Build better tables: Rocking, warping, splitting and more!

Side-to-side rocking

Side-to-side rocking is the most common and prominent form of rocking in wooden tables.

It is fairly difficult to build a table that does not rock side-to-side.

Most tables have some form of side-to-side rocking, and a perfectly stationary table is only necessary for workbenches or tables with heavy objects on them, like machinery.

Front and back rocking

Front and back rocking is easier to address than side to side rocking.

Creating sturdy end assemblies, the two legs on one side of the table, will address front and back rocking.

Tabletop splitting

Wood expands and contracts more across the grain than along the grain.

For tabletops, this means that your table is going to try to sandwich together or spread apart along its width.

There will also be some wood movement along the length of the tabletop, but it will not be as prominent as the wood movement along the tabletop width.

It is best to allow for this wood movement to prevent splitting. Later in this article, we will go over how to allow for wood movement in tabletops.

To learn more about wood movement, check out my article “Wood movement 101”.

Tabletop cupping/warping

With changing seasons, humidity levels, and environmental factors, you tabletop may warp and cup over time.

The main ways to prevent tabletop warping and cupping are the either add an apron or breadboard.

Tabletop moisture stains

Wooden tabletops are prone to moisture stains that can come from the condensation from cups, plates, or from spills.

The best way to prevent this is by using a paste wax. However, paste wax may not be ideal in every situation.

Later in the article, we will discuss when and when not to use paste wax.

Unlevel table

An unlevel table can be due to a flaw in the design and construction of the table, or it can be due to external factors like an uneven floor surface.

To create a table that is suitable for changing environments, it may be necessary to include self-leveling legs.

Table leg stability

It is essential to create a table to withstand rocking motion. However, you will also want to have a table can withstand direct force upon the legs.

Table legs may accidentally be kicked or hit with a vacuum cleaner.

You want to have the needed stability to prevent the legs from collapsing.

Install cross bracing

Cross braces are braces that connect right angle corners of an apron with the table leg.

Cross braces limit movement with between the legs and are a very effective way to prevent table rocking.

Cross bracing is also preferred by many because it does not change the design or appearance of the table.

To learn how to create and install cross bracing, check out my article “How to create cross braces for tables”.

Connecting legs together

Connecting the table legs together is another effective way to prevent tabletop rocking.

The downside to connecting the legs together is that it will change the table design.

Connecting two legs on the same side of the table forms an end assembly and you will use a stretcher to connect two end assemblies together.

When creating end assemblies and stretchers, the wider the wood, the more stability it will give the table.

Bed bolted and pegged mortise and tenon joints

Additionally, bed bolted and pegged mortise and tenon joints for end assemblies and stretchers will keep the joints tight for years to come.

I like to use bed bolted mortise and tenon joints for the stretcher and pegged mortise and tenon joints for the end assemblies. This is so I can remove the stretcher and transport the end assemblies if needed.

Shrinkage and expansion are greater along the cross grain of wood. This means that a tabletop wood will move more along the width of the tabletop relation to the length. It is best to allow for wood movement to prevent splitting.

To prevent tabletop splitting, you should use slotted screws and wood slits, button and groove joints, metal shrinkage plates, rebates, and pocket holes when attaching a tabletop and installing bracing to a tabletop.

Button and groove joints

To attach an apron to a tabletop, you can create a button and groove that has a little bit of extra space to allow for wood movement. The button will be secured to the tabletop with a screw and connected to the apron by inserting it into the groove.

Metal shrinkage plates

Metal shrinkage plates can also be used to connect aprons to a tabletop. These plates have slotted holes to allow for wood to move without splitting.

You want to attach the tabletop to the vertical and horizonal slotted holes and the apron to the circular holes.

Pocket holes

Pocket holes can be used to attach aprons and bracing to tabletops.

Pocket holes and pocket hole screws are different from regular screws because they leave a pocket hole gap, have a base that is wider than the screw size, and an oversized shank hole. This allows for wood contraction and expansion without splitting the wood.

Rebated rail

The tabletop can sit in a rebated rail or groove in the table base. The rebated rail should have a small gap to allow for expansion and contraction of the wooden tabletop.

Rebated rail and drop in tops are more common in glass tabletops, but can also be used with wooden tabletops to allow for wood movement.

With changing seasons, humidity, and environmental conditions, wood will naturally want to cup and warp. Now it is safe to restrict this type of movement, in comparison to the expansion and contraction wood movement.

Additionally, wood is more likely to warp along the width of the board and not the thickness.

The two ways you can prevent cupping and warping in wooden tabletops is to create an apron, breadboard, or vertical stretchers for the table.

Using an apron to prevent cupping

You can attach an apron along the width and length of the tabletop to prevent cupping. When attaching the apron is it essential to use methods to prevent the wood from splitting.

I explained how to prevent splitting earlier in this article.

Using a breadboard to prevent cupping

A breadboard is a piece of wood that is attached to the ends of the table with the grain facing vertically.

Breadboards are ideal for preventing cupping and covering the edge grain of the table.

To install a breadboard, you should use either mortise and tenon joints or pocket hole joinery to prevent wood splitting.

Using vertical stretchers to prevent cupping

You can use vertical stretchers that extend along the width of the tabletop.

These stretchers should be attached to the tabletop with the width of the stretcher being vertical and the stretcher thickness being horizontal and directly attached to the tabletop.

This is so the stretcher will be less likely to warp itself.

An unlevel table may be due to human error in the construction of the table. Additionally, an unlevel table may be due to an unlevel flooring.

The easiest way to fix an unlevel table in either instance is to use self-leveling legs.

You will have to drill a hole in the bottom of the leg and attach it leg using screws.

Tables need to not only be able to withstand rocking motions, but the bottom of the legs need to also be able to withstand force.

Making sturdy legs can prevent the legs from collapsing if they are accidentally kicked or hit by a vacuum cleaner.

To create sturdy legs, you need to connect the legs together.

You can do this by using an apron, end assembly, or stretcher to connect the legs.

Connecting the legs will prevent a single leg from collapsing if kicked or hit.

In this article, we learned the common issues faced when building wooden tables. Some of the issues can be seen right after the build, like rocking and an unlevel tabletop. Some of the issues may not appear until months or years later, like warping and splitting.

It is essential to correctly design a table to prevent these issues from appearing now and in the future.

Thank you so much for taking the time to read this article and I wish you luck on your woodworking journeys!