You might want a taller table for a breakfast area or a deck. Rather than buying a new table, you may be able to extend the legs on one you already have to accommodate tall stools or taller chairs. The average height of a dining room table is between 70 cm and 75 cm (28 and 30 inches). A bar height table is between 82.5 and 105 cm (35 and 42 inches) tall. Extending table legs 17.5 cm to 30 cm (7 to 12 inches) is not complicated and will save you money because you are recycling a table you already own.
Preparing the legs
Turn the table upside down and remove any casters or leg protection, then turn the table to the side and place a mark 5 cm (2 inches) from the bottom of each leg.
Drill holes in the bottom of each leg up to the mark. If the table already has casters with stems, the legs will already have holes where the stems were and you may only have to use the drill to make the holes larger and slightly deeper. Sand the drilled area smooth.
Cut enough off of each pre-made unfinished table leg to make the height of the table between 87.5 and 105 cm (35 and 42 inches) tall. If the legs are decorative, try to cut them off in such a way that the legs will go well with the existing legs of the table. For instance, if there is a curve in the pre-made legs, cut them above the curve so that they will blend in with the table legs. Mark each pre-made leg 5 cm (2 inches) down from the top.
Drill holes to the mark in each pre-made table leg. Sand the drilled area smooth.
Attaching the extended legs
Cut the dowel pin into four 10 cm (4 inch) pieces and sand smooth the ends.
Turn the table upside down and place wood glue in the holes, enough to coat the sides and bottom of the hole. Place a 10 cm (4 inch) dowel pin in each leg. Coat the part of the exposed dowel pin with glue.
Deposit some glue in the bottom of each hole in each pre-made table leg. Place on top of the other end of each dowel pin and press together with the table legs. Place a sheet of plywood on top of all four legs so that each leg is under the plywood. Put the concrete block on top of the plywood to hold down the legs until thoroughly dry.
Use wood putty or filler the colour of the table to fill in the space around where the legs meet, making sure to use the kind of putty or filler that can be stained. Let dry, then stain the attached extensions to match the table.
If a 1.2 cm (1/2 inch) dowel pin is too large for the legs on the table, use a smaller dowel pin. For larger table legs, use a larger dowel pin and drill a hole with a hole saw drill bit (a saw toothed drill bit made for drilling larger holes, such as key holes).