Deck Construction
Planning A Deck The Secret of Redwood s
Redwood is a wood like no other and
The first step in building a deck is to sur- Long-Lasting Beauty
decks built of redwood are unique in their
vey your yard and decide what problems Redwood decks look better than decks
beauty and long-lasting service. There s
the deck can solve. made of other woods and keep their
a grade of redwood lumber for any part
handsome appearance longer because
of any deck luxury decks, economical
Do you want to level a sloping yard?
redwood is naturally stable. This means
decks, simple decks and decks that push
Create a central activity area? Upgrade a
redwood deckboards nail down flat and
the limits of definition.
side yard? Minimize landscape mainte-
stay in place resisting warping, cupping,
nance? Make a barbecue or picnic area?
Deck building isn t difficult. In fact, it s a
splitting and checking.
perfect project for learning basic con- Whatever problems you solve, you ll find
struction skills.Your deck can be as sim- your deck is a clean, dry place to enjoy You ll find that redwood lumber has two
one of the best sides of your home predominant colors: cinnamon-red and
ple or complex as you wish to make it.
the outside. creamy yellow. The cinnamon-red wood
The care taken in planning, choosing
is heartwood and comes from the center
materials, double-checking measure-
In selecting a site for a deck, it is important
of the tree. The creamy yellow wood is
ments and adding personal finishing
to think about privacy, safety, access to
sapwood and comes from the portion of
touches will go a long way in making
the house and protection from wind,
the tree near the bark. Some redwood
your deck project look professional.
noise and weather. Landscaping features
grades are all heartwood while others
must also be considered.
This booklet contains deck construction
permit both heartwood and sapwood.
techniques and specifications based on
Think about the seasons when the deck
decades of cumulative deck-building
will be used and the sun s path during the
experience. It does not provide plans for
year. Often a southwestern or southeast-
building a specific deck, but it has valu-
ern exposure is a good choice to take ad-
able information that will help with any
vantage of the morning or afternoon sun.
deck project.
Don t forget to locate underground utility
lines! In some cases, it may be wise to
reposition the deck slightly to avoid inter-
fering with utilities. In all cases, it is
important to be aware of their placement.
Garden Grades Grains Sizes of Garden Grade Lumber
Garden grades of redwood are tailor- Lumber has either flat or vertical grain Surfacing and seasoning reduce the
made for decks and they are not expensive! depending on how it was cut from the dimensions of lumber. As a result, the
They have knots which give them a rustic log. Garden grades are sold with mixed actual dimensions of all lumber are
look that blends well with landscaping and grain patterns. To minimize cupping and different from the nominal dimensions.
other natural materials. Redwood garden grain raising, flat grain lumber should The chart below lists the actual and
grades are available in dimensions from be used with the  bark side up or nominal dimensions of redwood garden
heavy timbers 20 feet in length to light- facing out. Vertical grain lumber provides grades.
weight benderboard often used for edging the smoothest surfaces for railings
garden walkways. Grades that have the and benches.
S4S Dry Sizes (Inches)
word  heart in the name are entirely
Thickness Width
decay-resistant heartwood.
Nominal Actual Nominal Actual
Vertical Grain Flat Grain
11
1 D 16 2 11D 2
Construction Heart/Deck Heart
11D 4 14 31D 2
All-heartwood grade containing knots; rec-
ommended for work on or near the 2 11D 2 6 51D 2
ground and for posts, beams, joists and
8 71D 4
deckboards. Deck Heart is graded for
10 91D 4
Annual Rings Bark Side Pith Side
strength characteristics and is available in
S4S Green Sizes (Inches)
2x4 and 2x6 only.
Thickness and Width
Seasoning
Construction Common/Deck Common
Nominal Actual
Seasoned or unseasoned garden grade
Similar to Construction Heart and Deck
lumber is suitable and most economical
4 39D 16
Heart except containing sapwood;
for decks and other outdoor projects.
6 51D 2
recommended for most above-ground
Architectural grades marked  Certified
8 71D 2
applications such as railings, fences,
Kiln Dried are pre-shrunk and have
10 91D 2
deckboards and trellises. Deck Common
superior stability. They are good for areas
is graded for strength characteristics and
requiring tight joints, such as outdoor
is available in 2x4 and 2x6 only.
shelves, cabinets and detail work. Specifying Redwood
Merchantable Heart Most economical When you order or specify redwood
Textures
all-heartwood grade, allowing larger knots lumber, it is important to list the following:
Redwood is generally available with a
and some knotholes; used for retaining intended use, grade, seasoning, size
smooth, planed surface on all four sides,
walls and garden or utility structures on or and texture.
known as S4S. Larger dimension timbers
near the ground.
For Example: Redwood lumber for
(4x4 and greater) are often available
Merchantable Same characteristics as (use) decking shall bear the Redwood
rough. Surfaced lumber is best for
Merchantable Heart but containing sap- Inspection Service grademark and shall
sitting and walking surfaces or areas
wood; suitable for fenceboards, trellises be (grade) Construction Common,
to be painted.
and above-ground utility applications. (seasoning) unseasoned, (size) 2x6,
(texture) S4S.
Architectural Grades
Architectural grades of redwood are vir-
tually knot-free or in the case of B Grade,
contain knots of limited number and size.
Redwood
Architectural grades are the top of the
Grades
redwood line. These grades are usually
and Uses
kiln dried to pre-shrink the lumber, but
they are also available unseasoned. Often
used for quality siding and interior panel-
Architectural            
ing, architectural grades can be used for
highly-visible landscape architecture Garden            
where maximum stability is necessary.
Knots
     
