Installing Redwoold Deck Primer and Plans, Woodworking Tips, Guides, Articles, Magazines, Texts, etc
[ Pobierz całość w formacie PDF ]
Deck Construction
Redwood is a wood like no other and
decks built of redwood are unique in their
beauty and long-lasting service. There’s
a grade of redwood lumber for any part
of any deck—luxury decks, economical
decks, simple decks and decks that push
the limits of definition.
Deck building isn’t difficult. In fact, it’s a
perfect project for learning basic con-
struction skills. Your deck can be as sim-
ple or complex as you wish to make it.
The care taken in planning, choosing
materials, double-checking measure-
ments and adding personal finishing
touches will go a long way in making
your deck project look professional.
This booklet contains deck construction
techniques and specifications based on
decades of cumulative deck-building
experience. It does not provide plans for
building a specific deck, but it has valu-
able information that will help with any
deck project.
Planning A Deck
The first step in building a deck is to sur-
vey your yard and decide what problems
the deck can solve.
Do you want to level a sloping yard?
Create a central activity area? Upgrade a
side yard? Minimize landscape mainte-
nance? Make a barbecue or picnic area?
Whatever problems you solve, you’ll find
your deck is a clean, dry place to enjoy
one of the best sides of your home—
the outside.
In selecting a site for a deck, it is important
to think about privacy, safety, access to
the house and protection from wind,
noise and weather. Landscaping features
must also be considered.
Think about the seasons when the deck
will be used and the sun’s path during the
year. Often a southwestern or southeast-
ern exposure is a good choice to take ad-
vantage of the morning or afternoon sun.
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.
The Secret of Redwood’s
Long-Lasting Beauty
Redwood decks look better than decks
made of other woods and keep their
handsome appearance longer because
redwood is naturally stable. This means
redwood deckboards nail down flat and
stay in place resisting warping, cupping,
splitting and checking.
Yo u ’ll find that redwood lumber has two
predominant colors: cinnamon-red and
creamy yellow. The cinnamon-red wood
is heartwood and comes from the center
of the tree. The creamy yellow wood is
sapwood and comes from the portion of
the tree near the bark. Some redwood
grades are all heartwood while others
permit both heartwood and sapwood.
Garden Grades
Garden grades of redwood are tailor-
made for decks and they are not expensive!
They have knots which give them a rustic
look that blends well with landscaping and
other natural materials. Redwood garden
grades are available in dimensions from
heavy timbers 20 feet in length to light-
weight benderboard often used for edging
garden walkways. Grades that have the
word “heart” in the name are entirely
decay-resistant heartwood.
Construction Heart/Deck Heart
All-heartwood grade containing knots; rec-
ommended for work on or near the
ground and for posts, beams, joists and
deckboards. Deck Heart is graded for
strength characteristics and is available in
2 x 4 and 2 x 6 only.
Construction Common/Deck Common
Similar to Construction Heart and Deck
Heart except containing sapwood;
recommended for most above-ground
applications such as railings, fences,
deckboards and trellises. Deck Common
is graded for strength characteristics and
is available in 2 x 4 and 2 x 6 only.
Merchantable Heart
Most economical
all-heartwood grade, allowing larger knots
and some knotholes; used for retaining
walls and garden or utility structures on or
near the ground.
Merchantable
Same characteristics as
Merchantable Heart but containing sap-
wood; suitable for fenceboards, trellises
and above-ground utility applications.
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.
Architectural grades are the top of the
redwood line. These grades are usually
kiln dried to pre-shrink the lumber, but
they are also available unseasoned. Often
used for quality siding and interior panel-
ing, architectural grades can be used for
highly-visible landscape architecture
where maximum stability is necessary.
Clear All Heart
All-heartwood, free of
knots; recommended for highly-visible
applications like deckboards, railings,
overhead shade structures.
Clear
Similar quality to Clear All Heart
except containing sapwood; uses include
railings, fences, deckboards, benches
and trellises.
Heart B
All heartwood grade containing
limited knots and other characteristics not
permitted in clear grades; uses same as
Clear All Heart.
B Grade
Similar quality to Heart B
except containing sapwood; uses same
as Clear.
Grains
Lumber has either flat or vertical grain
depending on how it was cut from the
log. Garden grades are sold with mixed
grain patterns. To minimize cupping and
grain raising, flat grain lumber should
be used with the “bark side” up or
facing out. Vertical grain lumber provides
the smoothest surfaces for railings
and benches.
Sizes of Garden Grade Lumber
Surfacing and seasoning reduce the
dimensions of lumber. As a result, the
actual dimensions of all lumber are
different from the nominal dimensions.
The chart below lists the actual and
nominal dimensions of redwood garden
grades.
S4S Dry Sizes (Inches)
Thickness Width
Nominal Actual Nominal Actual
1
Vertical Grain
Flat Grain
11
⁄
16
2
1
1
⁄
2
1
1
⁄
4
1
4
3
1
⁄
2
2
1
1
⁄
2
6
5
1
⁄
2
8
7
1
⁄
4
Annual Rings
Bark Side Pith Side
10
9
1
⁄
4
S4S Green Sizes (Inches)
Thickness and Width
Nominal Actual
4
Seasoning
Seasoned or unseasoned garden grade
lumber is suitable and most economical
for decks and other outdoor projects.
