The best PU sealant with good weather resistance, with priority given to single component, moisture curing, modified/weather resistant PU. It can generally be used outdoors for 10-20 years without yellowing, powdering, and maintaining good elasticity. Below, we will explain everything in one go, including “how to choose+recommended models+key parameters+avoiding pitfalls”.
1、 Core requirements for weather resistant PU sealant (must see)
When choosing, focus on these few options for stable weather resistance:
Type: Single component moisture cured PU (no need for adhesive, simple construction)
Temperature resistance: -40 ℃ to+90 ℃ (short-term up to 120 ℃)
UV/aging resistance: no cracking, powdering, or obvious yellowing for 15-20 years outdoors
Displacement capability: ≥ ± 25% (joint expansion and contraction are not easy to crack)
Elongation rate: ≥ 400%, good elasticity
Modulus: Medium to low modulus (less prone to hardening and cracking)
Substrate adaptability: Concrete, stone, metal, glass, wood, PVC can all stick together, and damp substrates can also be used for construction
2、 Mainstream models with good weather resistance (buy directly from)
1) Puseida 9795/8791 (weather resistant modified PU, strong in both industrial and construction)
Single component, moisture curing, no yellowing, excellent weather resistance
Surface dryness: ≈ 50 min; Curing: 3.3 mm/day
Hardness: Shore A 50; Elongation rate: 500%; Stretching: 4.0 MPa
Temperature: -40 ℃~90 ℃
Usage: Curtain wall, exterior wall, carriage, doors and windows, expansion joints
2) CIMC New Materials PU107 (a versatile building weather resistant product with high cost-effectiveness)
Single component, high thixotropy, no sagging, aging resistance ≥ 10 years
Low VOC, odorless, and oil tight
Temperature: -40 ℃~90 ℃
Usage: Building facade joint filling, exterior walls, doors and windows, replacing silicone adhesive
3) 3M 560 (high-strength+UV resistant, automotive/cabin/metal bonding)
Single component wet curing, good UV resistance and high strength
Stick metal, plastic FRP、SMC、 timber
Usage: Vehicle panels, carriages, bonding of dissimilar materials, replacement of rivets
560 polyurethane sealant
4) 25HM weather resistant PU (building curtain wall/expansion joint, 20-year service life level)
± 25% displacement capacity, outdoor for 20 years+
Construction can be carried out on damp substrates with low odor
Usage: Building expansion joints, parapets, curtain walls, roof waterproofing
25HM polyurethane building sealant
5) Nitoseal PU50 (Silane modified PU, better weather and moisture resistance)
Single component, anti sagging, medium modulus
Damp surface tolerance (available on damp surfaces)
Building expansion joints, door and window perimeter, floor joints
