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Overview of Glazing Tape Types & Methods
Choosing the right glazing tape starts with two questions: do you have a glazing detail (the engineering drawing that specifies the components in the system), and which glazing method are you using? The method determines the tape family; the detail determines the dimensions.
The three primary glazing methods
1. Drop-in glazing
Common in residential windows and doors: an insulated glass unit (IGU) drops into a four-sided glazing pocket, and a pressure cap is applied afterward. This is the most common tape glazing method and provides an excellent seal.
Suitable tapes: BGT crosslinked polyethylene glazing tape; 15# and 25# PVC glazing tapes.
2. Structural glazing
Used in skylights and commercial applications, replacing structural silicone caulk with acrylic foam tape. Benefits include clean sight lines, very rapid cure times, and ease of fabrication — the assembly can move immediately after application instead of waiting hours or days for silicone to cure.
Suitable tapes: SGB, SGG, and SGW acrylic foam structural glazing tapes.
3. Silicone structural glazing
In commercial curtain wall and cladding systems, the tape acts as a spacer while structural silicone caulk provides the primary seal. The approach assures maximum bond strength and gives the system a secondary seal.
Suitable tape: SGT T2040 polyurethane structural glazing tape, single- or double-sided.
Tape material specifications
| Tape | Construction | Key properties |
|---|---|---|
| BGT crosslinked PE | Closed-cell foam, solvent-based acrylic adhesive; black or white; 1/32"–1/8" thick | No curing or edge trimming required; economical drop-in choice |
| 15# / 25# PVC | Closed-cell high-density PVC foam, aqueous acrylic adhesive | Very low compression set; superior recovery through extreme temperature swings |
| SGB / SGG / SGW acrylic foam | Double-coated acrylic foam | Excellent elongation, high tensile and shear strength; immediate movement after application |
| SGT T2040 polyurethane | Open-cell microcellular; single- or double-sided | Breathes while shedding water; single-sided allows repositioning, double-sided adds secondary seal |
Structural glazing tape (acrylic foam and polyurethane)
Structural glazing tape carries load. Unlike a drop-in glazing tape that simply seals a pocket, a structural glazing tape bonds the glass or panel to the frame and holds it there under wind load, thermal movement, and vibration. Two constructions do this work, and they are not interchangeable.
Acrylic foam structural glazing tape. A double-coated, closed-cell acrylic foam core with acrylic adhesive on both faces. The foam core is viscoelastic, so it stretches with differential movement between glass and aluminum and recovers without losing the bond. H-O converts the AFTC SGG (gray), AFTC SGB (black), and AFTC SGW (white) grades in the thicknesses and slit widths your glazing detail calls for, on rolls or as die-cut pieces. Because the bond is immediate, the assembly can move to the next station right after the glass is set. Full bond strength typically develops over about 72 hours as the adhesive wets out, so glaziers should confirm the manufacturer's handling window before shipping units.
Polyurethane structural glazing tape. An open-cell microcellular polyurethane foam, single- or double-sided, that is used with structural silicone rather than instead of it. The SGT T2040 single-sided version is repositionable during setting; the SGT T2040 double-sided version adds a secondary seal behind the silicone. This is the tape most curtain wall detailers mean when they say "spacer tape," covered below.
If you are comparing the two, the question to ask is whether the tape is the structural attachment or the spacer for a silicone bead. Acrylic foam tape is the attachment. Polyurethane tape is the spacer. The full AFTC structural glazing line is on the Coated Acrylic Foam Tape (AFTC) page.
Glazing spacer tape
Glazing spacer tape, also written as structural glazing spacer tape or silicone spacer tape, is the open-cell foam strip installed between the glass and the frame in a silicone structural glazing joint. It does three jobs at once. It sets the joint depth so the structural silicone bead has the bite and thickness the sealant engineer specified. It holds the lite in position while the silicone cures, which can take days. And because the foam is open-cell, it lets moisture and byproducts of cure escape rather than trapping them against the sealant.
Spacer tape is never the structural bond. The silicone is. That is why spacer tape can be single-sided: it needs only enough adhesion to stay put during assembly. Common thicknesses run from 1/8" to 1/2", matched to the silicone bead depth in the detail, in widths sized to the bite. The SGT T2040 polyurethane tape above is the H-O product for this role. When a detail calls for a specific density or a closed-cell variant, send the drawing and we will match it from the polyurethane foam families we convert.
