Slab Tips

With the DIY craze, everyone wants to jump in and make their own piece of slab furniture like the one they saw on TV. Before you dive in however there are a number of things you need to know and understand.

  • All slabs warp during drying. This means that a slab needs to be surfaced flat before it can be sanded. No, you cannot run a slab through a big Timesaver sander and get it flat. This is like running a warped board through a planer. A warped board will still come out warped, it will just be smooth and warped. Slabs need to be surfaced flat on a CNC router or other means before sanding. This is a service we can provide.  If you would like to tackle it yourself then you will need to build a router sled. You can Google to find out what this is.
  • There are no straight or square edges on a slab. You will need to do the entire layout yourself and have the special equipment necessary to cut the edges and ends. This is not something you can do with a mere garage table saw or a chalk line and circular saw. You will need a track saw (like a Festool) or a large commercial table saw with a sliding table.
  • There is a LOT of sanding involved with slabs. We use a large commercial Timesaver sander and a large commercial Surcare sander designed for flat services. Even with our equipment we might spend 40 hours completing the average dining room table. With a small handheld sander from a home improvement store you will spend at least twice as much time.
  • You have to finish both the top and bottom of the slab. This means that if you put three coats of varnish or lacquer on top, you need to put three coats on the bottom as well. If you do not then the table will continue to expand and contract on one side but not the other. Your slab will warp drastically to the point it could become unusable. Wood is a living breathing thing long after it has been cut down and responds to changes in temperature and humidity. Seasonal movement alone from summer to winter and vice versa is enough to badly warp a table if not finished correctly.
  • Almost all slabs have defects like knots, cracks, splits, etc. We typically deal with these using bowties and epoxy. You will need a bit of experience to work with epoxy and the right conditions. It requires a bare minimum 60° to cure which means your cold garage workshop will not be sufficient. Below 50° epoxy starts to permanently freeze into a goopy semi solid and will not cure under any conditions.
  • You must allow for seasonal movement of a slab. On slabs over four feet wide they might change in size as much as 3/4″ when gaining or losing just a couple percent in moisture. If you try to constrain the movement with hard fasteners you will crack your slab or snap off your fasteners.
  • Whether you are buying a slab from us, or somewhere else, never, ever buy a “kiln dried” wood slab without proof of the moisture content.  If they refuse, or moisture metersay they do not have a moisture meter, then do not buy it, because they have no way of verifying their claim that it is kiln dried. Do NOT just take their word for it. A moisture meter is a very basic tool that every competent, legitimate seller of kiln dried slabs should possess. A slab dried to at least 6-9% moisture in the middle (NOT on the very end or on an edge of the slab) is generally ready to use. A slab with a moisture content in the upper teens or even the 20s is nowhere near dry enough and will warp and crack if you move it indoors.  A slab over 30% moisture is still soaking wet and above the fiber saturation point and has not even begun to even shrink yet. Unfortunately with the latest wood slab furniture craze there are all sorts of newbies coming out of the woodwork claiming to be selling thick kiln dried slabs that were cut only a month earlier. Never, ever assume that a “kiln dried” slab is at the proper moisture content. Do not just take their word for it. Buying a wood slab without verifying the moisture content is like buying a used car without taking it for a test drive. Demand proof or shop somewhere else.
  • A slab is generally safe to put inside after it reaches 6-10% moisture. Just like with lumber though, you will want to let it acclimate for a couple weeks before you make it into a piece of furniture.


If all this sounds way too complicated, then leave it up to us. We will transform your desired slab into a beautiful finished piece without all the headache.