Step 2: Do Your Calculations
Lets start with the simple and work our way to the complex
1. Posts – The posts at the top and the bottom need to be the same height. BOCA and OSHA standards specify that the minimum height of the handrail must be 42”. For simplicity that’s the length we are going to specify
2. Handrail – Calculating the length of the hand rail is a bit more complicated.
First we need to determine the angle.
- To do that we take the distance from post to post. Add the step length plus the length from the post to the step.
Then we determine the height of the steps.
- Add the step height together.
Determine the Angle
- Now here were you might need a calculator. In order to get the angle with the height and the length use the following equation. Divide the Height by the Length. Then do an Inverse Tangent on that number. That number should be the bottom angle of your handrail.
Selecting Angle Fittings
- Now that you have the angle you can determine the type of fitting that you want to use. Kee Klamp fittings offer a number of angled fittings.
- For our project because of the angles we’re going to be using a Type-C50 fittings at the top and at the bottom. They allow you to create a handrail at just about any angle.
C50 - http://www.simplifiedbuilding.com/product_info.php?products_id=196
Now we are ready to determine the length of our handrail pipe.
- First we determine the overall length using the classic formula you learned in geometry a2 + b2 = c2. We just square the height and the length. Add them together. And take the square root of that number. That will give us the overall length.
- Now we’re not done. Because the fittings have some length to them we need to to a little math. There’s a handy chart in the Kee Klamp catalog (and on our website- http://www.simplifiedbuilding.com/hand_rail.php ) which gives us the numbers we need to subtract. There is no figure for the C50 (they do have offsets for other popular angle fittings) so we just figured an 1" on each side.
I threw together a spread sheet to do these calculations.. I left my numbers in it and attached it so that you can see where I'm coming from.
- There are many different types of flanges to mount your handrail. We chose to use a simple Type 62 flange. We then used Tapcon concrete anchors to secure these to cement.
62 Flange - http://www.simplifiedbuilding.com/product_info.php?products_id=270
One more piece:
Because we’re using a Type C50 fitting we’ll need a Type 84 malleable plug. This will finish off the top pipe and make sure no water get’s inside.
84 Malleable Plug - http://www.simplifiedbuilding.com/product_info.php?products_id=336
When installing a handrail make sure that you use Schedule 40 PIPE (not tube or fence post).
When selecting pipe you want to make sure that the steel is galvanized. This will ensure that you handrail will not rust. You might also think about having your pipe powder coated to protect it.
Here are the parts and required tools
We’ve got three pieces of Schedule 40 1-1/2" galvanized steel pipe. This you can get at a local pipe store (note you can't get this at Home Depot)
2 x 42”
1 x 28" (this is particular to our project)
We’ve got the following fittings:
2 Type 62-8 flanges - http://www.simplifiedbuilding.com/product_info.php?products_id=270
2 Type c50-88 swivel fittings - http://www.simplifiedbuilding.com/product_info.php?products_id=196
2 Type 84-7 malleable plug - http://www.simplifiedbuilding.com/product_info.php?products_id=336
For hardware we have:
4 Concrete anchors - ConcreteFastners.com
For Tools we have:
Concrete Drill Bit
Level (not required)
Rubber Mallet (or hammer and cloth)