Dry, damp and wet cracks
Flexible sealing of cracks in walls, floors and concrete structures. The absence of water in a crack does not prevent components A and B from reacting.
CRACK SEALING
CrackFlex
Polyurethane injection resin · two-component · flexible
| Base / system | Polyurethane (PU) · 2 components (A + B) |
|---|---|
| A : B ratio | 1 : 1 by volume |
| Mixture viscosity | approx. 140 mPa·s at 23°C |
| Mixture density | 1.08 g/cm³ at 23°C |
| Reaction with water | Water is not required; slight foaming occurs in its presence |
| Application temperature | Above +5°C; air and substrate up to +40°C |
| Pot life | 30 min at 20°C ↘ |
| CE marking | CE marking indicated in the manufacturer's declaration of performance for concrete injection. |
| Pump / delivery method | 1K pump after mixing A + B, or a 2K pump with separate circuits at a 1 : 1 ratio by volume. |
Flexible sealing of dry, damp and wet cracks in concrete. Scope of use and limitations ↓
CRACK SEALING
Technical data
Parameters of components A and B and the mixture. Read values together with the measurement temperature and test conditions.
Open full documentation ↓| Parameter | A | B | Mixture |
|---|---|---|---|
| Viscosity mPa·s | 300 ± 50 | 50 ± 20 | approx. 140 |
| Density g/cm³ | 1,02 | 1.14 | 1.08 |
- A : B ratio
- 1 : 1 by volume
- Application temperature
- Above +5°C; up to +40°C for air and substrate
- Storage
- +10 to +30°C, in a dry place
- Shelf life
- 12 months from manufacture, in the original, unopened packaging
The instructions require material, ambient and substrate temperatures above +5°C. Shelf life is reduced after opening the packaging. Selection requires a trial under the conditions of the task.
State change and curing times
| Mixture state | At +12°C | At +25°C |
|---|---|---|
| Mixture is no longer liquid | 10 hours | 6 hours |
| Full cure | 7 days | 5 days |
Pot life and application conditions
The working time is 30 min at 20°C. Water, moisture and elevated temperature accelerate the reaction. Plan mixing and application for the conditions of the task.
Confirm working time →CRACK SEALING
Applications and limitations
Material for flexible crack sealing. Selection requires an assessment of the substrate, water, movement and repair objective.
Connections requiring a flexible seal
Adhesion to the substrate and flexibility of the filling are important in moving connections. The movement range and suitability of the solution must be assessed for the specific task.
Underground structures and injection hoses
The technical data sheet covers sealing with injection hoses. Material selection and delivery must meet the requirements of the particular system.
Learn about use in hoses →Capillary barrier and sealing the masonry structure
CrackFlex can interrupt capillary water transport through horizontal injection or saturation of masonry. Assess material, thickness, absorbency and voids; design a continuous sealing zone and verify resin distribution in a trial. Select sealing scope and consumption for the structure.
Construction joints and penetrations
Sealing interfaces between concrete and concrete, masonry or stone, and spaces around penetrations requires assessment of the joint path, substrate preparation and outflow confinement. Control intense inflow first. Include joint movement assessment and watertightness checks in the method.
Active water ingress?
For an intense leak, first consider stopping the flow, then providing the appropriate seal. The instructions provide for a two-stage method with EasyInject or WaterStopper.
See the role of WaterStopper →Is the objective structural repair?
A requirement to transfer forces through the repaired crack calls for separate selection of the method. A flexible seal does not in itself confirm structural bonding.
Distinguish between repair objectives →CRACK SEALING
Crack injection diagram
The cross-section shows a borehole intersecting the crack, material delivery through a packer and observation of its passage to adjacent points.
1. Intersecting the crack
The borehole location follows from assessing the path of the gap, element thickness and selected angle.
2. Controlled delivery
Pressure is selected for the structure and crack. No single value is suitable for every task.
3. Observing passage
Outflow at the next point helps track the material path. Pressure alone does not confirm complete filling.
CRACK SEALING
Preparation and application
Summary of instructions for substrate preparation, mixing and resin delivery. Full requirements are given in the technical data sheet.
A1 part by volume
+B1 part by volume
Example ratio: 1 litre of A + 1 litre of B. Equal volumes do not mean equal masses — the components have different densities.
Assess the structure and clean the substrate
The substrate should be stable, sound and free from loose fragments and contaminants that reduce adhesion.
Prepare boreholes and seal the crack surface
Drill holes suited to the task, clean them and install packers. For sealing the prepared crack at the surface, the instructions specify CrackOn.5.
For a 1K pump, mix A and B at a 1 : 1 ratio by volume
Pour component B into A and mix thoroughly with a low-speed mixer. Prepare a quantity you can use promptly. Water, moisture and higher temperature accelerate the reaction.
Inject and observe
For a vertical crack, start at the lowest point. Observe the material passing to the adjacent packer, then move to the next injection point. Select pump operating parameters for the structure.
In the 2K configuration, clean the system with PI-CLEANER before the material sets. The instructions specify cleaning after application and during pauses exceeding 15 minutes, followed by maintenance with PI-SAVER. Consider the actual reaction time and pump instructions.
Material selection and preparation
CRACK SEALING
Product documentation
Technical instructions and component safety documents. Before use, confirm that they are current for the supplied material.
Component A documentationRequest the data sheet appropriate to the supplied component.
Enquire ↗Safe preparation and work
Read the documentation for both components before use. Use the required protective equipment and ventilation. Component B reacts with water and moisture, which may release CO₂ and increase pressure in a closed container.
Before delivery, confirm that the documents are current for the material ordered.
CrackFlex technical support
Material selection, application conditions and delivery documentation.