Two compatibility points matter more than anything else on the spec sheet. The spacer tape must be compatible with the structural silicone (most silicone manufacturers publish tested spacer tapes, and untested pairings can stain or soften the sealant), and the tape must not be so soft that the glass sags before cure. If either is in doubt, ask the silicone supplier for a compatibility letter before releasing the detail.
Foam glazing tape: PVC vs. crosslinked polyethylene
Foam glazing tape is the closed-cell tape used in drop-in glazing, where a pressure cap or stop holds the IGU and the tape's job is to cushion the glass, seal the pocket against air and water, and take up manufacturing tolerance. The two foam chemistries H-O converts for this are PVC and crosslinked polyethylene, and each has a case to make.
PVC foam glazing tape is the denser choice. The 15# PVC glazing tape and 25# PVC glazing tape are named for their nominal density in pounds per cubic foot. Higher density gives very low compression set, so the tape keeps pushing back against the glass through years of hot-cold cycling instead of taking a permanent set and opening a leak path. PVC foam glazing tape is the usual pick for windows in demanding climates, for thicker glazing pockets, and wherever a specifier has called out AAMA 810.1 expanded cellular glazing tape performance.
Crosslinked polyethylene (XLPE) foam glazing tape is the economical choice for high-volume residential glazing. BGT polyethylene glazing tape comes in 1/32", 1/16", and 1/8" thicknesses with a solvent-based acrylic adhesive, in black or white. It needs no cure and no edge trimming, and it runs cleanly on automated tape applicators. The tradeoff is compression set: XLPE recovers less than high-density PVC after long compression, so it belongs in pockets with tighter tolerance and milder service.
Both families arrive as rolls slit to the pocket width, or as kiss-cut pieces on a liner when the frame geometry calls for corners and returns. Both can be laminated to a second material when the detail wants a barrier film or a heavier adhesive on one face. For a fuller treatment of setting blocks, weatherstrip, and the rest of the window and door bill of materials, see the Window & Door Sealing Components page and the Fenestration industry hub.
Application notes
Choosing among them
BGT offers economy in drop-in glazing; 15# PVC provides thickness and durability; SGB / SGG / SGW enable immediate post-glazing movement; SGT T2040 serves silicone structural applications requiring spacer functionality. If your glazing detail is still in flux, send it over — our team can recommend the right tape for the system.
Ready to spec a glazing tape?
Send your glazing detail and the glazing method. Engineering reviews every RFQ, recommends the tape family, and slits rolls to the widths your detail calls for.
Samples typically ship in 3 to 5 business days for common die-cut configurations; standard production runs about two weeks; special orders are quoted to the job.
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Frequently asked questions
What is a glazing detail and do I need one?
A glazing detail is the engineering drawing specifying the components in the glazing system. It determines tape dimensions; if yours is still in flux, H-O can recommend a tape from the glazing method and system geometry.
Can acrylic foam tape really replace structural silicone?
In structural glazing applications, yes — SGB/SGG/SGW acrylic foam tapes withstand the stresses of glazing and cladding, with clean sight lines and immediate movement after application instead of multi-day silicone cure.
What is the difference between structural glazing tape and glazing spacer tape?
Structural glazing tape (acrylic foam such as AFTC SGG, SGB, and SGW) is the structural attachment: it bonds the glass to the frame and carries the load. Glazing spacer tape (open-cell polyurethane such as SGT T2040) sets the bite for a structural silicone bead and holds the glass while the silicone cures; the silicone, not the tape, is the structural bond.
Which foam glazing tape should I use, PVC or polyethylene?
Choose 15# or 25# PVC foam glazing tape when low compression set and long-term recovery matter, such as thicker pockets, harsh climates, or an AAMA 810.1 callout. Choose BGT crosslinked polyethylene glazing tape when the pocket tolerance is tight, service is mild, and cost and applicator speed drive the decision.
Can H-O slit glazing tape to a custom width or supply it as die-cut pieces?
Yes. Every glazing tape family here is converted to order: slit rolls to your pocket width, kiss-cut pieces on a liner for corners and returns, or laminated to a film or second adhesive when the detail requires it. Send the glazing detail and we will quote the format that fits your line.
Request a quote for your glazing tape
Send H-O your material role and geometry—engineering reviews every RFQ, recommends a family per material, and converts samples on your geometry.