Architectural grades marked “Certified
Kiln Dried” are pre-shrunk and have
superior stability. They are good for areas
requiring tight joints, such as outdoor
shelves, cabinets and detail work.
Textures
Redwood is generally available with a
smooth, planed surface on all four sides,
known as S4S. Larger dimension timbers
(4 x 4 and greater) are often available
rough. Surfaced lumber is best for
sitting and walking surfaces or areas
to be painted.
3
9
⁄
16
6
5
1
⁄
2
8
7
1
⁄
2
10
9
1
⁄
2
Specifying Redwood
When you order or specify redwood
lumber, it is important to list the following:
intended use, grade, seasoning, size
and
texture
.
For Example:
Redwood lumber for
(use) decking shall bear the Redwood
Inspection Service grademark and shall
be (grade) Construction Common,
(seasoning) unseasoned, (size) 2x6,
(texture) S4S.
Redwood
Grades
and Uses
Architectural
——— ——— ——— ———
Garden
——— ——— ——— ———
Knots
——— ———
Sapwood
———
———
———
———
Posts
——— ——— ———
———
———
Beams
——— ——— ———
———
———
Joists
——— ——— ———
———
———
Decking
——— ———
Rails
——— ———
Fenceboards
Benches
Planters
———
———
———
———
Trellises
Furniture
Suitable grade for use
Most economical grade for use
With the preliminary planning done and
the business of redwood grade, sizes,
seasoning and textures taken care of, you
can start thinking about the actual
structure of the deck. Decks are walking
surfaces held up off the ground by an
understructure. The deck must be strong
enough to support the weight of people,
planters, benches, snow or anything else
that might be placed on the deck. The
understructure of a deck can have some
or all of the following members:
footings,
posts, beams, joists
.
The
footings
sit on or are partially buried
in the ground.
Posts
are vertical members
that rest on the footings and support the
beams.
Beams
support
joists
, which are
usually spaced about two feet apart and
support the decking. The
decking
is the
surface of the deck.
Each member of the deck is important
in carrying the load and distributing
the weight evenly. Proper spans—the
distance between two supporting
members—make for a safe deck and
one that feels solid when you walk on it.
The following pages contain detailed
descriptions of each part of a deck and
techniques for putting them together.
Laying Out the Deck
Mark the area for your deck with stakes
and string. Consider all the points men-
tioned under “Planning” on the first page.
The deck perimeter can be laid out and
squared in any number of ways. For
example, if the deck is to extend from the
corner of a house, it is easy to project a
string line from the non-deck side of the
house. This line and the wall where the
deck will join the house form two sides of
the deck perimeter. Next, measure the
length of the deck from the corner along
the wall of the house. With the third corner
marked, the location of the last corner
can be determined by measuring from
these other established points.
The accuracy of any rectangle can be
proven by diagonal measurements
between the farthest corners. When the
diagonals are equal, the rectangle is true.
In some cases, the house or structure a
deck is attached to will be out of line. It is
usually best to make the deck conform to
the structure.
Another method for determining the accu-
racy of a right angle is to create a right-
angled triangle with sides 6 feet by 8 feet
by 10 feet (or proportionate measure-
ments). Using string, run two lines from a
proposed 90 degree corner. Measure and
mark points 6 feet from the corner in one
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.
House
Second Measurement
Projecting Lines From the Corner of
a House.
If A = B Corners Are Square (90°)
6'
8'
Checking an Angle Using a Right-Angled
Triangle.
Footings
Deck footings rest on the ground and sup-
port the deck posts. Footings may be
either concrete blocks, pre-cast pier
blocks or poured concrete pads. As a rule
of thumb, a footing should be about twice
the size of the post it supports. For exam-
ple, 4 x 4 posts should rest on 8 x 8 con-
crete footings.
Building codes are usually specific about
the form and placement of footings. In
general, they are required to extend
below the frost line and they should
extend above the ground to keep wood
posts away from ground moisture.
Mixing and pouring concrete footings is
a simple job. Cement, sand, gravel and
water mixed in a wheelbarrow can be
poured into a mold without much difficulty.
Builders can make their own molds or buy
forms, such as Sona Tubes, at building
supply stores.
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.
Posts
Posts are vertical members which rest on
the footings and support the beams. The
length of the posts is critical in establish-
ing the height of the deck. Plan ahead—
extended posts serve as a support for
railings, benches and overhead trellises.
Timbers 4 x 4 and larger are most often
used for posts. If large crowds, deep
snow or other heavy loads are expected,
or if the deck is elevated, larger posts
may be needed and cross bracing may
be necessary to prevent lateral move-
ment. Local building codes will answer
these questions.
There are several methods for attaching
posts to the footings. Metal post anchors,
wood nailing blocks, steel straps and
drift pins are common methods. Metal
anchors are recommended for high decks
while wood nailing blocks are suitable for
low decks.
