Solid Wood Slab Table Tops: An Introduction

Paul Downs Case Study

Slab, live edge, free-form: there are lots of ways to describe a table made with large slices from a tree.  This is just one way to make a solid wood table top, but it’s a very popular option these days.  This case study will explain what a slab is and where you get them, and give you some idea of what they cost.

When we work with clients on live edge projects, we give them the option of choosing their own slab, or they can set a budget and we will recommend choices that will work. (I’m assuming that the shopping will be done via the internet.)  This post is intended to give you enough information to do it either way.


What is a slab?  How is it different from other kinds of solid wood?

Trees get cut into usable smaller pieces in three formats.  Ordinary lumber is made by cutting a log into a variety of smaller pieces, with the mix chosen to maximize the yield of useful sizes:

Tree cut into lumber

A tree cut into lumber.

Veneers are made by cutting a log into very thin slices with a knife:

Veneer

A tree cut into veneers. Lots of slices from each log!

Slabs are made by cutting a tree all the way through. (The traditional term for this: “en boule”.)  This preserves the natural edge of the tree and yields several thick slices.  Each one of these is a slab:

Slab in their original order

Logs cut en boule. Each is stacked with slabs in their original order

What’s so special about slabs?

People buy slabs because they like the natural appearance of the live edge, and the interesting characteristics of the wood:  the knots, the cracks, and the figure. Slabs are lovely to look at and lovely to touch.  In our world of highly engineered and polished artifacts, it’s a relief to see an object which hasn’t been transformed beyond recognition by the act of production:

Goodwin Procter table. Happy architect for scale.

An inherent aspect of slabs is that each is unique. After all, trees are individuals.  Each one grows differently from its near neighbors and all others of its species.  And, even within the set of slabs cut from a single log, there will be wide variation in size and appearance.  Look carefully at the cracks and overall shape and size of these three slabs from one tree:  

Three slabs from one tree. Note variation in cracks, knots, and shape.

As you can see, they vary considerably.  Take that into account when you look for slabs.  The one you fall in love with will not appear again. Temper your expectations accordingly.  

Shopping for slabs: Buyer beware!

Live Edge furniture is popular, and it’s not hard to cut a tree up into slices, so producers have popped up all over.  Many of these are fly-by-night operations whose products are of unknown quality. It’s critical, when purchasing any lumber, that the seller has cut and dried it correctly or there will be problems in fabrication and after delivery.  How to choose who to do business with?  Here’s my list of requirements:

  • The producer is a large, established lumber business that is used to shipping their product across the country.  The website should have a physical address, and a Google Map search (use satellite view) should show a substantial operation with large stocks of wood in the yard.
  • Producer cuts and dries their own wood. Also, the producer’s facility will include at least one kiln.
  • All slabs are kiln-dried, not air dried, and preferably shown sanded and wetted to give an excellent idea of the grain.
  • Producer’s website has search and sort features, to aid in finding particular species and particular thickness slabs. Inventory should be updated frequently.
  • The producer shows pricing for each slab.
  • Producer’s website shows current slab inventory, with multiple good photos of individual pieces. Good photos are taken with the board in a vertical position, preferably with both sides shown.  There should be a clearly visible ruler and/or dimensions marked on the board, or a person in the photo for scale.  Bonus points if the board has been sprayed with water to show the finished color and grain. Here’s a bad picture and a good picture:

Bad. Good.

The picture on the left came from a lumber dealer in Germany, showing me what I would get if I sent them $7000.  What will this look like finished?  Who knows?

The picture on the right came from my favorite source:  Berkshire Products.  They excel at every item on the list. There are certainly other producers out there who are just as good.  If you are considering a different source, use the checklist.  Most of all,  if you just want to see cool wood with all of the information you need to make a good decision, try Berkshire.

How much do slabs cost?  And why so expensive?

When you start looking at slabs, you may experience severe sticker shock.  Thousands of dollars for a chunk of wood?  Why? The primary reason is demand:  people want them, and prices are skyrocketing accordingly.  Contributing from the supply side is the difficulty of production.  Cutting a tree into slabs is the least efficient way to use it.  A given tree might produce 4 to 6 slabs, or a couple of hundred board feet of lumber, or several thousand square feet of veneer.

Also, solid wood is sold by volume, not area. Thicker pieces have more material.  

Slabs are cut in various thicknesses, from 1” to 3” or more.  So, the thicker the cut, the more expensive the slab will be.

In addition, wood has to be dried before it can be made into furniture. A common rule of thumb is that slabs of wood require a year of drying per inch of thickness.

How does all of this work out in real life?  Let’s say I wanted to make a walnut table top that is 42” wide and 96” long and 2” thick when finished.

  • If I used veneer, the cost of the walnut would be about $162.  
  • If I glued up solid walnut lumber, it would be $884.  
  • And if I decided to make this table out of slabs?  I went shopping and found a nice pair of walnut slices, without exceptional figure or features, that will allow me to make a top that size.  These guys:

Medium grade walnut slabs

Price for the slabs alone, without shipping?  $3037.  Ouch.  And that’s before fabrication has started.

