Glass Thickness &Type Advisor
The right thickness and treatment for the span you actually have.
- Recommended thickness
- Tempered vs laminated call
- Deflection and weight check
Recommended specification
3/8 inch fully tempered
Three-eighths is the standard for a hinged frameless door up to about 32 inches. It is rigid enough not to flex and light enough for normal hinges.
Thickness
3/8 in
Treatment
Fully tempered
Weight per sq ft
4.87 lb
This panel
68 lb
14.0 sq ft
Code requirement
Shower glazing is a hazardous location under IRC R308.4.5. Tempered is mandatory and must carry a permanent etch mark.When to go thicker or thinner
3/8 inch
Your specDoors under 30 inches with standard hinges
1/2 inch
Wide doors, heavy hardware, or where the client wants the substantial feel
| Application | Frameless shower door |
| Door width | 28" |
| Support condition | Hinged on a wall or panel |
| Occupancy | Private residence |
| Thickness | 3/8 inch |
| Treatment | Fully tempered |
| Panel weight at 28" x 72" | 68 lb |
These recommendations reflect standard industry practice and the model code language adopted across DC, Maryland and Virginia. Structural glass, overhead glazing and anything carrying a live load should be confirmed by a licensed design professional before fabrication.
Next step
Get this piece fabricated
Send the spec and we quote the glass, the edgework and the install. We will flag anything the code makes us change.
Spec
3/8 tempered
Frameless shower door — 3/8 inch fully tempered
- Application
- Frameless shower door
- Door width
- 28"
- Support
- Hinged on a wall or panel
- Recommended thickness
- 3/8 inch
- Treatment
- Fully tempered
- Panel weight
- 68 lb at 28" x 72"
- Code
- Shower glazing is a hazardous location under IRC R308.4.5. Tempered is mandatory and must carry a permanent etch mark.
Text it to us
Opens your messages app, already written
Email it to us
Opens your mail app with the full spec
Call and read it out
(703) 470-7867 · 24/7 Emergency Service
Thickness controls stiffness. Treatment controls safety.
These are two separate decisions and conflating them is the most common mistake in glass specification. Thickness answers how much the panel flexes and how much load it carries. Treatment answers what happens the moment it breaks. A half inch annealed lite in a door is more dangerous than a quarter inch tempered lite, even though it is twice as thick and considerably stronger.
Deflection is the reason thickness rules feel so aggressive. Sag scales with the cube of the span, so a shelf that doubles in width sags roughly eight times as much at the same thickness. Glass is extraordinarily strong in compression and it very rarely breaks from ordinary loading — it looks wrong long before it fails, and looking wrong is what people actually complain about.
Decide it before you order
Tempered glass cannot be cut, drilled or ground after it is made. Every dimension, every hinge cutout and every hardware hole has to be final before it enters the furnace. That is why we template rather than work from drawings on anything with hardware, and why a wall that is a quarter inch out of plumb is a conversation to have before fabrication rather than after.
Questions people ask
Because deflection scales with the cube of the span. Doubling a shelf width increases the sag roughly eightfold at the same thickness. That is why a 24 inch shelf is comfortable in 3/8 inch and a 48 inch shelf in the same glass looks like it is about to give way even though it is nowhere near breaking.
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