Introduction

Here are easy to follow DIY instructions on how to build a seesaw. Older children can follow these steps with adult supervision. This DIY project is perfect for an adult and child to build together - and then play on together afterwards!

This seesaw is embedded in concrete inside a car tyre. This makes a good solid base, which is both movable and, because of the rubber-tyre base, won’t scratch decks, patios or other surfaces.

Read all the instructions below through completely before beginning your project. First... a little note regarding concrete...

A dabble into concrete:
For this project, use pre-mixed concrete if it is available. Most building suppliers stock handy pre-mixed bags of concrete, which contain a dry mixture of cement, gravel and sand, and only need water to be added. These bags are ideal for small concreting jobs, such as this one. The bags usually come in 25kg and 40kg sizes.

However, if you would like to know how to mix concrete yourself – see the chapter at the end for some instructions.

Materials and Tools

Instructions on Making a Seesaw

STEP 1 - Prepare the Tyre.
Make sure your tyre is ready. If there is any dirt to be washed off, do that now.

(Did you know – Tyres are measured in both metric and imperial measurements. For example, the tyre we used was 175/70 – 14. This means: the tyre is 175mm thick, with a rim that is 70% of that, and the hole diameter is 14 inches (360mm). Crazy, huh?)

STEP 2 - Mark and Drill the Holes
Collect the following parts (diagram below) and cut them to the right length if necessary:

• Galvanised water pipe,
• One pivot support spacer (90 x 35 x 340mm)
• Four pivot supports (Each support 70 x 45 x 500mm)
• The seesaw plank (190 x 45 x 3000mm)

Measure carefully and mark the drill holes. Ask an adult to drill the 13mm holes for you.

STEP 3 - Assemble the Support Unit

Line up the holes in the spacer with the lower holes in the four pivot supports. Put two coach bolts through and tighten them, ensuring the whole unit is square, not wonky. The base of the spacer should be about 90mm up from the base of the four pivot supports. This is to allow a good pad of concrete to go under the spacer and stop the unit breaking through the base of the concrete.

STEP 4 - Cover the Hole in the Tyre Base Cover over the hole at the base of the tyre with thin pieces of wood or stiff plastic. In this example, the sides of an old nail-box are used. The timber was about 10mm thick. Make sure that whatever you use doesn’t go so far into the tyre that it stops the concrete flowing in the base of the tyre rim.

STEP 5 - Prepare the Dry Mix
Put one bag of dry concrete mix into a wheelbarrow (or similar container). The mix can be either a 40kg bag of pre-mixed concrete or about three-quarters of a wheelbarrow of your own combination of cement and builder’s mix (as explained in the chapter, "How to Mix Concrete" below.) Use a spade to mix into a uniform consistency. A smaller spade is easier to work with than a bigger spade.

If you are mixing in an area that needs to be kept clean and free of concrete, make sure you have a waterproof work sheet or tarpaulin under the mixing area and the tyre.

STEP 6 - Start Adding Water

A 40kg bag of concrete mix will take about 6 litres of water, which is a little over half a standard household bucket. You may need more or less than this – follow the instructions on the pre-mix bag or cement bag. Add a little water at a time. Mix with the spade from underneath and fold over. Keep doing this and adding the water until it is a uniform consistency. (A bit like stony porridge.)

STEP 7 - Start Pouring Concrete Use a stirring spade to add the wet concrete to the tyre. Add all the concrete from your container.

STEP 8 - Place the Support Unit

Altogether you’ll probably need about two 40kg bags of concrete, depending on the size of the tyre. When the first mix of concrete has been poured, push the support unit in as far as it will go. Just stand it upright by eye. Don’t worry about getting it perfect at this stage. That will be done soon.

STEP 9 - Fill the Tyre with Concrete

Following steps 5, 6 and 7 again, mix enough concrete to fill the tyre up to the top of the inner rim. The concrete should be made pliable enough to run around the inside of the tyre and up to the top. If not, you may need a little more water, but add it slowly in small amounts. Now vibrate the concrete to ensure there are no air pockets. Bang the outside of the tyre with a hammer or heavy stick. You may notice the concrete level go down a bit as the air pockets fill up. You’ll have to top it up again if this happens.

STEP 10 - Square the Support Unit

Time to straighten everything up. Lay a straight piece of timber on top of the tyre against the front of the support unit. Then put a large set square on top of the timber against one of the support uprights. You’ll now be able to tell if the support uprights are at right angles to the tyre by comparing the uprights with the vertical edge of the set square. Make necessary adjustments.

STEP 11 - Check the Side is Square

Do the same on the side as you have just done to the front. The support unit should now be square (at right angles) to the tyre. In other words, when the tyre is on level ground, the support unit should be plumb (vertical). Smooth over the top of the concrete with a small block of wood and then come back in an hour or so and smooth over it again.

STEP 12 - Go Away... and Stay Away

Forget about it. Let the concrete cure (set) for a week. Avoid temptation to finish the seesaw the next morning when the concrete looks fresh and feels hard. If the weather’s warm, keep the concrete in the shade while it is curing and try to keep it moist for a day or so by spraying it with a hose every now and then. The slower concrete dries, the stronger it becomes. If concrete dries too fast, it can crack.

STEP 13 - Prepare the Plank

One week later, place the seesaw plank on a couple of sawhorses or a workbench. Draw a line across the middle of the seesaw plank. We are working on the underside of the plank, which means the plank is upside down.

STEP 14 - Draw the Lines

Measure 13mm each side of the centre line and draw another two lines, on each side. The distance between the two outside lines is approximately the outside diameter of the pivot bar.

STEP 15 - Hammer in Three Nails Hammer in three temporary nails on the outside lines that you have drawn. Place two on one line at the very ends, and one in the middle of the other outer line. They’ll hold the pivot bar in place so it won’t move while the pipe saddle clips are being screwed on.

STEP 16 - Place the Pivot

Place the pivot bar in between the three nails. Make sure the overhang of the pivot bar at each side of the seesaw plank is the same. Water pipe is measured by the inside diameter, therefore 20mm water pipe is really about 27mm in diameter across the outside of the pipe.

STEP 17 - Place the Saddle Clips Place four pip saddle clips on the pivot bar, two at each end.

STEP 18 - Make Holes for the Screws

If you wish, you can hammer a nail through each saddle clip hole and then take it out again. This will make a hole in the timber that will guide the screw and make the job a little easier.

STEP 19 - Secure the Saddle Clips

Screw the pipe saddle clips in place. If you have an electric drill that can put in screws, ask an adult to do this for you.

STEP 20 - Tidy Up

Take the temporary guide nails out. They’re no longer needed.

STEP 21 - Put in the Height Bolts Put two coach bolts in through the pivot support uprights, one each side. The pivot bar will rest on these bolts. There are two heights to choose from: the choice is yours.

STEP 22 - Put it All Together

Put the pivot bar (which is now fixed to the seesaw plank) in the slots between the upright support unit so that it’s sitting on the height bolts. The seesaw is now ready to use. Find a partner and have a go.

This project is taken from the book, "Mitre 10, DIY for Kids, Book One" written by Les Kenny.