Reference
Glass options and ratings
what the choices actually change
For a South Florida house the glass decision comes down to four questions. Does it have to be impact rated, how clear do you want it, how much heat should it stop, and how private does it need to be. Everything below answers one of those.
Florida license
SCC131154568
Counties served
Martin, Palm Beach, Broward, Miami-Dade
Residential estimates
Same day
Page type
Reference, not a sales pitch
Build
What the glass is made of
This is the first fork and it decides most of the rest. Everything else, tint, coating and etching, gets applied to one of these.
Monolithic tempered
One ply, heat treated so it is stronger and so it breaks into small blunt pieces instead of shards. This is shower glass, railing glass and partition glass.
Laminated
Two plies bonded to a plastic interlayer. When it breaks the pieces stay stuck to the interlayer. That is the whole principle impact glazing is built on: the glass can break and still stay in the frame.
Insulated
Two lites separated by a sealed cavity, with a spacer around the edge holding them apart. The cavity is what slows heat transfer, and the seal around that spacer is what fails when a unit fogs.
And then there is the one you probably want
Laminated insulated is both at once, and it is what most impact windows in Florida actually are: an outer laminated lite that carries the impact requirement, a sealed cavity, and an inner lite. You are not choosing between the two above. You are usually buying both.
Reference
The four builds, side by side
Kept as a table because this is the part people come back to check.
Monolithic tempered
One ply, heat treated so it is stronger and so it breaks into small blunt pieces instead of shards. This is shower glass, railing glass and partition glass.
Laminated
Two plies bonded to a plastic interlayer. When it breaks, the pieces stay stuck to the interlayer. That is the whole principle impact glazing is built on: the glass can break and still stay in the frame.
Insulated
Two lites separated by a sealed cavity with a spacer around the edge. The cavity is what slows heat transfer. This is the unit that fogs if the seal ever fails.
Laminated insulated
Both at once, and what most impact windows in Florida actually are: an outer laminated lite for the impact requirement, a cavity, and an inner lite.
Acid etched glass: clear above, satin below. The etch is in the surface, not a film, so it does not peel and it cannot be scraped off.
Clarity and color
The five finishes we actually stock and order
These are the options on our own product pages, not a manufacturer’s full catalog.
Clear
Standard float glass. Look at the polished edge and you will see green. On a large pane, and on anything stacked or thick, that green reads.
Low iron
The iron that causes the green is removed. Almost colorless, and worth it wherever the edge is exposed or the glass is thick. Standard on high end shower and railing work.
Tinted
Bronze or gray in the glass body. Cuts glare and visible light, and changes the color of the light in the room. A design decision as much as a performance one.
Acid etched
The surface is etched to a soft even translucence. Light passes, detail does not. Used for privacy without losing the daylight.
Acid etched low iron
The same etch on low iron glass, so the finish stays neutral white instead of picking up a green cast.
Low-E coating
A microscopically thin metallic coating that reflects heat. It is designed to help reduce heat transfer compared with older uncoated single pane glass. How much depends on your orientation, your shading and the rest of your envelope.
In practice
What the build choice looks like once it is in
The spec sheet stops mattering the day it is installed. What you live with after that is the light, the view and how quiet the room is, and those come from the glass build as much as from the frame around it.
Ratings
The numbers that show up on your permit
You do not need to memorize these. You do need to know that they exist, because the approval has to cover your opening before anyone can pull a permit for it.
Large Missile Impact
The assembly is fired at with a nine pound piece of lumber and then cycled under pressure. Tested to ASTM E1886 and ASTM E1996, and in the High Velocity Hurricane Zone to TAS 201, 202 and 203.
Design Pressure, DP
How much positive and negative pressure the assembly is rated to take. Your engineer calculates what the wall needs and the product has to meet or beat it.
Miami-Dade Notice of Acceptance
The approval used in the High Velocity Hurricane Zone, which is Miami-Dade and Broward. Each NOA covers specific sizes and configurations.
Florida Product Approval
The statewide route, accepted in Martin and Palm Beach. Same idea, different administering body.
U-factor and SHGC
The two thermal numbers on the NFRC label. U-factor is how much heat moves through. SHGC is how much solar heat gets in. Lower is less, for both.
Safety glazing
The code requires tempered or laminated glass in specific locations: doors, next to doors, near the floor, around tubs and pools. It is not optional and it is not a upgrade.
In practice
What this means for four common jobs
Replacing windows on the coast
Laminated insulated with a Low-E coating, impact rated, with the approval that matches your county. This is the default and there is not much to decide beyond tint and frame color.
A frameless shower
Tempered, and low iron if the walls are white or pale stone. On clear glass the green edge is visible against white and people notice it after the fact.
A glass railing
Tempered or laminated depending on whether there is a top cap, and low iron when the run is long and you see edge after edge.
An interior partition
Tempered, and acid etched where you want light without a fishbowl. No impact requirement, because it is not in the building envelope.
Not sure
Ask before you order
Glass is easy to get wrong once and expensive to get wrong twice. Tell us the room, the orientation and what is bothering you about the light, and we will tell you what we would specify.
- (561) 584-8485 · Monday to Friday, 8am to 5pm
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- 7830 Byron Dr Ste 4, West Palm Beach, FL 33404
- Florida certified specialty contractor SCC131154568