Nosefish Shower Gantry


This page will help you determine the lengths of the straight pieces of PVC in the gantry (the top) of the shower. Don't glue anything together yet! This page will just let you determine the sizes of the pieces.

First, lets name the different parts.

  • There are four corners (you already built them -- you made 6).
  • There are two sides which in the picture are the short sides of the rectangle which makes the bottom of the gantry (not the part that rises up and holds the shower bag).
  • The other two sides of the rectangle are actually composed of three sections each that are connected with tee fittings. I call them the riser support sides.
  • The riser support sides are composed of two corners, two short stubs, two tees and a middle piece.
  • The tees also connect to the risers.
  • The risers connect to two more corners between which is the horizontal shower bar.
  • The gantry is held aloft by four vertical sides made from 1" PVC (not shown in the diagram.) These are never glued. You need the vertical sides to slip-fit but not glued so they can be disassembled for transport.

I cut the stubs an arbitrary 6" long.

I cut the short sides so that when the corners were placed over the corners of the shower base the vertical risers (which plug into the 1" slip fitting in the corner) fit right into the inside corners of the shower base. About 5/8" of the straight PVC fits into slip fittings. You can press the corners onto the side pieces without glueig them together to check their width.

The long sides are composed of three pieces. Two of them are already cut at 6". So, the remaining piece needs to fit between the two tees. When you put the remaining piece together with the two tees, two 6" pieces and the corners, the corners should exactly align over the corners of the base, the same way the short sides did. Push the pieces together (without glue!) and test fit the length. You can put the rest of the pieces together (minus the middle length) and measure the distance between the tee joints, add about 1.25 to 1.5 inches to that length and cut the middle piece. Then press them together and test them out. If needed you can trim some off.

To detmine the length of the risers you need to do a little math, using the pythagorean theorem.

This is an abstract view of the gantry seen from the side. The vertical line is imaginary. The two diagonal sides are the risers. The horizontal line is the short side.

The entire width of the shower (the short side) is called "Shower side" in the above diagram. Measure the length to the center of the corner piece, not the edge. That is, to an imaginary point at the intersection of the three axes of the corner piece. Half this length is the width of the base of a triangle we'll call a riser triangle. There are two riser triangles in the above diagram separated by an imaginary line in the middle of the diagram.

Since the two risers will meet at a 90 degree angle at the top, the two angles at the base of the riser triangle will be 45 degree angles. The base of the riser triangle will be equal to its height.

Call the base (and height) L. The length of the entire riser (including extra length to reach the imaginary point at the intersection of the 3 axes of the corners and the tees) is the square root of 2 x L x L. Use a calculator. If L was 14" then the entire riser height would be the square root of 2 x 14 x 14, or approximately 19.8 inches.

But, the length you need to cut is somewhat less than this. Your riser only extends about 5/8" into the tee and corner slip fittings. There is about 1" beyond that on each end to get to the imaginary center point. So, you will need to cut the riser about 2" shorter than what you calculated, so that when you assemble the pieces they work out to the right length.

The shower bar is shorter than the middle pieces. I put the whole gantry together (without gluing it!) and measured the distance between the 1" slip fittings that would hold the shower bar. Then I added about 1.5 inches. I cut that length, which seemed to be just a little too long. So I cut of a little and got it to fit.

The four sides of the shower can be any length you want. I made mine 7 feet.