When constructing the opening for your frameless shower enclosure, one of the most important things you can do is ensure that all of the walls are plumb, level, and square. Custom built heavy glass frameless showers are not very forgiving of an improperly constructed opening.

There are a number of considerations regarding the “squareness” of your opening and the forgiveness of your shower door. Following are the basics of measuring for out of square and for detecting out of plumb. Out of plumb refers to the orientation of walls, step-ups or buttresses along the vertical plane.

Out of Square

For standard inline configurations (such as a fixed swinging door and a stationary panel), measure the opening width at the bottom along the sill and along the approximate top of the unit – not the top of opening, unless your shower will extend to the ceiling. It is important to measure to the 1/16″ and to measure from tile to tile. You cannot perform the measurement step until the opening has been completely tiled.

If your top and bottom width measurements differ by at least 1/4″, you have an out of square condition and the glass may need an edge cut to ensure proper fit. Once you’ve determined that the opening is out of square, the next step is to determine which wall is causing the out of square condition. To do this, hold a level to each wall.

It may be the case that only one wall is not plumb. For example assume the right wall of the opening leans in by at least 1/4″ more at the top than at the bottom. This scenario definitely requires an out of square edge cut so that the glass fits correctly.

In the case where neither wall is plumb, the outage of each wall must be considered separately. If for example, both walls are out of square by only 1/8″ (and the total outage is 1/4″), then there will be enough play on both sides of the opening and an out of square cut can be avoided.

Bowed Walls

Bowed walls present an especially tricky challenge. If you have a wall that bows out at some point other than at the top or the bottom of the opening, then you may have a problem. Technically if the bow is less than 1/8″ and is not on the hinge side of the door, you should be able to bend the channel into place and the glass should have enough room to maneuver. Anything larger than 1/8″ however, and you’ll need to modify your opening.

It’s also possible that your wall could bow in. If your opening is for just a single door, it’s no problem. However, if your opening is for a door and panel and the bow is not on the hinge side of the door and the bow is less than 1/8″ then you may need to apply some extra silicone to close the gap behind the channel. If the gap is greater than a 1/8″, you may need to modify your opening.

If your wall bows in or out on the hinge side of your door, consider the following. If the wall bows in (away from the door), then the only real concern is that you’ll have a gap that is slightly larger than normal. Since most shower heads are located near where the door is hinged (and spray towards the opposite direction), there should be little concern about water escaping.

If the wall bows in toward the door and the bow is greater than 1/8″, you may need to modify your opening. The most important thing is that the hinges line up so that the door swings properly. If the wall bows in the middle, it may end up touching the glass. The gap between a plumb wall and the glass where the door is hinged is 3/16″.

Out of Level

Being out of level is very similar to being out of plumb. As was mentioned previously, being out of plumb by 1/4″ or more requires the glass to be cut at an angle. The same principle applies if your opening is not level along the bottom. If out of level by less than a quarter inch, there should be enough play to secure the glass or not to notice the issue. If your glass does not extend to the ceiling, then it does not matter (in regards to the shower) whether your ceiling or bulkhead is level.

Suppose that your sill is not level by 1/8″ beneath your door. You may have issues with your door sweep providing too much friction on one side and not enough coverage on the other end. You can easily modify the sweep to perfectly fit the out of level opening but cutting the vinyl at an angle with a razor blade.

What It All Means

Hopefully by now you recognize the importance of constructing an opening that is plumb, level, and square. While framed doors have higher tolerances for out of square conditions, frameless showers are custom fit products. To ensure that the glass fits together in your opening with minimal gaps, additional cuts to the glass are required to compensate for any angles in the opening. These additional cuts equate to additional costs.

It is equally important that you precisely measure your opening when ordering a frameless shower door. It is critical that you provide information regarding the plumbness, degree of level, and degree of bowing of the walls comprising your opening. If your measurements are off, the fabricated glass will not fit correctly.

Source by Michael J Schmitz