Popular Woodworking Magazine April 2010 #182

30"

48"

36"

60"

good furniture maker is part artist

and part engineer. An overemphasis

on either side of this equation leads

to furniture that is ugly, impractical or both.

Tables are especially vulnerable in this regard.

Tables serve many purposes and are simpler

than cabinets or chairs. But this simplicity

calls for a thorough knowledge of how wood

works when in the form of a large ﬂat surface

and an underlying structure.

Regardless of style, there are many mis-

takes lying in wait to spoil the plans of the

would-be table maker. Whether you are new

to the craft and getting ready to make your ﬁrst

occasional table or are more experienced and

aiming to build a showpiece for your dining

room, there are many aspects of table design

that you need to consider.

Shape and Size

The design process begins with establishing

practical parameters. A dining table needs to

accommodate a certain number of people on a

regular basis, and more on special occasions.

An end table provides space for a lamp and a

beverage, and an entry table may hold a vase,

the mail or your keys.

In addition to being the right size for its

use, a table must also ﬁt in the available space.

Seating 12 for Thanksgiving dinner is a worthy

goal, but not at the expense of daily navigation

through the dining room.

At this early stage of the process, a scale

drawing of the room or a 3D model in SketchUp

will allow you to consider alternatives. Chang-

ing your mind at this stage is much easier than

it is after you start cutting wood.

How Tables Work

B Y R O B E R T W. L A N G

Numerous shapes,

forms and functions

share a common set

of issues.

Form follows function. Tables of different sizes, made for different uses,

share a common set of engineering problems.

ILLUSTRATIONS BY THE AUTHOR

If you ﬁnd it difﬁcult to visualize things

on paper or on the computer screen, you can

mock up sizes and shapes with cardboard. Put

your idea together with packing tape, place it

in the room and live with it for a day or two.

You don’t want to invest the effort to build

the real thing only to hear, “I didn’t realize it

would be like that” from someone you love

when you’re done.

Consider also how shapes play a role. Rect-

angles are easy shapes to make, but sharp cor-

ners are painful reminders of too much table

in too little space. Rounded shapes are more

adaptable if you need to squeeze in an extra

diner or two, but will be more demanding to

build. Clipping square corners will protect

How many for dinner? A rule of thumb for seating is to allow 24"-30" per person around the perimeter

of the table. But you also must consider the shape and overall size of the table. Extra space is needed

at each corner, and while a narrow table may accommodate two settings across from each other, there

may not be room for serving dishes in between. There is no substitute for a scaled layout. More exam-

ples are online at popularwoodworking.com/apr10.

your hips or shins if you need to make the

most of a tight space.

For dining tables, a simple ratio of human

body to perimeter space rarely works. Con-

sider the available space at corners or across the

table, and how that affects the table’s function.

The drawings below give some examples, and

an article adapted from my book “Drafting &

Design for Woodworkers” (Popular Wood-

working Books), gives many more (see “Go

Online” at the end of the story).

Perfect the plan ﬁrst, then work on estab-

lishing the proper height for the structural

elements. Standard heights have evolved over

the years for the distance from ﬂoor to tabletop

for different types of tables. You may want to

40 ■ popular woodworking magazine April 2010

Coffee or

Cocktail Tables

16"- 20" high

18"- 24" deep

24"- 42" wide

End or

Lamp Tables

16"- 20" high

18"- 24" deep

24"- 42" wide

Sofa or

Entry Tables

28"- 42" high

12"- 18" deep

30"- 48" wide

Typical dining table is

29"-30" above ﬂoor.

Typical chair

seat is 16"-18"

above ﬂoor.

Space available for apron is limited.

Apron height of 2"-3" is typical.

Balance the need to support end of table with

clearance for feet. 10"-12" minimum, 16"-18" ideal.

“Figure-8” fasteners

swivel in partial hole

in aprons, allowing

top to move.

“Buttons” will slide in

slots in aprons,

allowing top to move.

