Custom Construction Materials: Weatherseals, Movement-Joint Seals, Isolation Pads, Firestop & Dielectric Barriers
H-O Products converts EPDM closed-cell foam, silicone sponge, neoprene sponge, dense elastomeric block stock, impregnated and reticulated polyurethane foam, closed-cell polyethylene backer, cork-rubber, mica sheet, glass-fibre paper, glass-epoxy (FR-4) laminate, aramid paper, glazing and butyl tapes, and low-tack protective film into die-cut weatherseals, rainscreen and curtain-wall joint gaskets, movement-joint seals and backer, equipment-isolation and bearing pads, smoke-seal and firestop-adjacent gaskets, non-combustible mica and glass-fibre barriers, panelboard dielectric barriers, closed-cell pipe-insulation collars, and construction surface-protection parts for envelope, facade, mechanical, acoustic, life-safety, and building-electrical contractors and OEMs.
Material grades are referenced by designation (ASTM, AAMA, UL, NFPA) per the vendor TDS. Made to your drawing under an ISO 9001:2015 certified quality management system in Winsted, Connecticut. Extruded gasket profiles are coordinated through the partner network.
Where do you need a converted part?
Every application area is a dedicated page with its material families, failure modes, decision matrix, and its own intake form. All ten publish together with this hub. Pick the area that owns your problem; H-O converts the parts for it to your drawing.
Envelope & Glazing · 01
Building Envelope Sealing
The compression seals, weatherseals, and foam closures that control air, water, and vapor at envelope joints: EPDM and silicone for UV and ozone-exposed weatherseals, closed-cell PVC and neoprene sponge for economical closed-cell sealing, and reticulated PU weep baffles that drain a pressure-equalized cavity. Air and water infiltration ratings (ASTM E283 / E331) belong to the tested assembly.
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Envelope & Glazing · 02
Roofing, Cladding & Structural Glazing
The wall and roof around the glazed unit: EPDM and cellular-silicone rainscreen and curtain-wall joint gaskets (ASTM C864 / C509), profiled metal-roof closures and butyl seam seals (ASTM D1056), and the isolator pads and strips where anchor clips and cladding brackets land on structure. Wind-load ratings (ASTM E330) belong to the tested assembly.
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Movement & Acoustic · 03
Expansion Joint Systems
The sealing materials that stay watertight while a movement joint opens and closes: precompressed impregnated-PU foam sealant tape sized to the joint's movement capacity as a percent of joint width, closed-cell EPDM, neoprene, and silicone compression seals, and closed-cell backer (ASTM C1330 Type C). Fire-rated joints are rated at the tested-system level (ASTM E1966 / UL 2079), not per material.
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Movement & Acoustic · 04
Acoustic Isolation & Sound Control
The resilient, barrier, and sealing that let rated walls and floors perform in the field: isolation pads and perimeter gaskets under partitions and floors, resilient clip and hanger pads, floor underlayment, and acoustic sealing gaskets at penetrations. STC and IIC are single-number ratings of the tested assembly (ASTM E90 / E413, E492 / E989), never of a part; isolation is distinct from absorption.
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Equipment, Bearing & Protection · 05
Mechanical Equipment Isolation
The load-bearing vibration-isolation pads under building mechanical equipment: ribbed and waffle neoprene, cork-rubber composite, high-density rebonded neoprene, EPDM outdoor pads, and PORON precision pads under RTUs, AHUs, chillers, pumps, and gensets. The pad is a spring tuned by static deflection, sized so its bearing stress stays in the working range; the community and acoustic result belongs to the installed building.
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Equipment, Bearing & Protection · 06
Bearing Pads & Structural Isolation
Structural and leveling bearing pads for precast, steel, and setting-block joints: plain elastomeric pads per ASTM D4014 / AASHTO M251, cork and cork-rubber leveling pads, and rebonded elastomer, sized by allowable compressive stress and rotation. The engineer of record checks the bearing; H-O converts the pad to the drawing.
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Equipment, Bearing & Protection · 07
Construction Surface Protection
Temporary protection for finished work: low-tack and self-cling films, SAE felt, crosslinked-PE foam, and die-cut edge and corner guards for floors, glazing, countertops, and elevator cabs — specified by the clean-removal window on the film TDS, and slit, die-cut, and kitted to the trade package.
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Fire, Smoke & Thermal · 08
Fire, Life-Safety & Smoke Control
The material stack that closes the gaps in fire, life-safety, and smoke-control assemblies: smoke-seal gaskets for fire and smoke doors and dampers, glass-fibre and mica non-combustible barrier die-cuts, and firestop-adjacent closures. Every fire, smoke, and leakage rating belongs to the tested or listed assembly (UL 1784, UL 555 / 555S, UL 1479 / ASTM E814); a gasket is never fire-rated or fireproof.
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Fire, Smoke & Thermal · 09
Duct, Pipe & Thermal Insulation
The flexible-insulation and gasket that keep a building's duct and pipe distribution thermally sound and condensation-free: closed-cell elastomeric collars and wraps for below-dew-point lines where low vapor permeance is the vapor retarder, duct-liner die-cuts, and duct-connection gaskets. On cold service the driver is dew point plus vapor drive (ASTM C534, E96); in plenums it is the 25/50 fire class (ASTM E84, NFPA 90A).
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Electrical · 10
Building Electrical & Arc Flash
The dielectric barriers, phase and compartment insulators, deadfront insulation, and enclosure gaskets inside commercial and institutional building electrical distribution: panelboards, loadcenters, switchboards, MCCs, and generator, transfer-switch, and elevator-controller cabinets. Specify by dielectric strength (ASTM D149), UL 94 flame class, CTI, and thermal class; arc-flash and fire ratings live with the listed assembly and the facility NFPA 70E program.
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Glazed units themselves — window, door, and curtain-wall components, from setting blocks to glazing gaskets — are covered in the Fenestration industry hub.
Engineering resources for general construction
Selection guides, failure-mode notes, and project work from H-O engineering, matched to the applications on this page.
Send a drawing, detail, or a description of the application and what the part must do, and an engineer typically responds within one business day with a material-family direction and the matching application page. Material grades are referenced by designation per the vendor TDS; air, water, STC/IIC, fire, smoke, dielectric, arc-flash, and bearing performance belong to the tested or listed assembly and the facility program. Volumes, install method, and documentation requirements are reviewed at quote.
Last updated · Reviewed by H-O Products engineering (ISO 9001:2015 certified converter, Winsted, CT).
Get a construction materials quote
Send a drawing, a system-manual page, or a spec section; partial information is welcome. We typically respond within one business day with a material-family recommendation, the vendor technical data sheet behind it, a prototype lead time, and an honest note on anything that needs a listing holder or a sealant maker rather than a converter.