Clear All Heart All-heartwood, free of
Sapwood      
     
knots; recommended for highly-visible
applications like deckboards, railings,
Posts         
     
overhead shade structures.
Beams         
     
Clear Similar quality to Clear All Heart
Joists         
     
except containing sapwood; uses include
railings, fences, deckboards, benches      
Decking
and trellises.
Rails      
Heart B All heartwood grade containing
Fenceboards
limited knots and other characteristics not
Benches
permitted in clear grades; uses same as
Clear All Heart.
Planters            
B Grade Similar quality to Heart B
Trellises
except containing sapwood; uses same
Furniture
as Clear.
Suitable grade for use
Most economical grade for use
t
k
le
le
k Hear
t
t
hantab
c
hantab
t/Dec
t
c
Construction
Clear
Construction
Mer
Common/Dec
All Hear
Hear
Hear
Mer
B Hear
B Grade
Common
Clear
Laying Out the Deck
With the preliminary planning done and
Mark the area for your deck with stakes
the business of redwood grade, sizes,
and string. Consider all the points men-
seasoning and textures taken care of, you House
tioned under  Planning on the first page.
can start thinking about the actual
structure of the deck. Decks are walking
The deck perimeter can be laid out and
surfaces held up off the ground by an
squared in any number of ways. For Second Measurement
understructure. The deck must be strong
example, if the deck is to extend from the
enough to support the weight of people,
corner of a house, it is easy to project a
planters, benches, snow or anything else
string line from the non-deck side of the
that might be placed on the deck. The
house. This line and the wall where the
understructure of a deck can have some
deck will join the house form two sides of
or all of the following members: footings,
the deck perimeter. Next, measure the
posts, beams, joists.
length of the deck from the corner along
the wall of the house. With the third corner
The footings sit on or are partially buried
marked, the location of the last corner
in the ground. Posts are vertical members
can be determined by measuring from
that rest on the footings and support the
Projecting Lines From the Corner of
these other established points.
beams. Beams support joists, which are
a House.
usually spaced about two feet apart and
The accuracy of any rectangle can be
support the decking. The decking is the
proven by diagonal measurements
surface of the deck.
between the farthest corners. When the
diagonals are equal, the rectangle is true.
Each member of the deck is important
In some cases, the house or structure a
in carrying the load and distributing
deck is attached to will be out of line. It is
the weight evenly. Proper spans the
usually best to make the deck conform to
distance between two supporting
the structure.
members make for a safe deck and
one that feels solid when you walk on it.
Another method for determining the accu-
racy of a right angle is to create a right-
The following pages contain detailed
angled triangle with sides 6 feet by 8 feet
descriptions of each part of a deck and
by 10 feet (or proportionate measure-
techniques for putting them together.
ments). Using string, run two lines from a
proposed 90 degree corner. Measure and
mark points 6 feet from the corner in one
If A = B Corners Are Square (90°)
direction and 8 feet in the other. A line
connecting these two points and complet-
ing the triangle should be 10 feet in
length. If it isn t, adjust the perimeter lines
to square the corner.
Once the perimeter is staked out, it is
time to place the footings.
6'
8'
Checking an Angle Using a Right-Angled
Triangle.
First Measurement
Third Measurement
B
A
10'
Footings Posts
Beams can rest on top of posts or double
Deck footings rest on the ground and sup- Posts are vertical members which rest on
beams can straddle the post. The double
port the deck posts. Footings may be the footings and support the beams. The
beam method uses two pieces of thinner
either concrete blocks, pre-cast pier length of the posts is critical in establish-
dimension lumber. Sometimes this can
blocks or poured concrete pads. As a rule ing the height of the deck. Plan ahead
mean a savings. Naturally, if the double
of thumb, a footing should be about twice extended posts serve as a support for
beam method is used, the posts need to
