3rd class were talking about materials used for building and were asked how we could stop damp from coming into buildings. This used to be a problem for their current classroom before the new school extension was built on. They provided possible solutions for this...maybe it's better insulated now, maybe it's because it's not an end wall on the building now.
We decided to investigate what materials would be good to keep the damp out. The materials used were kitchen paper, cardboard from an egg carton, brown paper from a shopping bag and plastic from a freezer bag. In order for the test to be fair, pupils decided that the size of the material being tested should be kept the same, as should the quantity of liquid poured into the test container.
Pupils made predictions beforehand, and they rated the ability of the material from worst to nest as follows: kitchen paper, egg carton card, brown paper, plastic.
For each material being tested, two sugar cubes were placed on the plate, with the material on top and then one more sugar cube on top of that. 50ml of water coloured with food colouring was then poured into the plate and timed to see how fast it would reach the top sugar cube. The pupils' predictions were correct, although the brown paper was much more damp-proof than expected. Most put this down to some type of coating being on the bag.