30"

suggests a method to you that includes the

phrase, “that will keep it from moving,” be

aware that you are listening to a fool.

Wood movement can’t be controlled, but

it can be directed. In a dining table you can

screw the top to the base in the center and use

sliding fasteners on the perimeter to let the

top move equally toward each long edge. On

a desk, you can use a solid connection at the

front edge to maintain appearances and force

the results of the movement to the back.

In most tables, the wood grain will be in

line with the longest dimension of the table.

If you want an attractive table, use the widest

material you can ﬁnd and arrange the indi-

vidual boards for the most attractive appear-

ance. Historically, tables were made this way

without suffering any dire results.

The common advice to use narrow strips

and to alternate the direction of growth rings

may have some merit if you’re operating a large

vary the height to suit your needs, but consider

the consequences. Restaurants often provide

tables an odd height to make people uncom-

fortable so they won’t linger.

Desks and dining tables must also be able

to accommodate a chair, and the person on

the chair, with enough room between the

table and wall to get in and out. Compare what

you are considering to existing designs, and

spend a few minutes with a yardstick, a fold-

ing chair and a card table and you’ll ﬁnd out if

the dimensions you’re considering will work

in real life.

Start on Top

With the overall parameters of size and shape

established, stylistic and structural details are

next in line. Here is where the balance between

structure and style is most important. As you

develop your plan, consider the forces that will

be working against you. Considerations one

and two are movement of the top, and leverage

on the ends of the legs.

A solid-wood top will move across the grain

as the seasons change. Moisture (or the lack

of it) in the air will migrate to (or from) the

top and it will change in width. The number

of variables involved makes predicting how

much change will take place a guessing game,

but it will happen. This is a force that you can’t

control, but you can design around it.

In most table designs, the top and the base

are individual units that work together. The

connection between the two must be strong,

with some provision for the top to shrink and

swell. Cabinetmaker’s buttons and ﬁgure-8

fasteners are time-tested solutions. If someone

Irresistible force. Wood movement can’t be

stopped, but it can be accommodated. When

attaching a top to a base, use fasteners that will

slide or swivel.

No advantage to ugly. If you want an attractive

top, use the widest boards available and arrange

them for appearance (top). Gluing tops from

many thin strips with alternating end grain is

often presented as good technique. In reality, it is

more work, with more opportunities for failure-

and it makes an ugly top (bottom).

Standard is a range. This range of sizes for occasional tables is only a guide-

line; there are no laws in furniture design.

Tight squeeze. Dining tables and desks don’t leave much room for experi-

mentation. If in doubt, pull up a chair and grab a yardstick.

Go with the ﬂow. Attach the top to the base

structure with a method that allows the top

to expand and contract with ﬂuctuations in

humidity.

popularwoodworking.com ■ 41

Force applied to the end of a

typical table leg generates

leverage on the joints above.

Rails and stretchers

counteract leverage, but

interfere with legroom.

With narrow legs, space for

mortises is limited. Tenons are

mitered to allow for additional

length, not to ﬁt each other at

the ends.

Wider legs allow tenons

to be longer without

interference. Taper legs

below aprons to make

them appear lighter.

Mortises too close to

the edge will weaken the

leg. Size the components

of joints based on the

amount of material left in

place, not the amount

removed.

Tenons don’t have to

be centered. Moving

them away from the

face of the aprons will

leave more material

in the leg.

Glue the central mortise and peg the outer

mortises to accommodate the cross-grain

construction.

Braces across corners provide additional

strength with thin legs and aprons. Metal

brackets are available that can simplify

this joint.

Looks good, what do they do? Breadboard ends

might help keep a top from warping; they also

might keep elephants away. If you use them, take

care to attach them solidly.

The force may be against you. Table legs make excellent levers if there is no supporting structure near

the bottom end.

arrange the boards for appearance. You can

overcome surfacing problems by adjusting

tools and techniques, but you won’t be able to

change ugly. Let the wood acclimate to your

shop and carefully mill each piece as ﬂat and

as straight as you can. Establish a ﬂat surface

for gluing to minimize the work you need to

do on the assembled top.

