Interlayer Thickness for Wind

The plastic layer between glass panes is what keeps hurricane windows together after impact. Think of it like the filling in a sandwich - thicker filling holds the bread together better. See how different thicknesses protect your home.

0.060" PVB Hurricane rated
0.090" SGP Premium strength
Laminated Glass Cross-Section
Glass (outer)
0.030" PVB
Glass (inner)
0.030" Thickness
1x Relative Strength
Standard Rating

Interlayer Options

Compare PVB and SGP interlayers for hurricane window applications.

Standard Glass

PVB 0.030"

0.76mm
  • +Basic lamination
  • +Sound reduction
  • +UV protection
  • -Not impact rated
  • -Not HVHZ approved
Best for
Interior glass, skylights (non-HVHZ)
Hurricane Glass

PVB 0.060"

1.52mm
  • +Large missile rated
  • +HVHZ approved
  • +Good tear resistance
  • +Cost effective
  • -Less rigid than SGP
Best for
Standard impact windows, Palm Beach HVHZ
Premium Glass

SGP 0.090"

2.28mm
  • +5x stiffer than PVB
  • +100x tear resistant
  • +Humidity resistant
  • +Large openings
  • +Maximum protection
Best for
Storefront, large windows, coastal exposure

Frequently Asked Questions

Common questions about interlayer thickness for hurricane windows.

What is the interlayer in laminated hurricane glass?
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The interlayer is the plastic layer sandwiched between two pieces of glass that holds everything together when the glass breaks. It works like the filling in an Oreo cookie - it bonds the two glass pieces together. The most common types are PVB (polyvinyl butyral) and SGP (SentryGlas Plus), with SGP being about 5 times stiffer and 100 times more tear resistant.
What interlayer thickness is required for hurricane windows in Palm Beach County?
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Palm Beach County requires impact-rated glass that passes large missile testing (9 lb 2x4 at 50 fps). Most manufacturers use 0.060 inch PVB or 0.090 inch SGP interlayers for this level of protection. Standard 0.030 inch PVB is typically not thick enough to pass hurricane impact tests in the HVHZ.
Is SGP interlayer better than PVB for hurricanes?
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Yes, SGP (SentryGlas Plus) is stronger than PVB. SGP is 5 times stiffer and resists tearing 100 times better after the glass breaks. This means SGP holds up better during long storms with multiple debris impacts. SGP also performs better in humidity and high temperatures common in Florida.
Can I use thinner interlayer for smaller windows?
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Sometimes, but it depends on the tested assembly. Each window must use a laminated glass assembly that has been tested and approved for the specific wind zone. A smaller window might qualify with thinner glass and interlayer, but the entire unit must have a valid product approval showing it passes the required impact test.

Calculate Your Glass Requirements

Get precise glass and interlayer specifications for your windows. PE-stamped calculations available.

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