the size of the post it supports. For exam- railings, benches and overhead trellises.
be taller.
ple, 4x4 posts should rest on 8x8 con-
Timbers 4x4 and larger are most often
If a single beam is going to rest on top of
crete footings.
used for posts. If large crowds, deep
the post, the post top must be trimmed
Building codes are usually specific about snow or other heavy loads are expected,
carefully to make a solid seat for the
the form and placement of footings. In or if the deck is elevated, larger posts
beam. Double-check measurements
general, they are required to extend may be needed and cross bracing may
before sawing. Measure and level the
below the frost line and they should be necessary to prevent lateral move-
post from a stable reference position.
extend above the ground to keep wood ment. Local building codes will answer
Make sure the posts are plumb when they
posts away from ground moisture. these questions.
are measured, installed and trimmed.
Mixing and pouring concrete footings is There are several methods for attaching
a simple job. Cement, sand, gravel and posts to the footings. Metal post anchors,
water mixed in a wheelbarrow can be wood nailing blocks, steel straps and
poured into a mold without much difficulty. drift pins are common methods. Metal
Builders can make their own molds or buy anchors are recommended for high decks
forms, such as Sona Tubes, at building while wood nailing blocks are suitable for
supply stores. low decks.
Placing the footings is key to the deck s
stability. The number of footings and posts
needed depends on the size of beams. In
general, deck builders like to use heavier
beams to minimize the number of foot-
ings. The placement of footings can be
calculated from the suggested beam and
joist spans.
15
7 12
14
9
11
5
6
13
10
16
1
4
2
3
8
1 Metal post anchor set in concrete 9 Ledger
2 Wood nailing block on 10 Butt-jointed beam with t-strap
pre-cast footing 11 Lapped joist
3 Drift pin post attachment 12 Joist hanger
4 Extended post with rail 13 Blocking
5 Built-up beam with 1D 2-inch spacers 14 Random length decking
6 Metal post/beam connector 15 Rail cap
7 Rim joist and fascia 16 Toe clip
8 Paired beams bolted to posts 17 Joist spliced with wood cleats
Beams Joists Decking
Beams rest on the posts and support the Joists rest on the beams and support the Decking provides the surface and walking
joists. They are installed  on edge with decking. They are installed  on edge with area of the deck.
the narrow side resting on the post. For the narrow sides resting on the beams.
Redwood 2x4 or 2x6 dimension lumber
some low decks, beams may rest directly At the side of the house, joists may be
is ideal for deck surfaces. Decking spans
on the footings. Beams of 4x6 and supported with a ledger. The distance
are described below. Extra weight, such
greater are common. Often beams are that joists may span is determined by
as a large permanent planter, a hot tub or
 built-up from thinner dimension lumber their dimension and the spacing between
spa will need extra support. In some cases,
by fastening them together with bolts or the joists.
it may be necessary to get assistance
lag screws.
Joists are often nailed to the top of beams from a contractor, architect or engineer.
The dimensions of beams depend upon and ledgers. With this design, the joists
With random length decking make sure
their spacing and the distances they need can overhang the beam for a cantilevered
the ends meet over joists. Decking should
to span. Larger beams require fewer appearance and added space, but the
be fastened with only one nail or screw
posts and footings. Sometimes it may be overhang should never exceed one-quarter
per bearing. This permits some dimen-
necessary to butt-join beams over a post. the joist span. A popular alternative is to
sional change in the decking yet provides
They can be spliced together using cleats hang joists from beams with metal joist
enough holding power. Extra nails may
made of smaller lumber or by using a hangers. This permits joists to be hung
be added later if necessary. Predrill nail
metal t-strap. level with or below the top of beams.
holes at the end of decking to avoid
Beams fasten to the tops of posts by For standard decking, joists should be splitting while nailing. For a cleaner look,