Budgeting for Slab Tables

It’s entirely reasonable to set a budget first, and then find a slab that’s in that price range.  I would love to give you a quick rule of thumb, like the overall cost of the table, would be double or triple the slab price, but it doesn’t work that way.  The cost of a table base will be independent of the cost of the top, and the cost of finishing is mostly driven by the overall size of the table.

That said, here’s a reasonable formula:  The least expensive slab tables end up costing about $800 a foot in length, and there are many choices of different woods for $1200 a foot in length, and the super premium woods may drive prices closer to $2000 a foot in length.  Furthermore, truly spectacular slabs can cost more than that.

Strategies for saving money:

There are ways to save money when buying slabs for table tops.  They can be sorted into two groups:

Good Ideas:

1) Consider using a species other than walnut.  For some reason, everyone is crazy for walnut these days, but there are lots of other choices, costing a lot less per square foot.  Remember, each slab is different, and the species is the least important driver of the appearance of the finished product.

2) Buy a 2” or 2 ½” thick slab instead of a 3” or thicker slab.  Wood is priced by volume.  2” thick slabs will generally yield a top finished to 1 ½” to 1 ¾” thick.  That’s plenty for most tables.  If you do want a thicker top, just be aware that the extra bulk is increasing your costs.  (Note:  many lumber dealers measure wood thickness in quarters of an inch.  1” thick wood is called 4/4, 2” is 8/4, 2 ½” is 10/4, 3” is 12/4 and so on.  The most common cuts are 8/4 and 12/4.  The finished top will always be ¼” to ½” thinner than the stock you buy, as wood will be removed during fabrication.)

3)In addition, think carefully about how much wood you need.  As a result, accurate photos with dimensions are critical for this.  You don’t want to buy more or less wood than you need for a table of the size you want.

4) Also, think carefully about what features you like and dislike in a slab.  Wildly curved edges, knots, and cracks add character but also require more fabrication time and may affect the utility of the table.  Most of all, get the slab that will work for you.

Bad Ideas:

1) Don’t buy from the cheapest source.  There’s always a reason for that, and it’s usually because the wood is not dried properly or misrepresented, or the source is unreliable in some other way.

2) Don’t buy air dried instead of kiln-dried stock.  Unless it’s kiln dried, a slab will experience significant shrinkage, often accompanied by warping, during the heating season.  This can cause lots of problems when the table is put in service.  An air-dried slab may also have insects living it, which can cause all kinds of problems.  Kiln-drying kills insects.

3) Don’t buy very thin slabs.  Anything less than 2” thick prior to fabrication is not good for a large table.  Thin slabs don’t feel solid and are more likely to warp.

4) Don’t buy foreign sourced wood, particularly from Third World countries.  This is often less expensive because it’s being illegally logged, using very cheap labor.  Unfortunately, it may not have been dried correctly, either.  So, if you are concerned about sustainable forestry, stick with wood from the United States & Canada.  (These are the familiar species:  maple, oak, cherry, walnut, ash, sycamore, beech.)  Slabs are a very inefficient way to use a forest and almost always involve old growth.  Because, the US & Canadian are well managed, the trees there are growing faster than they are being removed.  And, you might qualify for local sourcing LEED points, too.

5) Don’t buy “seconds” slabs.  Many slabs suffer serious distortion during the drying process and end up dished, or warped, or with severe cracks.  Therefore, these pieces get heavily discounted.  This type of material is not suitable for large tables.  There are other types of defect which aren’t so bad, particularly small amounts of decay, as long as the wood has been kiln dried to kill any insects that were living in the wood.

6)    Don’t assume that the slab you priced in January will still be available in July.  As a result, the only way to ensure that a given piece of wood is available when you need it is to buy it right away.  Which can be a problem if you are only specifying a table and a budget, and not yet ready to place an order.

What I bought:

We’re working on two tables for our own office.  I’m using them as demos to show what can be done with slabs.  One would be made from a single piece of wood while the other would be made from a pair of slabs cut from the same tree. (This will allow me to make a wider table, which is useful for maximizing seating.)  In July of 2017, I fired up my browser and started browsing the Berkshire Products. website.  And, after a couple of hours, I ordered my slabs.  First, a very nice piece of ash:

Very nice Ash slab

This piece cost me $2401. It’s big enough to make a table about 9 feet long, averaging 44” wide.

My second purchase is a pair of American Elm slabs, seen here partially wetted to show their coloration:

American Elm bookmatched pair of slabs

The pair of slices cost me $1516. (That’s half the cost of the pair of walnut slabs seen above, for slabs of similar size and with a better figure.) And, shipping for both of these was free.  They’ve been sitting in my shop all summer, and now it’s time to make tables.  

In part 2 of this series, I’ll walk you through the design decisions I made before starting work. And, in part 3,  I’ll show you how we make a slab table.

An Introduction