Is wood waterproof?

This is a fun activity I’ve done with a group of Year 1 children this week as part of their Materials topic to investigate whether wood is waterproof.

We talked about the materials we tested being waterproof or not and if they were absorbent or not.

Is wood waterproof

Is wood waterproof?


LEGO house with no roof

Materials to test – paper, wood, plastic etc

Water sprayer


First we chatted about the house needing a roof and what properties a good roof should have. We decided a roof should be waterproof.

I then asked the children to predict which of our materials would make the best roof.

We placed a piece of paper inside the house so we could easily tell if the water had leaked through the roof.

To keep the amount of water used constant we tested each material with 3 big sprays of water.


As correctly predicted by the children the paper was not waterproof and absorbed the water which then leaked onto the floor of the house, we also noticed that the paper tore easily when wet.


The wood was a tricky one, as the water didn’t pass straight through the wood to the floor of our house, but was absorbed by the wood, so it wasn’t waterproof.

The plastic was clearly waterproof, you can see here how the water beads on the surface.

is wood waterproof


To illustrate the different between the wood and water further, we set the roof to a sloping angle and observed the difference between the wood and plastic. Again the water was absorbed by the wood, but rolled straight off the plastic.

Things to think about

How could you improve the accuracy of this activity?

Should we have used the same thickness of wood, paper and plastic to make it a fair test?

Extension Ideas

Could you test to see how strong the different roof materials are?

Great for Key Stage 1 Science

Compare and group together a variety of everyday materials on the basis of their simple physical properties.

Identify and name a variety of everyday materials, including wood, plastic, glass, metal, water, and rock.

Describe the simple physical properties of a variety of everyday materials.

Early Years Foundation Stage

Understanding of the World


There is one comment

  1. Tom Shrill

    Though wood isn’t inherently water proof, there are ways to make it so. All and all though, this is a fun experiment for kids. I am sure my kids would love to try something like this out.

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