Breadboard ends look nice, but their ability

to keep a top ﬂat is overstated. You won’t be

able to straighten out a large warped piece of

wood with a skinny straight one. In addition

to attaching the breadboard to the top with a

tongue and groove, add three or ﬁve tenons.

The tenon in the center is the only one that

should be glued. Allow room for movement

in the outer mortises, and use pegs to hold the

joint tight. Get used to the fact that the only

time you will see the end of the breadboard

ﬂush with the edge of the top will be the day

you make it.

A Sound Structure

The most common type of support structure

is four legs connected by aprons. This design

has been used for centuries, but there are weak

points. As long as a table is sitting still, skinny

legs and aprons are ﬁne. Put some pressure on

the bottom of the leg, however (think of drag-

ging a heavy table or kicking a leg as you pass

by), and there is enough leverage to break apart

the joints or the wood around them.

Mortise-and-tenon joints offer the stron-

gest connection, but two aprons intersecting

a leg at a right angle introduce complications,

especially if the legs are narrow. Rules based

on making a framed panel won’t apply for the

size and location of the tenons.

Size the elements of the joints so that plenty

of material remains around the mortises.

Tenons don’t have to be centered on an apron’s

Two joints, one space. Narrow legs leave little room for joinery. Mitering the ends increases the length of

the tenons; there should be a gap between them where they meet.

This has your back. No one that matters will ever

look behind the legs and under the top. Add a

wood or metal brace behind the corner if you

need to.

Size and location matter. How much material is

left around a joint is just as important as the size

of the joint. Don’t put strong tenons in weak legs.

Justiﬁable bias. Moving tenons to the back face

of a rail is one method to avoid a weak area

around a tenon.

factory, using suspect material and a ﬁnish that

will take the life out of the wood. If you’re care-

fully making one table at a time, this procedure

will lead you to do more work than necessary

to produce an ugly table.

Use the best material you can ﬁnd for the

top. It will be the prominent visual feature

of your table, and bad decisions during con-

struction will haunt you forever. I make tops

ﬁrst so I can pick the best material from what I

have available, and I usually spend more time

ﬁnding the right pieces to put together than I

spend in actual fabrication.

Match the color and grain patterns, and

42 ■ popular woodworking magazine April 2010

Span of legs should

equal 75-80 percent

of top diameter

Use hanger bolts in

ends of legs to

attach to pedestal

Rails between the legs

add strength, but

encroach on footroom.

Connect the

legs on a

diagonal and

you leave room

for your feet.

Combinations of

connections are

also effective and

add visual interest.

Many ways to make a connection. Look for a way to secure the legs without interfering with your feet.

“You can use an eraser on the

drafting table or a sledge hammer

on the construction site.”

– Frank Lloyd Wright (1867 - 1959)

American architect, interior designer & educator

thickness; they can be offset if need be. The

longer the tenon the better, and mitering the

ends of tenons that would otherwise intersect

gains additional length.

Dominos, dowels and biscuits are easy

alternatives for mortises and tenons, but won’t

be as strong or last as long. Of the three, Domi-

nos are the most durable alternative as they

most closely approximate a mortise-and-tenon

joint. Biscuits should be used in pairs to maxi-

mize the meat of the joint. Dowels may seem

strong enough in the short term, but over time

either the dowels or the holes for them will

move out of round and the joints will fail.

A brace at a 45° angle between the aprons

and behind the leg will not be seen and will

add support to smaller pieces. These braces

can be made of wood as seen in the drawing

on the previous page at bottom right, and held

in place with screws or other joinery. There

are also a variety of metal brackets available

that serve the same purpose.

Even the best joinery won’t eliminate the

effects of leverage. The addition of rails and

stretchers near the bottom of the legs will

form a stronger base, but the trade-off is in

both appearance and in use. More structure

equals a heavier appearance and interferes

with legroom.

