Window & Door Sealing Components: Glazing Tape, Setting Blocks, Weatherstrip Gaskets & Weep Baffles

At the glazed unit itself there are three material problems. The sash-to-IGU primary seal uses crosslinked PE glazing tape (BGT) for shallow drop-in pockets or PVC foam glazing tape for deeper pockets and acoustic IGUs; setting blocks are dense solid silicone in the 80–90 Shore A band per ASTM C864 Option I; weatherstrip and mitered-corner gaskets are closed-cell EPDM foam (RE-series) or solid EPDM sheet (553/563); and SDL grilles and hardware cushion pads use double-coated XLPE or coated acrylic foam tape.

Frame-internal parts — chimney blocks, weep baffles, cavity fill, sill pads, shims — are specified on Residential Window & Door Components, and door perimeter seals on Commercial Doors & Entrances. All are die-cut to drawing; properties are per the TDS on file. [4]

NAFS-2022 is the fifth edition of the North American Fenestration Standard, formally AAMA/WDMA/CSA 101/I.S.2/A440-22, published jointly through FGIA, WDMA, and CSA. It assigns window and door products to performance classes, R, LC, CW, and AW, each with a Design Pressure rating and test gateways: air leakage per ASTM E283, water penetration per ASTM E331/E547, and structural performance per ASTM E330.

The class decides how hard the tests press on the weatherstrip line, the weep system, and the glazing seal, so the same geometry can need different material grades at different classes. Put the class and PG target on the RFQ so the converted components are matched to the gates they must pass. [1]

A glazing tape is a pre-cut, PSA-faced foam tape that beds the insulating glass unit to the sash or frame, replacing wet glazing compounds with a dry bond the line can handle immediately, no cure window, no squeeze-out cleanup, and assemblies can move straight down the line. Crosslinked PE (BGT) is the drop-in default for shallow residential pockets; closed-cell PVC foam steps up for deeper pockets, heavier commercial frames, and acoustic IGUs.

Tape glazing suits factory assembly; field re-glazing and structural silicone applications stay with wet systems. Foam properties are per ASTM D3575 (XLPE) and D1667 (PVC) on the TDS. [9]

Work from the section detail, not the catalog. Three numbers decide it: the pocket depth, the intended glazing bite, and the IGU thickness with its edge clearance. The tape has to compress enough to wet out the pocket corners at the closure force the sash actually applies, and still leave the IGU seated behind the bead rather than proud of it.

BGT crosslinked PE runs in three thickness classes (1008 / 1016 / 1032 per the TDS designations) and PVC foam glazing tape in two density classes; thickness is reported per ASTM D3652 on the TDS on file. Send the section detail with the RFQ and H-O engineering reconciles the class against the pocket during quote review rather than after the first air test. [9]

FGIA/AAMA 813 is the voluntary specification covering the tape used to attach simulated divided lite muntin bars to glass, and it is the document a muntin tape is normally referenced against. Two families do the work: H-O Mount double-coated XLPE for standard residential grille duty, and the coated acrylic foam tape families where the bar is heavier, the exposure is harsher, or the glass face is coated.

Materials are commonly evaluated against FGIA/AAMA 813; the adhesion and peel values are per the vendor TDS on file, and H-O supplies the converted tape rather than certifying the finished lite. [8]

Moving up the R, LC, CW, AW ladder raises the Design Pressure the assembly is tested to, and that changes two things about the components. The structural gateway (ASTM E330) presses harder on the glazing pocket, so tape thickness class and pocket bite get re-examined.

The water gateway (ASTM E331 / E547) presses harder on the weatherstrip line, which is typically where the material grade actually changes: the softer RE-series EPDM foam classes at R and LC, stepping to the firmer RE grades at CW and AW where closing force and UV and ozone headroom over the service life govern.

