Which Roofing Material Keeps Houses Coolest?

Troy C.
4th Grade, Imperial Estates Elementary, Titusville Florida
Teacher: Barbara Glinski

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Hypothesis:
I think that a roof made of PVC will keep a house coolest because it is white colored and reflective.
(Professor Sunny's note: The roofing materials that Troy tested were PVC, pebbles, tile and shingles)

Conclusion:
I reject my hypothesis. I hypothesized that PVC keeps houses coolest. I reject my hypothesis because pebbles worked best, not PVC. People might use my project when they buy roofs for their houses. They might use it to decide which roof to buy. Also, if I were to do my project again, I would do it in the summer.
View close-up of Troy's graphs