Beams can rest on top of posts or double
beams can straddle the post. The double
beam method uses two pieces of thinner
dimension lumber. Sometimes this can
mean a savings. Naturally, if the double
beam method is used, the posts need to
be taller.
If a single beam is going to rest on top of
the post, the post top must be trimmed
carefully to make a solid seat for the
beam. Double-check measurements
before sawing. Measure and level the
post from a stable reference position.
Make sure the posts are plumb when they
are measured, installed and trimmed.
15
7
12
14
9
5
11
6
13
10
1
16
4
2
3
8
1 Metal post anchor set in concrete
2 Wood nailing block on
pre-cast footing
3 Drift pin post attachment
4 Extended post with rail
5 Built-up beam with
1
⁄
2
-inch spacers
6 Metal post/beam connector
7 Rim joist and fascia
8 Paired beams bolted to posts
9 Ledger
10 Butt-jointed beam with t-strap
11 Lapped joist
12 Joist hanger
13 Blocking
14 Random length decking
15 Rail cap
16 Toe clip
17 Joist spliced with wood cleats
Beams
Beams rest on the posts and support the
joists. They are installed “on edge” with
the narrow side resting on the post. For
some low decks, beams may rest directly
on the footings. Beams of 4 x 6 and
greater are common. Often beams are
“built-up” from thinner dimension lumber
by fastening them together with bolts or
lag screws.
The dimensions of beams depend upon
their spacing and the distances they need
to span. Larger beams require fewer
posts and footings. Sometimes it may be
necessary to butt-join beams over a post.
They can be spliced together using cleats
made of smaller lumber or by using a
metal t-strap.
Beams fasten to the tops of posts by
metal post connectors. Another method
uses double beams which straddle the
posts and are attached with heavy lag
screws or carriage bolts. This method
is ideal where posts rise above the
deck to support a railing, seat or over-
head structure.
In cases where beams rest directly on
footings, they are held in place by anchor
bolts or by toenailing into nail blocks.
Ledgers do the work of beams where the
deck joins the house. The ledger should
be bolted into the house framing or into
the concrete foundation. Fasteners should
penetrate at least 1
1
⁄
2
inches into the fram-
ing or foundation. Use metal flashing to
protect the ledger from moisture or use
spacers between the house and the
ledger to allow for water drainage.
Suggested Beam Spans
For non stress-graded redwood lumber
(Construction Heart), with a live load of
40 lbs. per sq. ft. and dead load of 10 lbs
per sq. ft.
Joists
Joists rest on the beams and support the
decking. They are installed “on edge” with
the narrow sides resting on the beams.
At the side of the house, joists may be
supported with a ledger. The distance
that joists may span is determined by
their dimension and the spacing between
the joists.
Joists are often nailed to the top of beams
and ledgers. With this design, the joists
can overhang the beam for a cantilevered
appearance and added space, but the
overhang should never exceed one-quarter
the joist span. A popular alternative is to
hang joists from beams with metal joist
hangers. This permits joists to be hung
level with or below the top of beams.
For standard decking, joists should be
spaced 24 inches on center (from the
center of one joist to the center of the
next). For diagonal decking, joists should
be 16 inches on center. When installing
5/4-inch decking, joists should be spaced
16 inches on center and for diagonal
decking, the spacing should be 12 inches
on center.
Blocking nailed between the joists will
increase the stability of the deck.
Suggested joist spans
For non-stress graded redwood lumber
(Construction Heart) with live load of
40 lbs. per sq. ft.
Decking
Decking provides the surface and walking
area of the deck.
Redwood 2 x 4 or 2 x 6 dimension lumber
is ideal for deck surfaces. Decking spans
are described below. Extra weight, such
as a large permanent planter, a hot tub or
spa will need extra support. In some cases,
it may be necessary to get assistance
from a contractor, architect or engineer.
With random length decking make sure
the ends meet over joists. Decking should
be fastened with only one nail or screw
per bearing. This permits some dimen-
sional change in the decking yet provides
enough holding power. Extra nails may
be added later if necessary. Predrill nail
holes at the end of decking to avoid
splitting while nailing. For a cleaner look,
use a hidden deck fastening system.
Since it is the most visible part of the
structure, it is often desirable to add
a design element to the decking.
Decking can be applied in a variety of
patterns including: diagonal, herringbone
and parquet.
Suggested Decking Spans
The suggested span for 2 x 4 or 2 x 6
decking is 24 inches. If the decking is
to be installed diagonally, joists should
be spaced 16 inches on center. Spans
for 5/4-inch decking are 16 inches on
center, and 12 inches on center when
installed diagonally.
Decking to Cover 100 Square Feet
Joist
Joist
Joist
Size
Spacing
Span
2 x 6
16'' on center
7'3''
Materials
Standard Diagonal
Linear Ft. Linear Ft.
24'' on center
6'0''
2 x 8
16'' on center
10'9''
24'' on center
8'9''
2 x 6 Decking
210
242
2 x 10
16'' on center
13'6''
2 x 4
326
375
24'' on center
11'0''
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.
[ Pobierz całość w formacie PDF ]