On a desk or worktable, rails and stretchers

may not be a problem, but in dining tables this

can be an issue. Horizontal parts near the ﬂoor

make inviting footrests and are areas where

wear will quickly show.

Connecting rails can be like aprons run-

ning from leg to leg, or they can connect pairs

of legs. These rails are then connected to each

other by a stretcher running the length of the

table. A third method is to join the legs from

corner to corner, with the cross pieces joined

to each other in the center.

The best joint to use is a mortise-and-tenon,

but there are alternatives. A single dovetail

is effective for rails that join legs at the top of

the leg. This allows the rail to be thin, and the

wedge shape of the dovetail resists the outward

movement of the legs. Sliding dovetails are

traditionally used on small stands to join legs

to a central pedestal.

On a Pedestal

There are alternatives to placing a leg on each

corner. Tables that are square or circular can

be supported by legs attached to a central post.

Keep the footprint as large as is practical to pre-

vent the table from tipping if weight is placed

on one end. Imagine the ends of the feet to be

vertical legs to get an idea of how they will act

in their supporting role.

In small pedestal tables, such as the iconic

Shaker candlestand, the legs attach to the ped-

estal with sliding dovetails. In commercially

made dining tables, the typical connection

is with hanger bolts in the ends of the feet,

held firm with nuts on the inside of a hol-

low post.

At the top of a pedestal table, a plate wider

than the column is used as an intermediate

connection for the top. With small tables the

connection to the column can be a permanent

joint. For larger tables, it’s better to use screws

or hanger bolts, down to the column and up

to the tabletop.

To make a dining table extend, leave a few

inches of space between the base and the top

for an extension-slide mechanism. In most

extension tables, the grain direction is rotated

90˚ to run across the table. This avoids making

an end-to-end match where the two halves

join. A side-to-side match will be less obvious

when the table is closed.

While you could make your own slides,

buying manufactured ones has advantages.

Put it on a pedestal. A central column with

three or four feet is often a good solution in a

limited space.

Opportunity to over-think. In factory-made

tables, legs bolt on to a hollow pedestal. Small

pedestals often connect the legs to the post with

sliding dovetails.

popularwoodworking .com ■ 43

Tabletop must be thick

enough to provide stiffness

without additional support.

End assemblies must be

placed in from the end of

the tabletop to provide

legroom. The feet will

become footrests and

show wear and tear.

24"

16"

Small legs and ﬂush

aprons leave no room

for adequate joints.

Solid-wood top in mitered frame

will self-destruct due to seasonal

wood movement.

Space at end is too narrow

to accommodate chair.

Aprons too wide to allow

room for leg above chair seat.

34"

There is a lot of engineering and ﬁtting involved

in making a slide that will work predictably

for an extensive period of time.

Two types of slides are available: one for

pedestal tables and one for tables with legs.

The type for pedestal tables includes a gear

mechanism that equalizes the movement from

the center outward. The two types are also

crowned in opposite directions to compensate

for sagging as the table is opened. Equalized

slides raise slightly at each end in the open

position, and the other raises slightly in the

center. When the leaves are in place, the sur-

face will be level.

Get the hardware (or at least the actual

sizes) ﬁrst and engineer the table around it,

with the appropriate space between the base

and the top. Attach the slides with screws to

the top and to the structure below. If your

extension design incorporates an apron, attach

the apron to the top. The joint in the apron

will likely open as the top moves seasonally.

A small piece of trim to cover the gap, attached

to one apron only, is a common ﬁx.

The aggregate width of the leaves should

be a couple inches less than the opening range

of the slides. Short dowels with dome-shaped

ends will ﬁt the leaves to each other, and to

the tabletop.

On the Beam

Feet can also be placed laterally, and connected

by posts and beams to make a trestle table.

This time-tested alternative to four legs can

simplify joinery and make maximum use of

minimal amounts of material. Trestle tables are

essentially a series of connected I-beams.

