Simple Cement Bench:
What you will need:
2 x polystyrene boards (1200 mm x
1000 mm, at least 50 mm thick)
1 piece of shutterboard
½ bucket cement
½ bucket fine river sand
½ bucket 13 mm stone
3 mm reinforcement wire
Tape measure, pen, straight edge, rubber mallet, jigsaw, spirit level
1. Firstly, make the mould for the bench legs. On one of the polystyrene boards, measure and mark two identical rectangles measuring 550 mm x 355 mm, ensuring that the walls of the polystyrene mould are at least 150 mm wide. Cut these out using a jigsaw.
2. On the other piece of polystyrene, mark, measure and cut out a rectangle the size of your bench seat (400 mm x 900 mm), again with walls of at least 150 mm wide.
3. Create a wire reinforcing grid. Lay three strands just shorter than the length of the bench, about 400 mm apart. On top of these place three strands just shorter than the bench width, about 18 mm apart. Where the reinforcing wires intersect, join them using tacking wire. Check to make sure the grid fits easily into the seat mould.
4. Place your moulds onto a piece of flat shutterboard. Position the shutterboard out of the way and under cover so the moulds can remain unmoved until the concrete has cured. Mix 1 part cement, 1 part river sand and 1 part building stone, then add enough water for an easily pourable consistency. Pour a layer of concrete approximately 20 mm deep into the seat mould, then position the reinforcing grid on top of this and fill the mould with more of the cement mixture. Using a steel trowel, ensure the mixture is worked well into each corner and smooth the surface level with the top of the mould. Lightly tap the mould with a rubber mallet to agitate bubbles out of the mixture. Keep moist or cover and allow to cure for 2-3 days.
5. Pour the same mixture into the leg moulds, working it into the corners with a steel trowel. Smooth the surface level with the mould and agitate any bubbles out of the cement mixture using a rubber mallet. Keep moist or cover and allow to cure for 2-3 days.
6. When dry, wiggle the polystyrene mould off the bench legs and seat. If you are careful you can use the mould again and again. Sand any rough patches off the bench so your clothes don’t snag when you use it.
7. Choose a spot in the garden for your bench. Dig holes 150 mm deep for the legs, spacing them ±400 mm apart. Level the top of the legs with a spirit level and backfill the holes to hold the legs tightly in place, then position the bench seat. Job done! Sit and relax.