FAQs

  • 1. What is Xypex?

    Xypex is a non-toxic, chemical treatment for the waterproofing and protection of concrete. Xypexs primary and most distinguishing performance feature is its unique ability to generate a non-soluble crystalline formation deep within the pores and capillary tracts of the concrete - a crystalline structure that permanently seals the concrete against the penetration of water and other liquids from any direction. Xypex crystalline products are dry powder compounds composed of Portland cement, silica sand and many active, proprietary chemicals.

  • 2. How is Xypex applied?

    Xypex crystalline technology is available in three forms: a) As a coating (for new or existing structures). b) As a dry shake material (for fresh horizontal surfaces). c) As an admixture (added at the time of concrete batching). These three options will prove an asset to the value-engineering process and to the flexibility of the construction schedule.
  • 3. How does Xypex work?

    To create its crystalline waterproofing effect, Xypex must become an integral part of the concrete mass. It does so by taking advantage of the natural and inherent characteristics of concrete; concrete is both porous (capillary tract system) and chemical in nature. By means of diffusion, the reactive chemicals in Xypex use water as a migrating medium to enter and travel through the capillary tracts in the concrete. This process precipitates a chemical reaction between Xypex, moisture and the natural chemical by-products of cement hydration (calcium hydroxide, mineral salts, mineral oxides and unhydrated and partially hydrated cement particles). The result is crystallization and, ultimately, a non-soluble crystalline structure that plugs the pores and capillary tracts of the concrete. In this condition, the pores become discontinuous and the concrete is thereby rendered impenetrable by water and other liquids from any direction. The Xypex crystalline process will activate whenever water is present.

  • 4. How long does Xypex last?

    A Xypex application, unlike most other systems, is permanent. Its unique, dendrite crystalline growth will not deteriorate under normal conditions. Since the process is catalytic, the crystalline structure can reactivate many years after the original application, to seal, or re-seal concrete shrinkage cracks up to 0.4 mm. It should be noted that Xypex products are not fluid and thus are not applicable to sealing live structural cracks on a stand-alone basis.

  • 5. How waterproofing is Xypex-treated concrete?

    A major independent testing laboratory performed concrete waterproofing tests on Xypex in accordance with Army Corps Permeability Specification CRD-C48-73. The results showed that a two coat application of Xypex on 50 mm thick 13.8 MPa porous concrete totally eliminates leakage at pressures of at least 123.4 m of head pressure (1207 kPa), the limit of the testing apparatus.

  • 6. Is a Xypex coating like that of a membrane?

    A coating of Xypex Concentrate and/or Modified is not a moisture barrier, and is never waterproof on its own. The coating is only a medium for allowing Xypex chemicals to be progressively drawn from the coating into the matrix of the concrete during the initial curing process. If required, the Xypex coating itself may be removed after 5 to 6 weeks, as the waterproofing (i.e. the crystalline growth) is deep into the concrete by this time.

  • 7. What are the advantages to using Xypex over membranes?

    • Xypex does not require dry weather, costly surface priming or leveling prior to application.
    • Xypex does not require a dry surface; in fact, a wet surface is necessary.
    • Xypex cannot puncture, tear, rupture or come apart at the seams.
    • Xypex does not restrict site access or require protection during back-filling, placement of steel, wire mesh or other materials.
    • Xypex does not require costly sealing, lapping and finishing of seams at corners, edges or between membranes.
    • Xypex is cheaper to purchase and apply than most membrane applications.
    • Xypex waterproofs and protects the whole of the structure, not just the surface.
  • 8. How resistant is Xypex to aggressive chemicals?

    Based on independent testing according to ASTM C 267-77 Chemical Resistance of Mortars, Xypex is not affected by a wide range of aggressive chemicals including mild acids, solvents, chlorides and caustic materials. Because Xypex is pH specific (not chemical specific), it will protect concrete from any chemical whose pH range is 3.0 to 11.0 constant contact, or 2.0 to 12.0 periodic contact.

  • 9. How resistant is Xypex to aggressive chemicals?

    Based on independent testing according to ASTM C 267-77 Chemical Resistance of Mortars, Xypex is not affected by a wide range of aggressive chemicals including mild acids, solvents, chlorides and caustic materials. Because Xypex is pH specific (not chemical specific), it will protect concrete from any chemical whose pH range is 3.0 to 11.0 constant contact, or 2.0 to 12.0 periodic contact.