Dr. Bill Whitmire, Mathematics Educator and House
Builder
More Career Connections
Part of my life is
teaching kids and working with math teachers, solving
math problems and working with technology. That is good.
But I also really like pounding nails, sawing wood,
and trying to figure out the best way to solve a problem.
That's what building stuff is: a lot of thinking to
go along with the physical activity.
A
construction project includes quite a bit of mathematics.
It starts with figuring out how much of the materials
you will need. Materials are a large chunk of the cost
of a building. This includes the cement for the footings,
the lumber( including studs, joists, beams, and sheeting),
as well as nails, flashing, roofing, and insulation.
You don't want a lot of waste, and you also want the
materials you need to be there when you need them. This
is one place where accuracy counts. This is a great
opportunity to use a spreadsheet and your head!
When
you start building, you have to be able to read the
blueprints and figure out how (and where) to pour the
foundation. You want things to be square and level.
If you get off here, you make a lot of extra work for
yourself later. I use 345 triangles to make sure my
angles are square (right angles) and the lines are parallel.
You also have to think about the slope of the land and
how you are going to deal with water drainage. Water
runs down hill, and you don't want your house at the
bottom of a lake.
When
it comes to framing the house, you need to take a lot
of measurements. You want the walls to be plumb (straight
up and down) and square. You also have to build in the
rough openings for the windows and doors. Mathematics
also comes into play when you build stairs. You want
the rise and run (or slope) to be right so that the
stairs come out perfect! No one likes to walk on stairs
where one step is different than the rest. It just isn't
right. So you have to do the math to make your stairs
perfect.
Mathematically,
one of the hardest things to do on a house is to cut
rafters. Roofs need a certain pitch, or angle, so water
will run off them correctly. Many houses have hip roofs
that are made up of two large trapezoids along the long
sides with triangles on the short sides. You want the
ridges and the valleys to have the same angles. Making
that work out requires some hard thinking and high school
geometry.
Once
you get the walls up and roof on and "dried in," there
is still a lot of work. But this gives you the idea.
You have to use your head and have knowledge of measurement,
geometry, trigonometry, ratios and proportions, along
with some algebra for figuring costs and paying the
crew that help you.