metal post connectors. Another method spaced 24 inches on center (from the use a hidden deck fastening system.
uses double beams which straddle the center of one joist to the center of the
Since it is the most visible part of the
posts and are attached with heavy lag next). For diagonal decking, joists should
structure, it is often desirable to add
screws or carriage bolts. This method be 16 inches on center. When installing
a design element to the decking.
is ideal where posts rise above the 5/4-inch decking, joists should be spaced
Decking can be applied in a variety of
deck to support a railing, seat or over- 16 inches on center and for diagonal
patterns including: diagonal, herringbone
head structure. decking, the spacing should be 12 inches
and parquet.
on center.
In cases where beams rest directly on
Suggested Decking Spans
footings, they are held in place by anchor Blocking nailed between the joists will
The suggested span for 2x4 or 2x6
bolts or by toenailing into nail blocks. increase the stability of the deck.
decking is 24 inches. If the decking is
Ledgers do the work of beams where the
Suggested joist spans to be installed diagonally, joists should
deck joins the house. The ledger should
For non-stress graded redwood lumber be spaced 16 inches on center. Spans
be bolted into the house framing or into
(Construction Heart) with live load of for 5/4-inch decking are 16 inches on
the concrete foundation. Fasteners should
40 lbs. per sq. ft. center, and 12 inches on center when
penetrate at least 11D 2 inches into the fram-
installed diagonally.
ing or foundation. Use metal flashing to
Joist Joist Joist
Decking to Cover 100 Square Feet
protect the ledger from moisture or use
Size Spacing Span
spacers between the house and the
2x6 16'' on center 7'3''
ledger to allow for water drainage. Materials Standard Diagonal
24'' on center 6'0''
Linear Ft. Linear Ft.
Suggested Beam Spans 2x8 16'' on center 10'9''
2x6 Decking 210 242
For non stress-graded redwood lumber 24'' on center 8'9''
2x4 326 375
(Construction Heart), with a live load of 2x10 16'' on center 13'6''
40 lbs. per sq. ft. and dead load of 10 lbs 24'' on center 11'0''
per sq. ft.
Deflection limited to L/240.
Beam Beam
Spacing Sizes
4x6 4x8 4x10
Span Span Span
6 feet 4'0'' 5'0'' 7'3''
8 feet 3'3'' 4'3'' 6 3''
10 feet 3'0'' 3'9'' 5'6''
12 feet 2'9'' 3'6'' 5'0''
Beam span is the distance a beam
extends from one post to the next. Beam
spacing is the distance between beams.
Deflection limited to L/240.
A staggered nailing pattern permits slight
 movement during the wood s natural
seasoning process while holding the
decking in place.
Construction Tips
Sometimes, enthusiasm can get builders
into trouble if they don t think about the
consequences. Overnailing, for example,
is a common mistake. One deck nail or
screw per bearing is fine for redwood
2x4 and 2x6 decking. Drive deck nail or
screw flush with deck surface; do not
countersink. Redwood shrinks less than
most wood, but unseasoned redwood
will shrink as the internal moisture evapo-
rates. If it is held down with too many
nails, decking may split when it shrinks.
Trapped moisture is another potential
troublemaker to consider. Wood decay is
caused by alternate moist and dry condi-
tions. Consequently, the areas that trap
moisture are the most critical. For exam-
ple, the place where posts meet footings,
or ledgers are attached to the house are
moisture-problem areas. These members
should be all-heartwood redwood and
they should be pre-finished with a water
repellent preservative solution. Decking,
because it is quick draining, will not be
as critical, but remember to leave about
a 1/8-inch space between deckboards for
drainage.You can use 16-penny nails as
spacers and they are usually the handi-
est measuring tool when you are apply-
ing the decking.
The Finishing Touch
There are many details that can help
turn a plain deck into an  aaaahh deck.
Some finishing touches, like stairs and
railings, may be absolutely necessary
while others, like benches and planters,
are simply a matter of taste and style.
As you are working, you ll notice other
little things you can do that will make the
deck  just right. For example, a fascia
trim around the edge of the decking will
give it a more finished look. Chamfered
or roundover edges can soften the
