will spend a lot of time and money on your deck and other outdoor projects.
The lumber used around your home needs care and maintenance to help protect
your project from the harsh effects of weathering caused by rain, sunlight
and temperature change.
A high-quality wood preservative protects wood from fungal decay and termite
attack. However, only a regular maintenance program can help minimize the
effects of the weather on your outdoor project. Whenever a project is built
with wood and exposed to the weather, certain inherent properties of wood
"Weathering" of wood is sometimes confused with fungal decay, but
weathering is not fungal decay.
Here are some examples of what can happen to wood due to its natural properties:
Checks, Splitting and Grain Raising
These diagrams depict a cross section of wood, which displays some of the
natural behavioral tendencies of wood. As wood is exposed to alternative cycles
of wetting and drying, some checking and splitting may be expected.
Bowing, Crooking, Cupping and Twisting
These diagrams show some of the other ways in which wood reacts to weather
exposure. Wood may bow, crook, cup or twist in varying degrees depending on
stresses released by initial sawing of the lumber and moisture absorption.
Warping and Splitting
These diagrams depict a cross section of wood which displays severe warping
and splitting. Severely warped or buckled wood is wood which has twisted to
the point where it is an eyesore or structurally unsound. Severely split wood
will have a crack that goes completely through the board and has opened. These
severe warping and splitting conditions can sometimes be corrected, but in
cases where the lumber cannot be salvaged, it should be replaced with new
Regular Inspection and Replacement
Severely weathered lumber that cannot be salvaged should be replaced with
new lumber. It is unfortunate, but in spite of a homeowner's best efforts,
including the application of weather resistant finishes from time to time,
some pieces of wood due to the natural growing characteristics in the grain
pattern will mechanically degrade as a result of weathering over time to become
unuseful and unsightly. A homeowner's regular maintenance program should include
periodic application of compatible weather resistant finishes and inspection
of all fasteners to determine if nails, screws or bolts are working themselves
loose. A nail which has popped out of the wood can be driven back or replaced
with a screw and splitting boards can, in some cases, be reinforce with additional
Reprinted with permission, Osmose Inc.