PVB or SGP interlayer — which one belongs in your curtain wall specification? Both produce laminated safety glass, but they behave differently under load, heat and long-term weathering, and the wrong choice on a high-rise or coastal project shows up years later as yellowing, delamination or a structural glazing failure that was never actually tested for. Here is how the two compare for commercial curtain wall and glazing packages sourced from China.
| Property | PVB (Polyvinyl Butyral) | SGP (SentryGlas / Ionoplast) |
|---|---|---|
| Stiffness | Softer, more flexible interlayer | Roughly 5x stiffer — glass panels can be thinner for the same structural performance |
| Post-breakage strength | Holds broken glass together but sags under continued load | Retains structural integrity after breakage — used in structural glazing and overhead applications |
| Edge stability / yellowing | Can discolor and delaminate at exposed edges over years, especially in hot-humid climates | Higher edge stability, better long-term clarity in harsh climates |
| Typical cost | Lower material cost | Higher material cost, justified where structural or safety performance is required |
| Typical commercial use | Standard laminated safety glass, general curtain wall, balustrades | Structural glazing, point-supported facades, hurricane/blast-resistant glazing, overhead skylights |
When Does PVB Make Sense?
For standard curtain wall glazing where the glass is fully framed and supported on all edges, and the climate is not pushing extreme heat or humidity at the glass edge, PVB laminated glass is the conventional, cost-effective choice. It is what most commercial buildings specify by default.
When Should a Project Specify SGP Instead?
SGP earns its higher cost in a few specific situations: structural glazing where the glass itself carries load with minimal metal support, point-fixed facade systems, hurricane and impact-resistant glazing in coastal markets, overhead glazing (skylights, canopies) where post-breakage retention matters for safety, and any application where long-term edge clarity in a hot, humid or coastal climate is a real durability concern. If your project is in a hurricane zone or your architect has specified structural glazing, confirm with them whether PVB actually meets the design intent before a factory quotes it as a cost-saving substitution.
Sourcing laminated curtain wall glass for a commercial project?
FBM Sourcing works with project owners, developers, main contractors and FF&E contractors on hotel, apartment, school, office and other commercial building projects. Send us your BOQ, drawings or product list — we’ll come back with a sourcing plan and budget estimate.
How to Specify This Correctly When Sourcing from China
- State the interlayer type explicitly in the RFQ — “laminated glass” alone is not a specification; factories will quote PVB by default because it is cheaper, unless SGP is named.
- Match interlayer thickness to the structural calculation — this should come from your structural engineer or facade consultant, not be left to the factory’s standard offering.
- Request test certificates matching the actual interlayer and glass thickness combination being supplied, not a generic manufacturer brochure.
- Inspect for edge seal quality at the factory — this is where both PVB and SGP laminated units fail first if production quality is inconsistent.
See our related guide on Chinese curtain wall and architectural glass manufacturers for factory options.
Get a China Procurement Quote for Your Glazing Package
Send us your glazing schedule with interlayer type, thickness and destination market, and we will come back with manufacturer options, certification mapping and project pricing. Start at our building materials & FF&E procurement page.
