ASTM C920, ASTM C1193, ASTM C1330, AAMA 501.2, UL 2079, ASTM E119, SWRI Technical Guidelines

• Visual survey of all joints; document condition by location and joint type.
• Sealant service life assessment: age, durometer (Shore A), adhesion condition, movement crack evidence.
• Water hose testing (AAMA 501.2) at selected window and curtain wall locations.

• Remove all existing sealants mechanically to bare substrate — no chemical strippers.
• Remove backer rod; clean all joint faces; allow to dry minimum 4 hours.
• Mask both sides of joints; remove masking immediately after tooling.

• Install closed-cell backer rod sized 25–33% larger than joint width.
• Install bond breaker tape at three-sided joints; apply primer where required.
• Tool to smooth concave profile; check depth-to-width ratio (max 1:2).

• Structural silicone (DOWSIL 983, Tremco Proglaze ETA): curtain wall glazing; certified applicator required.
• High-movement silicone ±50% (DOWSIL 790/795): expansion joints; masonry-to-metal facades.
• Polyurethane (Dymonic 100, Sika 1A): general facade joints; concrete joints; paintable.
• Pre-compressed foam (Willseal 150/300): rapid installation; no backer rod required.
• Fire-rated (3M Fire Barrier 1000 NS): per UL 2079; 1–4 hour rated systems.

Field adhesion test per ASTM C1193 on minimum 3% of completed linear feet. Water hose test per AAMA 501.2 on minimum 10% of sealed window perimeters after cure.