DIY GUY: concrete table top
- 4×8 sheet MDF wood, 1/2 in thick
- two 80 lb bagss of concrete counter top mix (we used QUIKRETE)
- silicone concrete sealant
- Box of 1 inch wood screws
- Steel mesh or rebar
- Mixing Attachment for Drill
- Measuring Tape
- Apron, gloves and rags for safety and clean up
1. Plan & Measure
Measure the area where you would like to install your counter top. Check for square corners and check for level. This will assure that your template is of the right proportions. Measure the area for the table top then cut the template based on those measurements. Test fit the template and ensure the fit is correct before building the mold. We used .5in mdf for our template as well as our mold.
2. Build your Mold
We wanted a 3 inch thick slab, so we constructed the mold with 3 inch tall side, making sure to pre-drill the wood screws so the mold panels do not slip or deform. Screw the mold box together constantly check to make sure everything is square and level.
We used .75 in MDF for this, the smoother the finish on the board the smoother the finish on the concrete. We wanted it to be a little bit rough so the non coated MDF is perfect. You can also use wood with the grain and the grin will show up on the top of the table top. For a smoother surface, we recommend MDF white melamine.
Seal the inside edged of the mold box with silicon sealer, smooth with you finger or a tool to remove excess sealer.
3. Mix & Pour & Shake
Using 1/2 bag at a time, mix concrete per instructions. Pour in the first batch and push it into the corners, making sure that all the corners are full and there are no clumps or air bubbles trapped.
Lay in the wire mesh, This add strength to the form.
Mix the rest of the concrete and fill the mold, smooth the top of the mold and ensure it is level and filled to the top. Once filled, tap on the mold with a mallet or shake the mold to remove trapped air bubbles. Let sit for 24 hrs
Carefully remove the sides of the mold, they should come a way freely, do not force them or pry them off as it will damage the concrete form. Once sides are removed, flip the form over and remove the top of the mold.
5. Sand, Polish, Stain or Seal
Sand the form with 150 grip sand paper, by hand or with an orbital sander. Be careful on the edges not to remove too much material. Knock down the sharp corner carefully.
Vacuum the dust and seal with concrete sealer.. You can also stain the form with concrete stain.
We sealed ours with a wet look clear coat, it has a realyl nice satin look! and is protected.
6. Placing your Finished Mold
Lift the super heavy form carefully into place. You can glue it down if needed. Ours was heavy enough that once we placed it, it didn’t move. Enjoy your new countertop!