Injection foam to prevent water ingress in structures

abe® PU injection foam is a liquid polyurethane polymer that reacts with moisture to produce a foam. A liquid catalyst, also provided, this when mixed in with the polyurethane polymer, accelerates the onset of foam formation. The rate of reaction can be controlled by the amount of catalyst added. abe® PU injection foam is typically used in mining and civil applications to fill voids and prevent water ingress.

  • Fissures and voids in rock strata in mining or civil works
  • Filling water bearing voids, cracks behind concrete and brickwork joints
  • Concrete reservoir cracks
  • Preventing medium water ingress in sub-terrain structures
  • Bonds well to wet surfaces
  • Reacts in moist surroundings
  • Absorbs limited movement
  • Quick reaction time
  • High expansion rate, up to 40 times
Typical Properties
abe® PU injection liquid polyurethane polymer
Appearance Brownish liquid
Specific gravity @ 25 °C 1.12 – 1.20
Viscosity 800 – 2000 MPa’s
% Non-volatiles 100%
abe® PU injection liquid catalyst
Appearance Clear to yellowish liquid
Specific gravity @ 20 °C 1.10
Viscosity 70 MPa’s
Reaction Time @ 25 °C with 10% water and 10% catalyst added
Mixing time ± 90 seconds
Tack free time ± 5 minutes
Expansion Up to 40 times original volume
Reation Time

The reaction time will depend upon the temperature of the environment, structure, water, product and the amount of catalyst added. It is recommended that site trials are carried out in order to determine the reaction time required.


Just prior to application in a clean mixing vessel add the abe® PU injection foam liquid polyurethane polymer followed by the abe® PU injection foam liquid catalyst and mix thoroughly until a homogenous mix is obtained. Avoid contact with water prior to use. The catalysed product will react when it comes into contact with water.


The abe® PU injection foam should only be applied by specialist applicators or contractors skilled in this area.
The abe® PU injection foam is to be injected into the appropriate area of application.


During intervals between product injection, the pump should be filled with non-catalysed product to avoid blockages. Upon completion of the injection process, pump oil that contains no water through the pump and lines to remove any polyurethane residue.


abe® PU injection liquid polyurethane polymer supplied in 21 kg kit (code: 19800021)

Handling & Storage

Sealed unused containers should be stored in a cool dry environment below 25 °C. Empty containers should not be resealed, and should be rendered unusable by knocking holes in the base and sides of the container to ensure that it unusable. The product reacts with water and liberates carbon dioxide gas which can lead to a dangerous build-up of pressure in closed containers.

abe® PU injection foam has a 6 month shelf life in unopened containers stored in dry cool conditions (20-25 °C).

Health & Safety

Product safety information required for safe use is not included. Before handling read product and safety data sheets and container labels for safe use, physical and health hazard information including disposal of product. The safety data sheet is available from your local abe® sales representative.

abe® PU injection foam should be treated as an isocyanate and the usual precautions should be exercised when dealing with this type of chemical. Protective clothing and air masks should be worn when working with this product; and the area should be well ventilated as breathing in the vapours can lead to sensitisation.

Important Notice

This data sheet is issued as a guide to the use of the product(s) concerned. Whilst a.b.e.®  endeavours to ensure that any advice, recommendation, specification or information is accurate and correct, the company cannot accept any liability for application – because a.b.e.®  has no direct or continuous control over where and how a.b.e.®  products are applied.

Further Information

Where other products are to be used in conjunction with this material, the relevant technical data sheets should be consulted to determine total requirements.

a.b.e.® has a wealth of technical and practical experience built up over the years in the company’s pursuit of excellence in building and construction technology.