When you walk or drive around your neighborhood what do the roofs look like? What if you lived in an area with a different climate, how would that effect the style of roof that you might find. This is an introductory activity to explore the advantages of different roof shapes for different climates or situations.

LEVEL OF DIFFICULTY [1 = Least Difficult : 5 = Most Difficult]

1- Least Difficult

TIME REQUIRED

40 minutes (1 class period)

COST

$5-$10 per class (less than $0.50 per student)

1.3 Identify and describe the safe and proper use of tools and materials (glue, scissors, tape, ruler, paper, toothpicks, straws, spools) to construct simple structures.
2.1 Identify tools and simple machines used for a specific purpose, e.g., ramp, wheel, pulley, lever.

Materials both natural and human-made have specific characteristics which determine how they will be used.
Engineering design requires creative thinking and consideration of a variety of ideas to solve practical problems.

A model is a copy of an object that is too big, too small, or too complicated to study easily. Engineers use models to test and study how well things are built or to test different designs. A load to an engineer is any force that pushes or pulls. For example: the weight of snow pushes down on a building, creating a snow load. A wind load pushes on the sides of a building.

RESOURCES:
http://eetd.lbl.gov/HeatIsland/CoolRoofs - Heat absorption and roof color
http://www.metalroofing.com/prods_manu.cfm - Pictures of Metal Roofs
http://www.heimer.com/information/roof.html - Pictures of Different Roofs
http://www.nsf.gov/od/lpa/events/fow/fowtfkv1n4/htm/start.htm - Good Background and Pictures

3 Shoeboxes or similar container
1 Poster Board
1 newspaper
About 2 cups of flour
A flour sifter or sieve would be a nice tool to have

Cut away one end of the box so that students can view the effects of a snow load. Use poster board to make three different types of roofs, one for each shoe box; curved, A-frame, and flat (see Roof Shapes Worksheet). Using a single piece of masking tape, tape each edge of the roof to the open top of the shoebox. Place newspaper under the testing station to catch any loose flour. You may want to place a cookie sheet under the box so that loose flour can be used in the next test. Obtain flour and containers to hold about 2 cups of flour. A flour sieve would be a nice tool to have available. Gather picture of different types of roof to show the class.

DIRECTIONS:

1. Show the class picture of different styles of roofs, talk with the students about what types of climates these roofs might be found in. What characteristics make a roof, ok for a given climate?
2. Show the class the example roofs that you created, explain to them that the flour will represent snow and have them make predictions as to which roof would be best for a snowy climate?
3. Slowly sprinkle “snow” onto the center of the roof. Keep watching the roof through the open end of the box.
4. Have the students make observations as the snow is applied to the roof.

Caution:
To avoid a flour storm carefully lift the roof and gently tap the bottom so that
the flour falls into the shoe box. Pour the flour from the shoe box into a
container to be used for the next test.

Predict which types of roofs will cave in to snow the easiest? Why?
Does the “snow” pile up or slide off?
Which roofs sag? What does the sagging mean?
Which roofs fall down? Do they fall slowly or all at once?
In addition to snow loads, what other things should we worry about?
Which roof would you choose if you lived in a snowy area? A windy area? Rainy?

National Science Foundation and Time or Kids “Find Out Why?”. [Online] July 16, 2001. http://www.nsf.gov/od/lpa/events/fow/fowtfkv1n4/htm/start.htm

WORKSHEETS:

See Associated Download.

SAMPLE RUBRIC:

See Associated Download.