How to Level a Pool Table
A pool table needs to be flat within roughly 0.01 to 0.02 inches across the whole bed, which is a quarter to a half millimetre over eight feet. Check it with a machinist level in five positions on the cloth: both ends, the centre, and both diagonals. Correct it at the leg levellers first, and use shims under the feet only once the levellers have run out of travel.
Level is the entire difference between a pool table and a piece of furniture with pockets. A table that is out by a hair sends every slow ball off line in the same direction, and the player quietly concludes they have got worse. They have not. The table is telling them which way the floor slopes, over and over, and it will keep doing it until somebody puts a proper level on the cloth.
The tolerance is roughly 0.01 to 0.02 in across the bed, about a quarter to a half millimetre over eight feet. A hardware store spirit level reads to about an eighth of an inch per foot, which is around ten times coarser than that. It will tell you a badly sloped table is perfectly level, which is worse than having no level at all, because you stop looking.
First, confirm it is actually the table
Before buying anything, do the rolling test, because it costs nothing and it tells you both whether there is a problem and roughly where it lives.
- Clear the table and brush the cloth with a proper billiard brush , always in one direction with the nap. Chalk dust and grit under a slowly rolling ball produce exactly the wander you are trying to measure, so eliminating them first prevents a false diagnosis.
- Roll a ball the length of the table as slowly as it will go without stopping. Use a good ball with no visible flat spot or chip. A cheap or damaged ball rolls off line on a perfectly flat bed, so if there is any doubt use a known-good phenolic ball as your reference and set the rest aside.
- Watch the last two feet, not the first two. A slope accumulates. Any push at the start dominates the beginning of the roll and has faded by the end, which is why the last stretch is where a real slope shows up cleanly.
- Repeat from the other end, then across the width, then diagonally. A ball that drifts left travelling one way and right travelling back is reading a genuine slope. A ball that drifts the same direction both ways is reading your release, or a ball problem, or grit.
- Roll along each cushion, a few inches out, in both directions. A drift that appears only near one rail points at one corner rather than at a whole-table tilt, which is a different and easier fix.
Repeatable drift in the same physical part of the table, from both directions, is a level problem. Random inconsistency that will not repeat is usually cloth, grit or a damaged ball.
The tool
A machinist level is the tool for this and there is no substitute for it. It is a ground steel body with a vial graduated so finely that a single division corresponds to a few thousandths of an inch per foot. Put one on a bed that a carpenter's level called perfect and it will typically show you something.
Two things about using one. First, it must sit on the slate, or on cloth over slate, and not on a rail. Rails are trim and are not a reliable reference for the bed. Second, always take a second reading with the level rotated 180 degrees in the same spot. If the bubble sits in the same place both ways, the reading is real. If it moves, the level itself is out of calibration and you have been chasing your own instrument.
A levelling kit that packages a level with shims and wedges is a reasonable way to buy this if you do not already own precision tools, and it is worth having permanently rather than borrowing, because this is a job you will do again every year or two.
The five measurement positions
Measure in a fixed pattern every time, and write the readings down. The pattern matters because a table can be level end to end and still be twisted, and a single reading in the middle will never reveal that.
- Lengthwise at the head end, level parallel to the long rails.
- Lengthwise at the foot end, same orientation.
- Crosswise at the centre spot, level parallel to the short rails.
- Diagonally, corner to corner one way.
- Diagonally, corner to corner the other way.
Record which way the bubble runs, not only how far. The direction is what tells you which foot to move. Two diagonals that disagree in opposite directions mean the frame is twisted, which is the case where you adjust one leg and everything else changes, and it needs to be worked corner by corner rather than by chasing the worst reading.
Correcting it
Step one: the leg levellers
Most tables have adjustable feet under each leg, threaded into the leg or into a plate. Find them first, because they are the intended adjustment and they are reversible. Work in small increments, a quarter turn at a time, and re-measure after every single adjustment. The two most common mistakes are turning a foot a full revolution because a quarter turn seems too small to matter, and adjusting two feet at once so you cannot tell which one did what.
Adjust the low corner up rather than the high corner down where you have the choice. Raising keeps every foot in contact; lowering can lift a diagonally opposite foot clear of the floor and put the whole load on three points, which produces a table that reads level and rocks.
Step two: shims
When a leveller has run out of travel, or when the table has no adjusters at all, the answer is a shim under the foot. Purpose-made table shims come in graduated thicknesses and are the right thing to use, because they stay put, they do not compress over a season the way a folded piece of card does, and they spread the load rather than denting the floor.
Two people make this much easier and much safer. One lifts the corner just enough to relieve the foot, using a lever against a protected floor rather than a hand under the frame, while the other slides the shim. Never lift more than a fraction of an inch, and never lift two corners at once. Lifting a fully assembled slate table beyond that puts the whole weight into a frame that was designed to carry it downward, not to be picked up.
