+49 40 670 570






Crack Repair

Closing, sealing, limited flexibility bridging or bridging where structural strength is required

Crack repair: injection resins and methods of crack filling in masonry and concrete

WEBAC offers one of the most extensive and efficient product ranges for tear repair and gap repair worldwide. The products are suitable for restoring various mineral structural elements at different crack widths, moisture conditions and application temperatures.

Especially if cracks in masonry or cracks in concrete affect the stability of building structures, they must be filled. Various injection resins and methods are available for tear repair and gap repair – depending on the envisaged objective of the restoration.

Crack repair: products for the restoration

The suitable injection product for crack filling and gap filling in masonry must be selected depending on the objective of the restoration and the moisture condition.

WEBAC EP Injection Resins (category F)
For structural bonding (filling) when repairing cracks in concrete, mainly low viscosity 2C epoxy injection resins are used.

WEBAC PU Injection Resins (category D)
For limited-flexibility crack filling, structures are required which do not cause the injection product to fail even if the entire cracked surface is exposed to expansion and compression movements.

Water stop with PU Injection Foam Resins
Crack filling is generally impossible in case of (highly) pressing water. First of all, the water flow must be stopped locally in the context of the restoration. 


Crack repair: techniques for the restoration

WEBAC Injection Pumps  

  • 1C injection pumps
    When applying WEBAC PU/EP injection resins using 1C pumps for the restoration, both components must first be mixed and then filled into the pump's hopper for further use.
  • 2C injection pumps
    Application with a 2C pump is possible at a mixing ratio of 1 : 1. When using 2C pumps, both components are first introduced to the mixing head separately where they are mixed for the restoration. This pump technology is especially recommended when applying very fast reacting WEBAC PU injection resins and large quantities of material. 

WEBAC Injection Packers
Injection packers are filler necks which connect the structural element to the injection pump during the injection process. Depending on the type of connection to the construction element one distinguishes between drill-hole packers and surface packers.


Application of WEBAC injection resins

WEBAC EP putties and adhesives
For gap filling and crack filling, WEBAC EP putty is used to patch cracks and to install surface packers. 

The nature and condition of the building structure is decisive for the injection pressure. The cracks are injected against gravity from bottom to top until injection material emerges from the adjacent packers and the structural element's surface. A secondary injection is necessary to completely fill the cracks.

Impregnation/grouting of cracks and surfaces
Cracks near the surface can be closed and surfaces affected by craquelure be filled without pressure using injection products with a good wetting effect. Grouting of cracks works well on horizontal or slightly inclined surfaces. The permanent crack filling effect depends on the penetration depth. It is mainly determined by the viscosity development, the wetting effect of the injection products and the width of the cracks.

Special applications of WEBAC injection resins

Masonry is an inhomogeneous structure which can like highly porous concrete elements (tamped concrete) be statically strengthened using special PU injection resins. PU resins used for damp-proof courses provide for the sealing effect in crack repair, tear repair and gap repair.  

  • WEBAC PU injection resins for static stabilization
    • WEBAC® 1610
    • WEBAC® 1660
  • WEBAC PU injection resins for sealing structures
    • WEBAC® 1401
    • WEBAC® 1403
    • WEBAC® 1404
    • WEBAC® 1420
    • WEBAC® 1440