How to Make a DIY Concrete Sink

How to Make a DIY Concrete Sink

Why DIY? Of course, when you DIY concrete countertops, you’ll save the money that would be spent on hiring a contractor. What’s more, DIY projects tend to be much more rewarding than tasks contracted out—and who doesn’t want that kind of personal satisfaction! DIY concrete sinks are not entirely DIY if you contract out the installation to a plumber. DIY means you have a contractor for the rough-in, but DIY in this case means building and installing your own sink and countertop with the help of some DIY friends.

How to Make a Concrete Sink

There are several ways to build a concrete sink. You can use preformed fibreglass tubs or buy a DIY kit. You can even cast the sinks from a plaster mold, but this is absolutely not DIY.

If you have been putting off DIYing it because of time constraints, here’s an idea: why not DIY your own concrete countertop? In order to do so, you can pour and finish one half at a time and build up your DIY skills as you go.

Setting Up the Form for a DIY Concrete Sink A DIY concrete sink starts with an idea, and then some drawings to refine that idea into a plan. You have endless options when it comes to DIY counters though one of the simplest is also one of the most common: a rectangular box—essentially a DIY concrete countertop on a DIY frame.

DIY Concrete Sink
DIY Concrete Sink

For your DIY sink, you’ll want to start at least one day in advance with the building of the form. The best way is to build a two-part form: a plywood top and a Masonite bottom—you can screw or staple them together. That way if there is any leakage at all, it will be captured in the plywood form.

Now let’s get down to DIY concrete specifics. Your DIY concrete countertop should have a thickness of 1 to 3 inches, depending on how you plan to finish it—not including the final seal coat that will go over the entire sink and counter. The slabs are poured into, and then lifted out of the form.

You need two Concrete Countertop Mixes:

1 part Quikrete 5000 with 1 part fine sand (play sand).

2 parts Quikrete 5000 with 1 part aggregate.

This is for the topcoat, so you’ll need to add a little more water than usual in order to get it nice and smooth. Concrete Convenience: A Concrete Mixing Bag Rather than mix concrete in a wheelbarrow, invest in a $3 vinyl mixing bag each time you pour your countertops—it will save you tons of clean up and time down the road in cleaning your tools. Plus, when you’re done mixing Concrete Countertop Mix or Concrete Slab Mix, you can use the Concrete Convenience: A Concrete Mixing Bag to dispose of your mess by simply tossing it into your wheelbarrow.

How Deep Should a Concrete Sink Be?

The depth of a DIY concrete sink should be 20 inches from the top edge, including any frame. This gives you a place to set glasses and cups while giving enough space for full-size plates and pans. You’ll also need about 12 inches of clear space in front of the new countertop for appliances such as dishwashers and refrigerators.

Building Concrete Countertops From Slabs To build your DIY concrete countertop from slabs, pour them over a form—just don’t forget to leave 3/4 inch around the finished section for the sealer coat. You could even set your DIY Concrete Slabs on a DIY Concrete Countertop Frame to give them additional support if you like, and create a stronger bond.

The Concrete Countertop Sealer Coat

After pouring Concrete Countertop Mix over the slab forms, smooth out the surface with a trowel. Leave it to dry overnight—the top should be slightly damp but dry enough so that no water beads appear when you touch it.

Once it’s dry (overnight), wet down (not flooded) and then sprinkle on Concrete Countertop Mix in three applications approximately 24 hours apart. Then leave it alone until the Concrete Countertop Mix is hard enough to resist an imprint from a fingernail.

It will take a day or so to completely dry out—that’s OK. Concrete Countertop Mix cures from the inside out, so it will be much harder than the outer layer—stronger and more resilient as well. If you have any dings in your Concrete Countertop Mix, don’t fret—you can always touch them up later with Concrete Stain, Concrete Dye or Concrete Paint.

Three Ways to Finish Concrete for a DIY Concrete Sink

You can use one of three finishes on Concrete Countertop Mix: Polished Concrete – The fastest and easiest finish is polished concrete. This is a great option if you’re going to finish it with a sealer coat, Concrete Stain, Concrete Dye or Concrete Paint.