Each end has an obvious “I” shape, but

looking down on the structure in plan view

reveals that the two ends connected by central

rails also form an “I.” The top in this scheme

often plays a structural role, connecting the

outer ends of the upper beams, thus keeping

the post-and-beam assemblies at each end

from twisting or racking.

Hybrid structures are often seen, and are

a good creative outlet. You can have a trestle

form at the base and conventional aprons at

the top. Whatever the form, keep an eye on the

structural elements. You want the table to be

strong and attractive, and you don’t want wood

movement of the top causing problems.

Structural elements will have an impact on

the appearance of the table. Elements associ-

ated with speciﬁc styles can look odd if placed

inappropriately. The proportions of the ele-

ments will also impact the overall proportions

and appearance of the ﬁnal design. Tapers,

bevels and curves can make parts appear

smaller or thinner than they really are.

The last illustration shows an unfortunate,

but common combination of design mistakes.

For a design to look good, it has to make sense,

and ignoring hundreds of years of techniques

isn’t wise. Learn the basics and build on a ﬁrm

foundation – then get creative.

PWM

Bob is senior editor of this magazine, and the author of

“Drafting & Design for Woodworkers” and several other

books. Visit his web site,

craftmanplans.com.

Beginner’s bad luck. Table design isn’t always intuitive. The drawing above shows several mistakes that

beginning table builders tend to make.

On the beam. Trestle tables are another alternative to four legs. Trestles provide a strong structure with a

small amount of wood.

Appearance can be deceiving. Proportions of individual components have an impact on the overall

perception of a design. These two tables are the same size, shape and basic structure, but make wholly

different design statements.

Go Online for more …

3D models of the tables in the opening illus-

tration are available for free download at:

u popularwoodworking.com/sketchup

For an article excerpt from “Drafting and

Design for Woodworkers” on dining table

shapes and sizes, visit:

u tinyurl.com/ybhanum

For a catalog of manufactured solid wood

table legs and kits, visit:

u tablelegs.com

To purchase the book “Drafting & Design for

Woodworkers”, visit:

u tinyurl.com/ybb2vxq

All of our online products are available at:

u WoodworkersBookShop.com

44 ■ popular woodworking magazine April 2010

⁄2"

⁄8"

18"

14"

⁄4"

⁄2"

⁄4"

⁄8"

⁄2"

⁄

16"

⁄

16"

⁄

16"

⁄

4" x 5"

side apron

⁄

4" x

⁄

front rails

⁄

4" x 5"

side apron

⁄

4" x 5"

back apron

⁄

4" x 1" drawer

guide at top &

bottom of apron

⁄

4" x 1" drawer

guide at top &

bottom of apron

A Good Example

f you’ve never made a table before, or if

you just need to exercise your table-

building muscles, this small Shaker side

table, featured in Issue 2 of

Woodworking

Magazine (Autumn 2004), is a good prac-

tice piece. The proportions are excellent,

the joinery is sound and it won’t require

a large investment in materials or time.

When you’re done you will have an attrac-

tive end table or nightstand.

The top is 18" square, and connects to

the frame with screws in oversized holes in

the upper drawer guides. If you choose not

to include the drawer, simply repeat the

joints from the back aprons at the front and

attach the top to the top edge of the aprons.

Starting with a good example is also a

good way to practice developing your own

designs. One secret to becoming a good

designer is to study many different existing

forms and experiment with them. Design is

a skill that can be learned through practice;

it isn’t a gift that some of us have and some of

us don’t.

A SketchUp model of this table is available

as a free download at popularwoodworking.

com/sketchup. If you have SketchUp installed

on your computer, you can download the

model and view it in three dimensions to

see how it goes together, or you can use the

model as a starting point for designing a simi-

lar table of a different size.

– RL

BACK LEG JOINT DETAILS

FRONT

LEG JOINT

DETAILS

SHAKER TABLE ELEVATION

TENONS AT

BACK LEG

DOVETAIL AT

FRONT LEG & RAIL

popularwoodworking .com ■ 45