PU 300

PU 300 is a highly deformable, low modulus of elasticity, thixotropic sealant.

Product Description

PU 300 sets progressively by reacting with the water vapour in the air or in the pores in the substrate to form elastic, deformable rubber that adheres to the substrate. Once set, it compensates for compressive, tensile and torsional movements in joints while guaranteeing high resistance to punching and surface friction. PU 300 is resistant to dry service temperatures of -30°C to +80°C.

Field of Application

· Sealing internal and external expansion and distribution joints subject to movement up to 20%

· Application on façades and industrial buildings

· Application on pre-fabricated concrete panels

· Application in industrial floors subject to vehicular traffic

· Application in concrete floors for car-parks, supermarkets, shopping centers and warehouses

· Application on concrete walls and general internal and external vertical structures where the use of a thixotropic product is required.

Product Details

Product identity

Consistency: thixotropic paste
Color: grey
Density (kg/m³): 1450
Viscosity (mPa.s): 1,200,000
Dry solids content (%): 100


PU 300 is supplied in:
– 600ml cartridge


The consumption of PU 300 depends on the application. Typical consumption is between 120 and 150 ml/mL.

Application Procedure

Preparation of substrate

All the surfaces must be dry, sound and free of dust, crumbling parts, oil, grease, wax and old paint. To guarantee that the sealant works correctly, the joint must be free to expand and contract. Therefore, it is important that the product only bonds to the side walls of the joint, and never to the bottom. The size of the joint must be calculated so that, when in service, it expands less than or equal to 25% of its initial size. To regulate the depth of application and to avoid it sticking to the bottom of the joint, foam closed-cell, expanded polyurethane flexible cord with a suitable diameter must be inserted beforehand in the joint. To avoid the sealant spreading out of the joint, and to leave an attractive finish, we recommend using masking tape around the joints.

Preparing the product

Ready to be used.

Applying the product

Use specific manual caulking guns for 300 ml cartridges or 600 ml soft cartridges. Extrude the sealant into the joint in a continuous flow without entraining air. Immediately after applying the product smooth over the surface with a suitable tool kept constantly wet with soapy water.