Setting blocks are extruded components designed to properly position and support glass, insulated glass units (IGUs), or panels within window, door, curtainwall, and storefront framing systems. These blocks ensure uniform edge clearance, proper weight distribution, and protection against edge damage during installation and throughout the product’s service life. In the manufacturing environment of residential windows and doors, setting blocks are also known as “spacers” since their primary use is to space the glass evenly within the frame. Used by glazing contractors, fabricators, and OEMs, they are an essential part of achieving long-term glazing performance and compliance with industry standards.
Function and Application
Setting blocks maintain the correct alignment of glass within the frame channel, isolating the glass from metal contact while allowing for expansion, contraction, and load transfer. Properly sized and placed blocks prevent glass breakage from edge stress, minimize sealant failures, and absorb vibration and shock. They are used in vertical and horizontal installations, including fixed windows, sliding doors, curtain walls, and structural glazing systems.
Available Options
Meltpoint Plastics manufactures setting blocks in multiple materials, hardness ranges, and dimensions to suit specific system designs and environmental conditions:
Materials Offered:
o EPDM Rubber: Excellent weathering, UV, and ozone resistance; ideal for exterior glazing, railing systems
o Silicone: Superior high-temperature stability and long-term resilience. Comonly used when structural silicone is present in the assembly process
o TPE: Cost-effective options for controlled environments or light commercial use.
· Hardness (Durometer): Typically ranges from 70 to 90 Shore A, depending on glass weight and frame type.
· Standard Sizes:
- Thickness: 1/16″ (1.6 mm) to 1/2″ (12.7 mm)
- Width: 1/4″ (6.4 mm) to 1″ (25.4 mm)
- Length: Standard 2″ (50.8mm) & 4”(101.6 mm) or cut-to-size per specification
· Custom sizes, shapes, and cut lengths are available to meet specific design and installation requirements.
- Continuous extruded rolls can be supplied
Industry Standards and Guidelines
These standards should be reviewed to confirm that your application meets the required specifications for each job requirement;
- ASTM C864 — Specification for Dense Elastomeric Compression Seal Gaskets, Setting Blocks, and Spacers.
- ASTM C920 — Elastomeric Joint Sealants (for compatibility reference).
- ASTM C1036 / C1048 — Flat Glass and Heat-Treated Glass Standards (for installation parameters).
- GANA Glazing Manual — Guidance on setting block placement, spacing, and load distribution.
Proper selection and placement should follow manufacturer recommendations to maintain compliance with these norms and ensure glass warranty validity.
Why Choose Meltpoint Plastics Setting Blocks
Our precision-extruded setting blocks are manufactured to RMA (Rubber Manufacturers Association) standards tolerances, ensuring consistent thickness, accurate durometer, and uniform density throughout each batch to satisfy the demands of today’s glazing professionals.