The base decides whether the table stays still
A table top is a plate. It has no opinion about stability; the base does. When a guest leans on the edge of a table to stand up, the load goes into the base as a moment, and the base either resists it or the table lifts on the far side. That is the whole engineering question, and it is answered by two numbers: the mass of the base and the distance from the column to the outer edge of its foot.
Most table complaints in a restaurant are not about the top. They are about a table that rocks on an uneven floor, a table that shifts 20 mm every time someone leans on it, or a leg that is exactly where a guest wants to put their feet. All three come from the base choice, and all three are decided long before the top is specified.
The four types below cover the great majority of restaurant floors: cast iron cross base, four legs at the corners, trestle, and a steel plate or pedestal base. Each has a floor type and a room type where it is the right answer, and each has a cost that does not show up on the quotation.
Cast iron cross base: mass is the mechanism
A cast iron cross base works by weight. A 700 mm span cross in cast iron runs 18 to 25 kg on its own, before the column and the top. That mass sits low, within 60 mm of the floor, and it is what keeps the table planted when a guest pushes down on the far edge to stand up.
The trade is twofold. First, freight: a cast iron base adds 20 kg per table to the shipment, and on a 200-cover project that is 4 tonnes of billable weight that carries no design value on the floor. Second, floor protection: bare cast iron on tile will mark it within a week, so the feet need nylon or felt glides, and those glides wear through every 12 to 18 months in a busy room. Budget for a bag of spares with the original order rather than sourcing them later.
Cast iron cross bases suit round and square tops up to 800 mm, and they suit rooms where tables get moved. The four feet make the table easy to slide and hard to tip. Above 900 mm the cross has to grow to 800 mm span and the mass climbs past 30 kg, at which point staff stop moving the table and start dragging it, which is worse for the floor than a fixed base.
Four legs at the corners: maximum floor contact, minimum clearance
A four-leg base puts a leg within 80 to 100 mm of each corner of the top. That geometry gives the widest possible support polygon, so the table is stable without any added mass: a four-leg timber table at 22 kg total is as resistant to tipping as a pedestal table at 40 kg.
The cost is foot space. Four legs at the corners mean four legs in the seating zone. On a 700 mm square top, the legs sit exactly where guests put their feet, and the guest who pulls their chair in has to straddle a leg. This is why four-leg tables work best at 750 mm and above in width, and why they are the wrong choice for a banquette where the table edge is fixed close to the seat.
Four legs also need the floor to be flat. With four contact points, one high spot lifts a leg and the table rocks; a pedestal base with three or four feet under a 400 mm plate tolerates far more floor variation. On a timber floor over joists, or on a screed that has not been levelled to 3 mm in 3 m, specify adjustable glides with at least 10 mm of travel on every leg, or accept that staff will fold a napkin under one corner for the next five years.
Trestle bases: for long tables and communal seating
A trestle base is two A-frames or two verticals joined by a stretcher, and it exists to carry a long top. A 2400 mm communal table on two trestles at 1800 mm centres has a 300 mm cantilever at each end, which is inside the limit for a 40 mm timber top and well inside it for a 25 mm top with a steel sub-frame.
The advantage is leg clearance: with two supports instead of four, the space under the table is open, which matters on a communal table where guests sit along both sides and at the ends. The disadvantage is end stability. A trestle table loaded at one end will lift at the other, so trestles belong against a wall or in a run where the ends are not used for seating.
Stretcher height is the detail that decides whether a trestle works. A stretcher at 150 mm above the floor catches feet and mops; at 250 to 300 mm it clears a foot but reduces the bracing angle. Keep the stretcher bolted rather than welded if the table will be disassembled for events, and use a bolt with a nylon insert, because a plain nut works loose on a table that gets carried twice a month.
Plate and pedestal bases: the space-saving option
A pedestal base is a column on a steel plate: a pyramid plate at 400 x 400 mm, a disc at 400 to 450 mm diameter, both in 6 mm steel, with a column of 60 to 76 mm diameter. Total mass is 12 to 18 kg, so it is roughly half the freight of cast iron for the same top size.
The plate is what keeps the table up. A 400 mm square plate under a 700 mm round top gives 150 mm of overhang all round; push the top to 900 mm and the overhang becomes 250 mm, which is beyond what a 6 mm plate will hold without flex. The rule we build to is that the plate should span at least two thirds of the top dimension, and that overhang past the plate should not exceed 150 mm with a 25 mm top or 200 mm with a 40 mm top.
Pedestal bases are the right choice where the floor is tight and feet matter, which means small two-cover tables and any table where guests sit on three or four sides. They are the wrong choice where the table will be dragged: a pedestal table tips easily if lifted by the top edge, and the plate edge is the part that dents a skirting board. Weld a lifting handle under the plate, or accept that the plates will be chipped at the corners after a year.
Matching the top to the base
Overhang is where base and top decisions meet, and it is the most common source of a table that feels wrong without anyone being able to say why. Under 25 mm of overhang on the seating side and knees hit the frame. Over about 150 mm on a 25 mm top and the overhang acts as a lever, so the top flexes when a guest leans on the edge and the fixings at the column work loose.
Top thickness sets that limit. A 25 mm melamine-faced top on a chipboard core needs a steel sub-frame past 1200 mm span, and its overhang limit is roughly 150 mm. A 40 mm solid timber top carries 200 mm of overhang comfortably and spans 1400 mm between supports without visible sag. A 30 mm top sits between the two: fine to 1300 mm and 170 mm of overhang, provided the timber is at 8 to 10 percent moisture content when it is machined.
Edge profile matters more than people expect on a base decision, because a bullnose or a 10 mm radius edge is what guests actually touch when they stand up. A square edge on a 40 mm top reads as heavier and takes impact better; a chamfered edge on a 25 mm top reads lighter and chips sooner on the corner. Neither changes stability, but both change how the table is perceived next to the base you have chosen.
What to write in the specification
For each table type, the specification should carry: base type and material, plate or cross dimensions, column diameter and wall thickness, mass, glide type and travel, fixing method between base and top, overhang on each side, and the top thickness and core. Add the floor tolerance the base assumes, because a four-leg base and a plate base make different demands on the same floor.
Two production notes are worth adding. First, the connection between column and top: three or four bolts through a steel plate into the top core, with the plate recessed 3 mm so the table sits flush, holds better than screws into the underside of a 25 mm top. Second, the finish: powder coating at 70 to 90 microns over a phosphate base is what survives cleaning chemicals, and it is checked in our own restaurant furniture quality control before packing rather than at the port.
The models below show the four types in production sizes. The plywood-top table with pyramid plate base pairs a 6 mm pyramid plate with a 25 mm plywood top for rooms that move tables daily. The oak-grain table with pedestal base runs a disc plate under a 40 mm oak top, which is the combination we quote most for four-cover tables. The square slatted-top table with disc base uses an open slatted top over a disc plate, so a 700 mm square reads lighter than its footprint. Where a bay is not a stock size, the same bases are built into restaurant tables in custom sizes, and steel frames are available throughout our steel restaurant tables range for rooms that need the mass without the cast iron freight.