Polyurethane Sealants and Adhesives

PROSERIES Flexiseal Industrial Grade Sealant

Flexiseal Sausage Image

PROSERIES Flexiseal Sealant is a one component polyurethane that is tough, fast curing and permanently elastic for flexible bonding and sealing. It has excellent sealing properties, is weatherproof, and suitable for indoor & outdoor applications. It is sandable and paintable when cured. It is available in white, black and grey.


ProSeries Flexiseal Sealant is ideal for sealing expansion and construction joints between common building materials in vertical and horizontal surfaces such as:

  • Joints in precast elements
  • External wall and cladding joints
  • Weatherproofing joints between brickwork, masonry, wood concrete or metal frames
  • Joints in walls, balconies, around window or door frames
  • Joints in bridge and balcony parapets
  • Retaining walls
  • Roofing

For best performance, install backing rod (polyethylene or polyurethane foam rod) in joint to control sealant depth and ensure free movement* of sealant in joints. Remove masking tape before sealant skins.

Sealant must adhere to sides of the joints only and NOT to the back, so that it is free to stretch.

Priming: ProSeries Flexiseal Sealant is generally has good adhesion properties without priming to common building materials indicated. Pre-test to ensure adhesion is suitable.

Product Range

Product Code: 9300697123305

  • Size & Pack Type: 600mL Foil sausage
  • Color: White

Product Code: 9300697123312

  • Size & Pack Type: 600mL Foil sausage
  • Color: Grey

Product Code: 9300697123329

  • Size & Pack Type: 600mL Foil sausage
  • Color: Black

Technical Features

  • High flexibility
  • Low modulus of elasticity (Easy to stretch)
  • Excellent resistance to aging and weathering
  • No shrinkage during curing
  • Excellent adhesion on common building materials such as concrete, masonry, brick, ceramic tile, metals, soft wood, hardwood and plastics
  • High movement capability – +/- 25% joint movement. [Complies with ISO 11600/F/25LM]
  • Thixotropic (Non Slumping)
  • Permanently elastic over a wide range of temperatures
  • Paintable – can be painted with many water and solvent based paints ( pre-testing paint is recommended).
  • Undercoat with waterbased paint first.

Note: will not adhere to polyethylene or polypropylene – test other plastic first

Application Tips

  • Requires atmospheric moisture to cure
  • Not recommended for continuous submersion or below water line use
  • Do not apply in the presence of curing silicone sealants as cure will be affected
  • Avoid contact with alcohol and other solvent cleaners during curing
  • Application to substrates with high moisture can cause bubbling within the sealant
  • Do not use for structural or general glazing
  • Avoid air entrapment while applying sealant
  • May affect drying of alkyd /oil based paints
  • White sealant will yellow slightly with age and exposure to the sun
  • Do not store product above 30°C
  • Do not use on Polystyrene (adhesive failure)

Technical Details and Performance
Indicative information only, not to be used for setting specifications.


Thixotropic paste

Chemical type


Curing method

By reaction with moisture from the air and surrounding materials

Specific gravity


Tack free time @ 23°C; 50% R.H

100 – 120 minutes

Curing time @ 23°C; 50% R.H

3mm/24 hours

Application temperature

+5°C to +30°C

Service temperature

–40°C to +80°C

Shore A Hardness (DIN 53505)

15 – 20

Elongation @ break (DIN 53504)

+ 600%

Elastic modulus @ 100% (DIN 52455)

Approx 0.3N/mm2

Tensile strength (DIN 53504)

Approx 1.1 N/mm2

Elastic recovery (DIN EN 27389)


Theoretical coverage

(Joint Height x Joint Width) x Sausage mL x 1,000

Joint & sealant dimensions

The optimum width to depth ratio for expansion joint sealing is 2:1
For joint widths up to 12mm: Width/depth = 1/1 or w=d
Minimum sealant depth = 6mm
For joint widths 12mm – 35mm: Width/depth = 1/0.5 or w=2d