In this experiment, we are going to see if you can build a sandcastle, strong enough for bricks to stand on! How is this possible? The Let's Find Out gang are here to explain it all!!

The show is made with help from Science Foundation Ireland.

Watch it here now on the RTÉ Player!

Zoom wants to find out all about sand. So Evan and Rian show her the secret ingredient to building strong sandcastles! And then they test their sandcastle by loading bricks on top of it.

Download the lesson plan here...

You will need:

  • A sandcastle bucket (a round one if possible)
  • Sand
  • A spade
  • A pen
  • A scissors
  • Cooking mesh (available in kitchenware shops)
  • Something heavy, like small bricks or blocks

What to do:

  1. First you will need to cut out four pieces of mesh. Place your sandcastle bucket onto the mesh (open side down) and draw around it.
  2. An adult should help with cutting out the circle.
  3. Now repeat this three more times, if the bucket gets narrower towards the base then draw around the base as the second circle and cut it out. Then cut out two more circles, one a little larger than the base circle of mesh and the other slightly larger again.
  4. Now it's time to make the sandcastles. Bring everything outside and fill your bucket with sand, pack it down well, then turn it over on a flat surface and remove the bucket. You should have a nice sandcastle made.
  5. Test how strong the sandcastle is by carefully adding the heavy objects (like small bricks) one at a time to the top of the sandcastle. An should help as the sandcastle may topple when the load gets too heavy.
  6. Record how many bricks the sandcastle was able to hold before it toppled.
  7. Now make another sandcastle, except this time, add a little sand to the bucket, pat it down well, add the first piece of mesh (the smallest one if your bucket is tapered), add some more sand, pat it down and add the next piece of mesh. Keep going until all four pieces of mesh have been added into the sandcastle and the bucket is full.
  8. Turn over the bucket on a flat surface, as you did before and remove the bucket. You should have another nice sandcastle.
  9. Carefully add the bricks to the top of the sandcastle, one at a time.
  10. Record how many bricks this sandcastle can hold before it topples.

What’s happening?/The science bit:

Did you find that the sandcastle with the mesh could hold a lot more bricks than the regular sandcastle? That’s because you used something called friction to make this sandcastle super strong. The pieces of mesh made more friction between the grains of sand, allowing them to hold together more tightly, making the sandcastle stronger.

Also in this episode:
Mark and Amy make sand look like liquid...
And the whole crew go to the beach.

Check out the RTÉ Player to watch the full episode HERE and all the series so far HERE!!

AND there are lots more experiments with videos and full instructions - Just click HERE!