The details of layout and planning are essential to proper construction
of a building. Layout prepares the site for the foundation which must
be planned and completed for each building being constructed. This chapter
introduces the carpenter to the tools, materials, and techniques used
in the effective accomplishment of these vital layout and planning functions.
Layout techniques are described in the following paragraphs. The following
are the most commonly used
layout tools and materials:
· A string line is used to distinguish the dimensions of the
· A sledgehammer is used to sink corner stakes or batter boards
· A posthole auger is used to dig the holes required to set posts
properly in some soils.
· A handsaw is used to cut batter boards and posts.
· An ax or a hatchet is used to sharpen batter-board posts and
· A hammer is used for building batter boards.
· A chalk line is used to deposit chalk on the surface in order
to make a straight guideline.
· A 100-foot/30-meter tape is used for measuring diagonally (usually
in a 100 foot length) and for laying ou
excavation or foundation lines.
· Tracing tape is used for laying out excavation or foundation
lines. The tape is made of cotton cloth
approximately 1 inch wide. It usually comes in a 200 foot length.
· A carpenter's level is used to level a surface and to sight level
lines. It may be used directly on the surface
or with a straightedge.
· A line level has a spirit bubble to show levelness. The level
is hung from a taut line. It gives the greatest
accuracy when it is placed halfway between the points to be leveled.
· An automatic level measures approximate differences in elevation
and can establish grades over limited
distances. The landscape, level bubble, and index line are seen in the
· 8d nails are used to secure string line to batter boards.
· A plumbing bob is used to locate the corners of the building
· A framing square is used to check the squareness of lines.
LAYING OUT A RECTANGULAR BUILDING SITE
Working from an established line, such as a road or a property
line (line AB in Figure 4-1) that is parallel to
construction, establish the maximum outer perimeter (AB, CD, AC, BD) of
the building area.
Measure away from the front line (AB) along the side lines
(AC and BD) the distances (AO and BO) desired
to the dimension of the project that is to run parallel to the front line.
Stretch a line tightly from point O to
O. This line will mark the project's frontage.
Measure in from lines AC and BD along line OO one-half
between the length of line OO and the desired length of the project. The
points (X and X) will constitute the front corners of the project.
The two distances OX and XO establish the distances E and
Extend lines from the two front corners, X and X, parallel to AC and
BD at the distances established as E and F for the required depth of the
project. This provides the side lines of the project (XG and XH).
Joining the extreme ends of side 111 XH will provide the
rear line (GH) of the project.
After the four corners (X, X, G. and H) have been located,
drive stakes at each corner. Batter boards may be
erected at these points either after the stakes have been set or while
they are being set. Dimensions are
determined accurately during each step.
LAYING OUT AN IRREGULAR BUILDING SITE
Where the outline of the building is other than a rectangle,
the procedure in establishing each point is the sam
as described for laying out a simple rectangle. However, more points have
to be located, and the final proving
of the work is more likely to
reveal a small error. When
the building is an irregular shape, it is advisable to first
lay out a large rectangle which will comprise the
entire building or the greater part of it. This is shown in
Figure 4-2 as HOPQ When this is established, the
remaining portion of the layout will consist of small
rectangles, each of which can be laid out and proved
separately. These rectangles are shown as LMNP ABCQ,
DEFG, and IJKO in Figure 4-2.
SETTING BATTER BOARDS
Batter boards are a temporary framework used to assist
in locating corners when laying out a foundation.
Batter-board posts are made from 2 x 4 or 4 x 4 material; corner stakes
are made from 2 x 2s. Batter boards ar
made from 1 x 4 or 1 x 6 pieces.
Corner stakes are driven to mark the exact corners of the
Excavating for a foundation will disturb the stakes, so batter boards
are set up outside the boundary established by the stakes to preserve
definite and accurate building lines. Heavy cord or fine wire is
stretched from one batter board to another to mark these lines.
Location of Batter Boards
Figure 4-3 shows how to locate batter boards. Right-angle
boards are erected 3 or 4 feet outside of each corner stake. Straight
batter boards are erected 3 or 4 feet outside of the line stakes.
Construction of Batter Boards
Right-angle batter boards should be fastened to the posts
posts are sunk. Since the boards should be at the exact height of the
top of the foundation, it may be desirable to adjust the height by
nailing the boards to the stakes after the stakes have been sunk.
Right-angle batter boards may be nailed close to perpendicular by
using a framing square and should be leveled by means of a
carpenter's level before they are secured. Then, angle saw cuts may
be made or nails driven into the tops of the boards to hold the lines
place. Separate cuts or nails may be used for the building line, the foundation
line, the footing line, and excavation lines. These grooves permit the
removal and replacement of the lines in the correct
The following procedure applies to a simple layout as shown
in Figure 4-4, page 4-4, and must be amended to apply to different or
more complex layout problems:
Step 1. After locating and sinking stakes A and B. erect
batter boards 1, 2, 3, and 4. Extend a chalk line (X) from batter board
1 to batter board 3, over stakes A and B.
Step 2. After locating and sinking stake C, erect batter
boards 5 and 6. Extend chalk line Y from batter board 2 over stakes A
and C to batter board 6.
Step 3. After locating and sinking stake D, erect batter
boards 7 and 8. Extend chalk line Z from batter board 5 to batter board
7, over stakes C and D.
Step 4. Extend line O from batter board 8 to batter board
4, over stakes D and B.
Where foundation walls are wide at the bottom and extend
beyond the outside dimensions of the building, the
excavation must be larger than the laid-out size. To lay out dimensions
of this excavation, measure out as far
as required from the building line on each batter board and stretch lines
between these points, outside the first
The lines may be at a right angle where they cross the
corner layout stakes, found by holding a plumb bob ove
the corner layout stakes and adjusting the lines until they touch the
plumb-bob line. All lines should be
checked with a line level or a carpenter's level.
The two methods commonly used for squaring extended lines
are the 6-8-10 method and the diagonal method.
The 6-8-10 Method
After extended lines are in place, measure line EF for
a distance of 6 feet (Figure 4-4). Measure line EG for a
distance of 8 feet. Adjust the lines (Y and X) until FG equals 10 feet.
Multiples of 6-8-10 may be used for
large layouts; for example, 12-16-20 for a layout 50 feet by 100 feet.
For accuracy, never start with a
measurement of less than 6 feet.
The Diagonal Method
If the layout is rectangular, lines H and I, cutting the
rectangle from opposing corners, will form two triangles
as shown in Figure 4-4. If the rectangle is perfect, these lines will
be equal in length and the corners perfectly
square. If lines H and I are not equal in length, adjust the corners by
moving the lines right or left until H and