• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
Menu
  • Science Experiments For Kids
  • Science Fair Projects
  • Science Facts
  • Science Questions
  • About
    • Emma Vanstone
    • About Science Sparks
Science Experiments for Kids
Menu
  • STEM Challenges
    • STEM Challenges
    • FREE STEM Challenge Templates
  • Early Years Science
    • Preschool Science
    • Sensory and Messy Play
    • Understanding of the World
    • Pirate Science Experiments
  • Primary Science
    • Baking Soda Experiments
    • Candy Experiments
    • Biology
    • Climate Change for Kids
    • Coding for Kids
    • Chemistry
    • Electricity for Kids
    • Magic Science Experiments
    • Harry Potter Experiments
    • Human Body Science
    • Air Pressure Experiments
    • Life Cycles
    • LEGO Science Experiments
    • Kitchen Science
    • Famous Scientists
    • Forces and Motion
    • Science Sparks Snippets
    • Key Stage 1 Science
      • Animals
      • Everyday Materials
      • Plants
      • Coding Activities
      • Humans and Health
      • Fine Motor skills
      • Science and Literacy
    • Key Stage 2 Science
      • Animals, Including Humans
      • Electricity
      • Light
      • Plants
      • Materials and their Properties
  • Holiday Science
    • Christmas Science
    • Halloween Science
    • Easter Science
  • Storybook Themed Science Experiments
  • Wonderful Women in STEM
  • FREE Science Resources
menu icon
go to homepage
search icon
Homepage link
  • FREE Experiments
  • Science for Kids
    • Kitchen Science
    • Climate Change
    • Egg Experiments
    • Fairy Tale Science
    • Edible Science
    • Human Health
    • Chemistry
    • Inspirational Women
    • Forces and Motion
  • Science Fair Projects
  • STEM Challenges
  • Science Sparks Books
  • Contact Science Sparks
  • Science Resources for Home and School
    • Email
    • Facebook
    • Instagram
    • Twitter
    • YouTube
  • ×
    Home » Early Years Science » Waterproof Roof STEM Challenge

    Waterproof Roof STEM Challenge

    Modified: Feb 22, 2024 · Published: May 22, 2014 by Emma Vanstone · This post may contain affiliate links · 3 Comments

    This waterproof roof STEM challenge is a simple but fun activity that even very young children will enjoy. My 3,5 and 7-year-old loved it, especially when it came to making it ‘rain’.

    LEGO waterproofing experiment

    Before starting, we spent a few minutes talking about what we expected to happen and how we could make the investigation a fair test.

    We decided that the roof tiles would be the most waterproof, followed by the sticks and then grass. However, we did discuss that it would depend on how many sticks and how much grass we used and that it would be hard to make the comparison fair.

    LEGO HOUSE for a STEM challenge

    Materials

    LEGO House

    Roof materials – we used LEGO tiles, sticks and grass

    Water sprayer

    Method

    Place your chosen roof onto the house and spray water on top. We used a set number of sprays to make it a fair test.

    Record any moisture inside the house.

    wet roof of a small LEGO house for a science experiment

    Results

    As predicted, the roof tiles kept the inside of the house dry, the grass let some water in, and the sticks were also waterproof.

    lego house

    Improvements

    To improve the accuracy of this investigation, we decided what we should have done was use grass, sticks, and tiles up to a certain height above the top of the house and keep that constant for all conditions.

    Recording the amount of moisture inside the house was difficult. Perhaps if we’d placed paper inside and changed it for each condition, we could have compared the dampness of each piece.

    Can you think of any other improvements?

    More LEGO science activities

    Try one of my 15 Fun ideas for Science with LEGO.

    Which is the most waterproof roof

    Last Updated on February 22, 2024 by Emma Vanstone

    « Learning about Symmetry
    6 Easy Air Pressure Experiments for Kids »

    Safety Notice

    Science Sparks ( Wild Sparks Enterprises Ltd ) are not liable for the actions of activity of any person who uses the information in this resource or in any of the suggested further resources. Science Sparks assume no liability with regard to injuries or damage to property that may occur as a result of using the information and carrying out the practical activities contained in this resource or in any of the suggested further resources.

    These activities are designed to be carried out by children working with a parent, guardian or other appropriate adult. The adult involved is fully responsible for ensuring that the activities are carried out safely.

    Reader Interactions

    Comments

    1. Almost Unschoolers

      May 27, 2014 at 2:41 am

      I like the way this got you thinking not only about how to test the different materials, but how to create a fair and accurate test – great problem solving activity!

      Reply
    2. Natalie PlanetSmartyPants

      June 02, 2014 at 2:43 am

      Great idea for an experiment. I was thinking of making a “water level gauge” inside to measure moisture and putting a paper towel square inside to see if it gets wet at all. Thanks for sharing with After School Link Up.

      Reply
    3. Jessica

      April 06, 2015 at 6:47 pm

      I might use water tinted with a little bit of blue food coloring and put a paper towel inside the house. The blue water would show up much better on the paper towel and the results of each type of roof could be compared.

      Reply

    Leave a Reply Cancel reply

    Your email address will not be published. Required fields are marked *

    Primary Sidebar

    • Email
    • Facebook
    • Instagram
    • Twitter
    • YouTube

    What are you looking for?

    Fill your inbox with science

    Newsletter

    Signup for weekly science in your inbox

    You can unsubscribe anytime. For more details, review our Privacy Policy.

    Thank you!

    You have successfully joined our subscriber list.

    Science Sparks Books
    Around the World in 50 Experiments

    Footer

    ↑ back to top

    Science Sparks - FREE science experiments for kids

    Newsletter

    • Sign Up! for emails and updates

    Contact

    • Contact
    • Privacy Policy
    • Services
    • Media Kit
    • FAQ

    As an Amazon Associate, I earn from qualifying purchases.

    Copyright © 2025 Science Sparks - Wild Sparks Enterprises Ltd