appearance of the deck board ends and
edges. Or maybe you d like to use mitered
corners for your railing. Or add built-in
shelves or cabinets.
Stairs Railings Benches
If the deck is over a foot off the ground, Although the railings are often the last Benches aren t hard to build if a few
you ll need to build stairs. Stairs require of the finishing touches, they need to basic rules are kept in mind. The best
precision carpentry and quality materials. be planned in advance. Consult local height is between 15 and 18 inches.
Decay resistance is important, so an all- building codes for railing requirements. Cushions change the measurement, so
heartwood grade should be used. Railings are necessary for any deck keep a ruler handy. Garden grades are
over 11D 2 feet off the ground. In many economical and work well for benches.
Stairs are made with treads and stringers,
areas a railing is required by law. For the
sometimes called risers. The treads are Here are plans for two different types of
most part, form should follow function.
the stepping surface and are supported benches. The first is built-in and is an
by the stringers. Stair treads should be a Remember to design a railing that extension of the deck railing. The second
minimum of 11 inches deep and between doesn t encourage sitting unless it is is a simple movable bench which can be
6 and 7 inches apart. For wide stairs, intended for that purpose. Railings built in a matter of minutes.
notched stringers placed 24 inches apart should be sturdy barriers erected at the
Bench #1 This built-in bench is part of
provide proper support. If only two steps deck s edge without completely obscur-
the railing. The length of the back and
are planned, a 2 x12 can be laid on edge ing the view.
seat boards can vary according to your
or notched as a stringer. If more steps
Railing supports should be securely plan. The seat supports shown in the
are needed, a sloping stringer should be
fastened to the framing of the deck. Toe- cross section below should be repeated
used. According to most building codes,
nailing to the surface of the deck is not every two feet. Many variations are possi-
notched stringers must have a minimum
adequate. Railing supports should be ble since railings double as bench backs.
of 31D 2 inches of width below the notch.
bolted to joists or beams, or they may be The seat slats are 1x2 boards set on
As an alternative, stair treads can be an extension of the post. edge and spaced 1D 2 inch apart. Bench
set inside a pair of stringers, so that the supports extend from the railings 2x6
Vertical grain redwood is suggested for
stringers enclose them on both sides. posts which are, in turn, bolted to deck
the cap of a deck rail because it best
This is referred to as  boxed stringers. joists and beams. The horizontal bench
resists weathering and splintering.
The tread can then be supported by supports are pairs of 4-foot 2x 4 s
cleats nailed to the stringers or by a between which posts and legs are sand-
separate notched stringer. Stringers wiched. Each leg is attached to the deck-
should be 24 inches on center to provide ing with a metal angle bracket. Be sure
proper support for the treads. the railing is strong enough to support
the bench and the weight of people
At the top, anchor the stringers to the
leaning against the back of the bench.
deck framing. At the bottom, anchor them
to the deck at the lower level or rest them Bench #2 This simple bench takes
on a concrete pad or footings. three saw cuts and a short time to build.
It is made from an 8-foot 2 x12 and is
braced with a 2x 4. Cut two 14-inch
pieces from the plank s ends for legs,
leaving a seating area 68 inches long.
Center the 2x 4 brace between legs and
attach with 16-penny nails. Attach legs to
the top by toenailing from below. If unsea-
soned lumber is used, assemble brace
and top with deck screws.
Bench #1
2 ' 4
2 ' 6
205/8''
1 ' 2s With 1/2'' Spaces
16''
2 ' 4
2 ' 4 Decking
Metal
Angle
2 ' 6 Joist
Bench #2
68''
8'' 12'' Min.
2 ' 12
14''
2 ' 4 ' 48 41D 2''
Finishes
Finishes will enhance the performance of
any exterior wood project, so it is important
to coat all surfaces with a water repellent
Redwood Finishes
wood preservative before installation.
Uses
For example, it is necessary to coat
sawn ends of posts and the back sides
Decks/Walkways
     