Step three: re-measure everything
Every correction changes every other reading, so run the full five-position pattern again from the top after each change rather than only re-checking the corner you touched. This is why the job takes an hour rather than ten minutes, and why writing the readings down is worth the trouble: the pattern of numbers converging tells you that you are making progress, and a pattern that will not converge tells you the frame is twisted and needs a different approach.
What levelling cannot fix
- An open or badly waxed slate seam. If a ball audibly ticks or visibly deflects at the same line across the table every time, that is a seam and not a slope. The fix is re-waxing the seam, which means lifting the cloth.
- Loose or dead cushions. If a ball comes off a rail with much less energy than off the other rails, the rubber is dead or the rail is loose. That is a re-rubber or a bolt check, and it is covered in pool table maintenance.
- Worn or dirty cloth. A worn track down the middle of the table changes speed and line and reads a little like a slope. Replacement worsted cloth is the fix, and it is a fitting job rather than a home one.
- Damaged balls. A ball with a flat spot or a chip rolls off line on a perfect bed. Test with one known-good ball before condemning the table.
Keeping it level
A table that will not stay level is usually reporting a moving floor, and the cheapest fix is upstream. In a basement or any room below grade, a dehumidifier held at a steady 45 to 55 percent relative humidity does more for level than any amount of shimming, because it stops the joists and the table's own hardwood frame from cycling. The full case for this is in humidity and climate control.
Check twice a year on a wood floor, at the two changes of season. Check annually on a slab. Check immediately after any flooring work, after anything heavy is moved in the room, and after the first heating season with a new table, which is when a new installation most commonly settles.
Keep a fitted cover on the table between sessions. That does nothing for level directly, but it keeps the cloth clean, and clean cloth is what lets you trust the rolling test as a diagnostic instead of second-guessing it.
When to call the installer instead
Three situations. A brand new table that will not come flat, which is a warranty conversation rather than a shimming one. A table where the diagonals disagree badly and will not converge, which points at frame or slate rather than floor. And any table where the fix would involve lifting the slate or the cloth. A call-out is not cheap but it is a small fraction of what a cracked slate costs, and a cracked slate is not repairable in any way that matters.
Related
Installation itself is in pool table installation cost, ongoing care in pool table maintenance, and the whole-table move in moving a pool table. If you are checking a table before buying it second hand, the checklist is in buying a used pool table. Tables themselves are compared in the pool table roundup, and the accessory list is in pool table accessories.
Frequently asked questions
How do I know if my pool table is level?
Roll a ball slowly down the length of the table with no spin and watch the last two feet. A ball that drifts consistently to one side in the same place, from both directions, is reading a slope rather than a bad roll. Confirm with a machinist level placed on the cloth in five positions: each end, the centre, and diagonally in both directions. A carpenter spirit level is not accurate enough to find the error that ruins play.
How level does a pool table need to be?
Flat to within about 0.01 to 0.02 inches across the whole bed, which is roughly a quarter to a half millimetre over eight feet. That sounds absurd until you watch a ball travel eight feet: a slope you cannot see with your eye moves the ball an inch off line by the time it reaches the far cushion, and that inch is the difference between a pot and a miss.
What tool do I need to level a pool table?
A machinist level, which is a precision instrument with a vial graduated finely enough to read thousandths of an inch per foot. A 6 in Starrett or equivalent is the standard tool. A hardware store spirit level reads about an eighth of an inch per foot at best, which is roughly ten times coarser than the tolerance you are chasing, so it will happily tell you a badly sloped table is level.
Can I level a pool table myself?
Yes, for maintenance levelling of an already installed table, which is what most people need. Adjusting leg levellers or slipping shims under a foot to correct seasonal movement is a reasonable afternoon job with the right level and patience. What is not a DIY job is the original installation, which means moving 150 to 250 lb slate sections, setting and waxing the seams and stretching cloth, and that stays with a professional installer.
Why does my pool table go out of level?
Almost always the floor rather than the table. Wood floors and joists take on moisture in humid months and give it back when the heating comes on, and a framed floor can move several hundredths of an inch across a room through that cycle. Carpet compresses under a point load over months. Slabs settle. The table is simply reporting what the floor underneath it is doing, which is why a table on a basement slab with a dehumidifier running rarely moves and one on a wood floor in an unconditioned room moves every year.
How often should I check the level?
Twice a year for a table on a wood floor, at the changes of season when the heating goes on and comes off, which is when floors move most. Annually for a table on a slab. Immediately if the roll changes, if anything heavy has been moved in the room, or after any flooring work. Checking takes ten minutes and knowing costs nothing.
Measuring your own room before anything is delivered? The Game Room Layout Planner is the paid version of these pages: 8 printable worksheets you fill in with your own numbers, plus the full PDF, $29.
How we work: we compare published manufacturer dimensions, the governing playing standards for each game, and reviews from owners who live with the equipment. We do not test games in person, and we say so on every page. Clearance figures here are researched guidance for planning a room, not professional advice: measure your own space, and have a slate table delivered, assembled and levelled by an installer rather than moving it yourself.