Setting-block hardness does not move with class — the ASTM C864 Option I band applies throughout. Put the class and PG target on the RFQ so the grades are matched to the gates rather than to the catalog line. [1] [2]

ASTM C864 Option I covers dense elastomeric setting blocks — silicone, EPDM, or neoprene — in the 80–90 Shore A hardness band, and the GANA Glazing Manual places two blocks at the glass quarter points with length scaled to glass area. The sizing arithmetic, the edge-clearance rules, and an interactive GANA sizing helper are on Curtain Wall Glazing & Perimeter, which is the canonical page for setting blocks at every scale; specify the hardness band on the drawing rather than the chemistry alone. [6] [7]

Chemistry and density. BGT is a closed-cell crosslinked polyethylene tape in three thickness classes (1032/1016/1008 per the TDS designations): plasticizer-free, dimensionally stable, the drop-in default for shallow residential sash pockets and the low-risk pairing against silicone IGU edge seals.

PVC glazing tape is a denser closed-cell plasticized PVC foam in 15# and 25# density classes: higher compression-deflection bedding for deeper pockets, heavier commercial frames, and acoustic IGUs, with the caveat that plasticized PVC near silicone sealants deserves a compatibility check (plasticizer migration). Foam methods: ASTM D3575 for the XLPE, D1667 for the PVC, both on the TDS. [13]

Match the chemistry to the dominant aging mechanism. EPDM has the better UV and ozone resistance, so it owns exposure-driven positions: exterior weatherstrip and perimeter gaskets, with the RE-series blend for commercial-class and coastal exposure and solid 553/563 EPDM sheet where the joint is designed for a dense strip (ozone tested per ASTM D1149 on the TDS). Neoprene (SCE series) tolerates abrasion and incidental oil better, so it owns wear-driven positions: hinged patio doors, entry doors, operating commercial windows, threshold contact.

Both families step through four ASTM D1056 firmness grades; pick the family for the failure mode, then the grade against the closing force. [10]

Standard H-O Mount carries an acrylic PSA that bonds well to bare and anodized aluminum, rigid vinyl, sealed wood, and most painted surfaces. Powder-coated aluminum and true low-surface-energy composites (polypropylene-rich profiles, some capstocks) are a different story: a general-purpose acrylic may not wet them out, and the bond peels under its own preload weeks later. For those faces an LSE-variant acrylic PSA is available across the tape families.

The practical rule: send the frame substrate TDS or a physical sample with the RFQ and H-O engineering qualifies the bond on the real face during quote review. Peel is reported per ASTM D3330 on the tape TDS.

H-O and converts. We take roll, sheet, and bun stock from the foam and tape manufacturers and die-cut, kiss-cut on liner, slit, and laminate it to your drawing; we do not extrude or mold rubber profiles in-house. If your design needs an extruded bulb or leaf profile alongside corner gaskets and pads, we coordinate the extrusion through a partner network and convert the rest.

What we do in Winsted, Connecticut is precision conversion: die-cut gaskets matched to the extrusion geometry, kiss-cut-on-liner parts for line peel-and-stick, multi-layer laminations, and lot-code material traceability under an ISO 9001:2015 certified quality system. Send the drawing and engineering will scope the split.

Yes, in most cases. Send the incumbent TDS, part drawings, or physical samples and engineering will cross-reference to a family we convert, matching on the properties that drive the interface: foam chemistry and cell structure, ASTM D1056 compression-deflection class, thickness class, adhesive system, and the aging data lines (D1149 ozone, D573 heat) relevant to the position.

We provide an engineering cross-reference, not a guaranteed drop-in: the recommendation is comparable on the spec-relevant properties and verified against the vendor TDS for your application before quoting, and for certification-sensitive positions we will ask for the NAFS class and the test history so re-qualification risk is called out honestly.

Second-source qualification is one of our most common engagements.

H-O is a die-cutter and converter, so every fenestration component is made-to-order to your drawing, including samples and prototypes. We maintain working relationships with the foam and tape manufacturers behind the families on this page and keep common materials on hand for faster turnaround.

Samples typically ship in 3–5 business days for common configurations on materials we keep on hand. Standard production runs ship about 2 weeks after drawing approval, including kiss-cut-on-liner and laminated configurations. Expedited service is available when a certification window is closing. MOQ varies by material and part; prototype quantities through full production runs are equally accepted. Send the drawing and quantity through the form below for a specific lead-time commitment with your quote.