of ledgers before they are put into place
Fences
     
and hidden by other parts of the deck.
Planters/Retaining Walls
     
Clear Water Repellents Clear water
repellents with mildewcide can stabilize
Seating
     
redwood s color at a buckskin tan if
Tables
  
applied regularly.
Garden Shelters
  
Bleaching Oils Unfinished redwood
tends to darken, then ultimately weathers Effect
to a soft driftwood gray. To achieve an
Color Natural Driftwood Selected Selected Selected
  
immediate weathered appearance, a
Grain Visibility High Medium Medium None None
bleaching oil can be applied.   
Application
Decking Stains To achieve a lasting
redwood color or any other hue, a water
Recommended Coats* 2 1-2 2 2 2
  
repelling, oil-based deck stain may
Primer Required None None None None Oil/Alkyd
  
be used. Be sure that the stain is
recommended for walking surfaces. Refinish Years 1-2 2-5 2-5 5-10
     
Naturally Weathered Left unfinished, Non-toxic formulations Traffic bearing formulations Certified Kiln Dried lumber only
*Follow manufacturer s recommendations.
redwood will first darken and then will
weather-bleach to a soft driftwood gray.
Over time, this no-maintenance option
results in a look that is preferred for a
Fasteners
rustic appearance.
All nails, fasteners and hardware must be
Do
stainless steel, aluminum or top-quality,
Use water repellents, stains and
hot-dipped galvanized (electroplated
bleaching oils which contain mildewcide.
galvanizing is not acceptable). Poor quality
fasteners will react with redwood s natural,
Make sure all surfaces are clean and dry.
decay resisting extractives causing
Use a brush or roller for application.
unsightly stains.
Don t
Don t use varnishes or lacquers on
exterior redwood.
Don t mix incompatible finishes always
follow manufacturer s directions.
Don t use linseed oil alone as it will
attract dirt and mildew.
California
Additional Literature
Redwood
Redwood Fences For All Reasons
Landscape Architecture
Association
Deck Grades, Nails, Finishes
405 Enfrente Drive, Suite 200
Exterior Finishes
Novato, CA 94949-7206
Plans
Telephone [phone]
Freestanding Deck
Fax [phone]
Windsor Shade Shelter
Toll Free 888 Cal-Redwood
Mendocino Bench
www.calredwood.org
Sonoma Picnic Table
Petaluma Planters
Redwood our renewable resource
3/01
s/
wcides
hing Oils
aints
eathering
ater
x P
Milde
Semi-
Bleac
W
ransparent
/
Solid-Color
Lacquer
arnishes
T
and W
Repellents
Stains
Stains
Late
V
Stains
w