How to Make a Bridge Out of Straws

••• chris hansen/Demand Media

Engineers have worked over the years to develop better, stronger bridges that can hold up enormous amounts of weight. Students can learn about bridges, and differences in strength among the types of bridges, by building their own out of straws. Whether the bridge is for an experiment or a model, straw bridges work well when built properly and hold up against a relatively heavy weight.

    ••• chris hansen/Demand Media

    Cut six straws in half to create twelve smaller pieces. You may need more if you want to create a long bridge. Lay out three pieces to form a triangle and tape them together at the corners with masking tape.

    If the tape doesn't hold the triangles, roll up a small ball of clay and insert the straw pieces. Apply one at each corner and add tape if necessary to hold the straws to the clay. Certain projects may ask you to only use straws and tape, in which case you'll need to add extra tape to ensure your straws stay in place.

    ••• chris hansen/Demand Media

    Repeat until you have four triangles. Cut up six more straws and create four additional triangles for a total of eight. Check that the triangles are all the same size. Lay four triangles out side by side with only the bottom corners touching and tape the corners together. Repeat for the other four triangles to create two sets of four.

    ••• chris hansen/Demand Media

    Place a straw along the bottom of the four triangles and secure it by placing a piece of tape around the straw and the center of each triangle. Repeat for the other set of four triangles. Tape together two straws if one is not long enough and trim away the extra length on the ends.

    ••• chris hansen/Demand Media

    Place a straw along the top of the four triangles and tape around the straw and the point of each triangle. Repeat for the second set of four triangles and trim off any excess straw sticking out.

    ••• chris hansen/Demand Media

    Ask a friend to hold the two sets of triangles, which are now the sides of your bridge, upright and approximately 2 to 3 inches apart running parallel to each other. Extend pieces of straw underneath the top corner of each of the four triangles to slide under the tops of the triangles on the other side. Tape the straw pieces in place. Repeat with the corners at the bottom of the triangles.

    ••• chris hansen/Demand Media

    Place your bridge on a sturdy surface. If it seems unstable or does not seem strong enough, connect a small piece of straw from the top corner of each triangle down to the center of the bottom straw forming that triangle. Make sure to connect it to the long straws running above and below the triangles. This provides extra support for your bridge.

    Things You'll Need

    • Scissors
    • Straws
    • Masking tape
    • Clay or sticky tack


    • When designing your own straw bridge remember that triangles are the strongest shape you can use, according to online resource Technology Student, while squares are the weakest.

Related Articles

How to Build a Spaghetti & Marshmallow Tower
How to Build an Elbow Joint Model
How to Build a Covered Wagon Model for Kids
How to Construct a Dodecahedron With Straws
How to Use a 30-60-90 Drafting Triangle
How Can I Make a Watch Tower for a School Project?
How to Make a Tower Out of One Piece of Paper
How to Make a Strong Bridge Out of Popsicle Sticks
How to Make a DNA Model Out of Beads & Straws
How to Build a Stable Tower Out of Straws
How to Build a Strong & Stable Structure Project for...
How to Make a 3D Hexagon
How To Calculate The Area of an Irregular Shape
Geometric Concepts Found in Bridges
How to Split a Triangle Into Fourths
How to Build an Egg Catapult
How to Calculate the Square Foot of an Irregular Polygon
How to Build a Knee School Project
How to Find the Missing Slope of a Trapezoid
How to Make Cardboard Machines

Dont Go!

We Have More Great Sciencing Articles!