Science Buddies: "Ask an Expert"

Topic Question: Do grass roofs insulate as well as the common roof?

I need to know how I should carry out my experiment? Should I build a set of identicle "mini" houses and add the corrosponding roof type? Any suggestions or ideas? Please help:D
Thanks for your attention.

that sounds like a very interesting project!
Your idea sounds very good....making small replica houses and using the two different types of roofs. Just make sure that both types of roofing are exposed to the same conditions (sun light, moisture, ect.)
in addition, you can also look at comparing the cost and lifespan of both types of roofing
also, here is a related project idea: https://www.sciencebuddies.org/science- ... p016.shtml

let me know if you have any more questions

good luck,
scienceexpert123

Hi,

I've moved your post to the physical sciences forum because I think that they will better be able to help you.

Good luck!

From an Engineer's perspective, you have a classic "cost function" or "evaluation basis" problem with no clear obvious definition of what the "cost function" should be.

To illustrate this point, what if the question was "Are apples better than oranges?". Well, they are both fruits (in your case both roofs). From that point on though, there are more differences than simularities. If you define the "cost function" to be which has more vitamin "C", the answer is likely to be the oranges. If you define the "cost function" to be which has the least acidity, the likely answer will be apples.

Are you talking about a "dried (dead) grass thatch roof" or are you talking about a "sod (live grass) roof"?

If you are talking about sod, then the roof needs another material to be used as a moisture barrier and your "cost function" choice might end up making the decision based on the specific moisture barrier you tested with.

If you are talking about a "thatch roof", then type of grass, experience of the people constructing it, weight, and lots of other factors could easily determine the outcome.

Questions that attempt to rank (based on some cost function) different materials or designs are highly dependent on the choice of the judgement criterion (choice of cost function).

In the case of roofs, insulation properties are not the ONLY properties of interest and if your cost function only judges the heat transfer properties, then you could end up with a very good insulating material but be wet when it rains.