1. Can Xypex be used against extreme hydrostatic pressure?

Yes. Because Xypex is not dependent upon adhesion to the concrete surface and, instead, becomes an integral part of the concrete mass, it is capable of resisting extreme hydrostatic pressure from either side (positive or negative) of the concrete. Independent laboratory testing in accordance with U.S. Army Corps of Engineers CRD C-48 “Permeability of Concrete” showed that Xypex- treated concrete withstood up to 405 feet (123.4 m) of head pressure (175 psi/1.2 MPa), the limit of the testing apparatus.

2. Does Xypex have any adverse effect on concrete?

No. The Xypex crystalline formation becomes a part of the concrete matrix itself and has no deleterious effect on the concrete. In fact, independent laboratory testing has shown that under most conditions Xypex enhances the strength and durability of the concrete structure.

3. Does Xypex protect concrete against freeze/thaw damage?

Yes. By blocking the intrusion of water into concrete, Xypex helps protect the concrete from the damaging effect of repeated freeze/thaw cycles.

4. Does Xypex protect reinforcing steel?

Yes. By preventing the intrusion of water, salt water, sewage, and most chemicals, Xypex helps protect reinforcing steel against oxidation and deterioration.

5. How deep does the Xypex crystalline formation penetrate the concrete?

The Xypex chemical reactions that initially take place at the concrete surface will continue deep into the concrete structure. Various factors affect the rate and depth of crystallization within the concrete. Some of these factors are: number of Xypex coats, mix design of the concrete, density, porosity, cement content, exposure to moisture and temperature. Independent testing measured the depth of Xypex crystalline penetration into a cast-in-place concrete block at 30 cm (approximately 12 inches). The test concrete sample was coated on the top surface with Xypex Concentrate and left outside the research laboratory in ambient temperatures for 12 months.

6. How is Xypex different from other products?

The Xypex crystalline system for concrete waterproofing and protection is substantially different from traditional barrier products (membranes, cementitious coatings, etc): 

  1. Xypex creates a crystalline structure deep within the pores and capillary tracts of the concrete mass to prevent the penetration of water and aggressive chemicals. In contrast, barrier type products function only at the surface of concrete.
  2. Xypex will seal hairline cracks up to 0.4 mm (1/64”).
  3. Xypex is not subject to the deterioration problems encountered by membranes.
  4. Xypex is designed to be permanent and reactivates whenever water is present. 

7. How long does Xypex last?

The Xypex treatment, unlike most other systems, becomes a permanent part of the concrete matrix. Its unique dendritic crystalline growth will not deteriorate under normal conditions, and the crystalline process will reactivate whenever water is present.

8. How resistant is Xypex-treated concrete to aggressive chemicals?

Based on independent testing according to ASTM C 267 “Chemical Resistance of Mortars”, the Xypex-treated concrete 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. In what forms is the Xypex Crystalline Technology available?

The Xypex crystalline technology is available in three forms:

  • As a Coating System (Xypex Concentrate & Modified) for new or existing structures
  • As a Concrete Additive (Xypex Admix C-Series) to be added at time of concrete batching
  • As a Dry Shake material (Xypex DS-1 & DS-2) for fresh horizontal surfacesThese three options will prove an asset to the value-engineering process and to the flexibility of the construction schedule.

10. Is Xypex toxic?

No. Xypex contains no volatile organic carriers (VOCs) and can be applied safely in enclosed surroundings. Xypex is approved by numerous health and water authorities around the world for use on structures that contain potable water or foodstuffs. A few of these agencies are:

  • NSF International
  • Swiss Federal Department of Health
  • Japan Food Research Laboratories
  • United Kingdom (DWI) Drinking Water Inspectorate
  • Australian Water Quality Centre
  • Singapore Institute of Standards and Industrial Research
  • France Research Centre for the Control of Water
  • Czech Republic Health Institute & Centre for Drinking Water

11. Is Xypex used to waterproof cracks, faulty joints and other defects in concrete?

Yes. Xypex has a specific repair system that utilizes its unique crystalline waterproofing technology to stop water flow through cracks, faulty construction joints and other defects. In the case of expansion joints or chronic moving cracks, a flexible sealant is recommended.

12. What are some typical Xypex applications?

Typical Xypex applications include reservoirs, sewage and water treatment tanks, secondary containment structures, tunnels, underground vaults, manholes, concrete pipe, foundations, pools, parking structures and below grade construction.

13. What makes Xypex unique?

Xypex becomes an integral part of the concrete mass itself. Traditional barrier products, on the other hand, rely solely on their performance at the surface of the concrete and are therefore subject to deterioration caused by exposure to the environment, hydrostatic pressure, puncturing, delamination, chemical erosion, and damage during backfilling. Xypex was developed to eliminate these very issues. The Xypex formula is based on the natural characteristics of concrete – the fact that concrete is both porous and chemical in nature. With moisture as the catalyst, Xypex’s proprietary chemicals react with the products of cement hydration to form a non-soluble complex within the pores, voids and capillary tracts of the concrete mass. From this inside position, Xypex renders the concrete impenetrable by water and other liquids from any direction, eliminates the problems normally associated with traditional barriers and, in the process, enhances the quality and durability of the concrete structure.