Sikaflex-1a - One Part Polyurethane Sealant/Adhesive - Construction Product Data Sheet

Nov 1, 2026

Sikaflex®-1a is a premium-grade, one-component, moisture-cured polyurethane elastomeric sealant/adhesive designed for a wide range of construction joints. It is non-sag, suitable for vertical and horizontal applications, and provides fast tack-free and final cure performance with high elasticity and excellent cut/tear resistance. The product bonds strongly to most substrates without primer, resists weathering and aging, and supports up to ±35% joint movement. It is odorless, non-staining, paintable, resistant to jet fuel, and certified to NSF/ANSI Standard 61 for potable water. Typical coverage, curing parameters, chemical resistance guidance, and storage requirements are included.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages2

Reading Time5 min

AccessFree to download

Product Overview

Where to Use

Advantages

Chemical Resistance

Packaging

Typical Data

Storage Conditions

Colors

Application Temperature and Service Range

Curing Rate

Movement and Mechanical Properties

Weathering Resistance

Coverage and Use

Coverage Yields by Cartridge/Sausage/Drum

How to Use - Surface Preparation

Priming

Application

Construction Product Data Sheet Edition 7.6.2017 Sikaflex-1a Sikaflex®-1a One part polyurethane, elastomeric sealant/adhesive | Description | Sikaflex-1aisa premium-grade, high-performance, moisture-cured, 1-component, polyurethane-based, non-sagelastomeric sealant. Meets Federal specification TT-S-00230C, Type II, Class A. Meets ASTM C-920, Type S, Grade NS, Class 35, use T, NT, O, M, G, I, A; Canadian standard CAN/CGSB 19. 13-M87 . | | --- | --- | | Where to Use | n Designed for all types of joints where maximum depth of sealant will not exceed 1/2 in.
n Excellent for small joints and fillets, windows, door frames, reglets, flashing, common roofing detail applications, and many construction adhesive applications.
n Suitable for vertical and horizontal joints; readily placeable at 40°F.
n Has many applications as an elastic adhesive between materials with dissimilar coefficients of expansion.
n Submerged conditions, such as canal and reservoir joints. | | Advantages | n Eliminates time, effort, and equipment for mixing, filling cartridges, pre-heating or thawing, and cleaning of equipment.
n Fast tack-free and final cure times.
n High elasticity-cures to a tough, durable, flexible consistency with exceptional cut and tear-resistance.
n Stress relaxation.
n Excellent adhesion-bonds to most construction materials without a primer.
n Excellent resistance to aging, weathering.
n Proven in tough climates around the world.
n Odorless, non-staining.
n Jet fuel resistant.
n Certified to the NSF/ANSI Standard 61 for potable water.
n Urethane-based; suggested by EPA for radon reduction.
n Paintable with water- , oil-and rubber-based paints.
n Capable of ±35% joint movement. | | Chemical Resistance | Good resistance to water, diluted acids, and diluted alkalines. Consult Technical Service for specific data. | | Packaging | 10.1 fl. oz. (300 mL), 20 fl. oz. (591 mL), 4.5 gal (17 L) in a 5 gal pail, 52 gal (197 L) in a 55 gal drum | Typical Data (Material and curing conditions @ 73°F (23°C) and 50% R.H.) RESULTS MAY DIFFER BASED UPON STATISTICAL VARIATIONS DEPENDING UPON MIXING METHODS AND EQUIPMENT, TEMPERATURE, APPLICATION METHODS, TEST METHODS, ACTUAL SITE CONDITIONS AND CURING CONDITIONS. Shelf Life 10.1 fl. oz. cartridges 12 months 20 fl. oz. uni-pac sausages 12 months 5 gallon pail 6 months 55 gallon drum 6 months Storage Conditions Store at 40°-95°F (4°-35°C) . Condition material to 65°-75°F before using. VOC Content 40 g/L Colors White, colonial white, aluminum gray, limestone, black, dark bronze, capitol tan, stone and medium bronze. Special architectural colors on request. Application Temperature 40° to 100°F. Sealant should be installed when joint is at mid-range of its anticipated movement. Service Range -40° to 170°F Curing Rate Tack-free time 3 to 6 hours Tack-free to touch 3 hours Final cure 4 to 7 days Tear Strength (ASTM D-624) 55 lb./in. Shore A Hardness (ASTM C-661) 21 day 40±5 Movement Capability (ASTM C-719) +/-35% Tensile Properties (ASTM D-412) 21 day Tensile Stress 175 psi (1 .21 MPa) Elongation at Break 550% Stress at 100% 85 psi (0 .59 MPa) Adhesion in Peel (TT-S-00230C, ASTM C 794) Substrate Peel Strength Adhesion Loss Concrete 20 lb. 0% Aluminum 20 lb. 0% Glass 20 lb. 0% Weathering Resistance Excellent PRIOR TO EACH USE OF ANY SIKA PRODUCT, THE USER MUST ALWAYS READ AND FOLLOW THE WARNINGS AND INSTRUCTIONS ON THE PRODUCT’S MOST CURRENT PRODUCT DATA SHEET, PRODUCT LABEL AND SAFETY DATA SHEET WHICH ARE AVAILABLE ONLINE AT [HTTP://USA.SIKA.COM/ OR BY CALLING SIKA](HTTP://USA.SIKA.COM/ OR BY CALLING SIKA)’S TECHNICAL SERVICE DEPARTMENT AT 800.933.7452 NOTHING CONTAINED IN ANY SIKA MATERIALS RELIEVES THE USER OF THE OBLIGATION TO READ AND FOLLOW THE WARNINGS AND INSTRUCTIONS FOR EACH SIKA PRODUCT AS SET FORTH IN THE CURRENT PRODUCT DATA SHEET, PRODUCT LABEL AND SAFETY DATA SHEET PRIOR TO PRODUCT USE. Constru

FAQs

What kinds of joints is Sikaflex-1a intended for?

Sikaflex-1a is designed for construction joints where maximum sealant depth does not exceed 1/2 in. It suits small joints, fillets, windows, door frames, reglets, flashing, roofing details, and many adhesive applications, including vertical and horizontal joints.

Does Sikaflex-1a require mixing or priming?

It is a one-part product that eliminates the need for mixing, filling cartridges, pre-heating or thawing, and equipment cleaning. Priming is typically not necessary, and is only required if testing indicates it or if water immersion after cure is expected.

What are the typical curing and service performance characteristics?

Tack-free time is 3 to 6 hours (touch-ready around 3 hours) and final cure occurs in 4 to 7 days. It supports about ±35% joint movement and offers excellent weathering resistance across the listed service temperature range of -40° to 170°F.

Nov 1, 2026

Uploaded by MrHarris58