Concrete, Ingrained – In contrast to polished concrete, you can leave Concrete Countertop Mix just as it is—a little rougher around the edges. This finish is ideal if you plan on staining your Concrete Countertop Mix with a clear penetrating sealer coat.

Concrete Resin – If you want a truly indestructible surface for your DIY Concrete Sink, consider using a resin-based material over your Concrete Countertop Mix. Remember that all of these finishes are available from Cement Concepts in the form of concrete countertop mixes and concrete dyes as well as stains and paints

Ways to Finish Your DIY Concrete Sink

Concrete stain is a great way to colour Concrete Countertop Mix for DIY Concrete Sinks. You can even make your own Concrete Stain by mixing Concrete Dye with water. Concrete paint will give you an opaque finish, while Concrete Dye and concrete stains impart a translucent look that’s ideal for customizing the look of your DIY concrete sink.

To top it all off:

Mix in some aggregate when you pour Concrete Countertop Mix to add visual interest—you could use the same aggregate in both layers or different aggregates if desired. Remember that Concreting Around an Object such as a Toto toilet flange is not difficult at all when using pre-mixed Quikrete 5000.

Basics of Making and Pouring a Concrete Sink Mold

1. Make Concrete Sink Mold

Concrete is heavy, so you’ll want to build a 2×8 mould box for your concrete sink rather than trying to balance plywood, sheetrock or other materials on the subfloor below. Concrete moulds are rough-looking things, so don’t worry about making them look nice. The biggest concern with how the mould looks is whether it will provide support where necessary and keep any extra weight off your subfloor.

2. Use Concrete Mix Instead of Mortar

Concrete sinks are moulded in place; there’s no wheelbarrow involved. That makes it important that the form be rigid enough to hold its shape under pressure (from pouring) but also flexible enough to come apart (later). Concrete is too heavy to be supported on the subfloor itself, so you’ll want to build a form with vertical dividers (2 by 4s or 2 by 6s) between horizontal boards (1 by 12s or 1 by 8s), then reinforce the structure with concrete.

3. Build Concrete Sink Mold Frame

To construct your mould frame, start at the bottom using two straight 2×6 pieces of lumber placed parallel against each other on their narrow edges; these act as sills for your concrete sink mould. Place another piece cross-wise across the sills every 16 in., and finish up with a top sill that spans from one end of the assembly to the other. In order for water to drain away from the concrete sink, you must notch out a section in the sill that forms one side of the drain.

4. Add Concrete Sink Mold Form Boards

Concrete is heavy, so it’s important to reinforce your mould frame by placing horizontal boards (1 by 12s or 1 by 6s) between vertical dividers (2 by 4s or 2 by 6s); this means you’ll need to overlap each board horizontally with its adjacent framing member. The best way to do this is to notch out notches in the form every 16 in., then place two boards parallel against each other into these notches; screw them in place using 3 in. screws and washers. Finish up your mould by attaching another board cross-wise across the top.

5. Install Concrete Sink Drain

To keep your concrete sink drain in place, notch out a section of one of the lower form boards; then attach a 2×4 board horizontally every 16 in., nailing it into both this notch and an adjacent framing member (2 by 4 or 2 by 6). Create another horizontal support on the other side of the drain to help carry the weight, and offset this so that water will flow away from it down through the drain pipe.

6. Pour Concrete for Concrete Sink Mold

Concrete mix is available at most lumberyards and home centres; purchase a 40 lb. bag for each 60 sq. ft. you need to pour—for two bags, that’s the space inside your mould frame. The concrete mix comes with instructions for mixing, but remember that it’s always better to make concrete too wet than too dry (too much water creates weak concrete). Concrete curing takes time; you’ll need to keep an eye on it for at least three days after pouring if conditions are sub-optimal.

7. Remove Concrete Sink Mold

To remove your concrete sink mould, simply pry apart the boards and break out all nails or screws that held them together; then use a hammer to break up any large chunks of wood that remain attached to each other. For a smooth flat surface, grind down any remaining seams using a disk sander, then use a power washer and/or wire brush to remove any concrete that spilt over the top of your mould or was left on the surface. Concrete sink moulds are heavy, so make sure you’ve got a friend on hand to help you lift it off.

Related Posts