Frequently Asked Questions
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Frequently Asked Questions

Is XYPEX HD-150 Toxic?

No, XYPEX is approved for use in potable water tanks and cisterns.

Does XYPEX produce any fumes when applied?

XYPEX does not produce ANY fumes.

Can XYPEX be applied to surfaces other than concrete?

XYPEX is designed to penetrate and react with the mineral constituents of cement-based materials. It can be applied on concrete, concrete-block, cement stucco or the mortar between bricks.

Can XYPEX be applied to concrete floors?

Yes, XYPEX can be applied to concrete floors. Smooth floor surfaces should be roughened to "open" the porosity and permit the penetration of XYPEX's active ingredients.

Can XYPEX be applied over paint?

Because the active ingredients in XYPEX penetrate into the concrete, a clean, bare surface is required. Painted surfaces must be stripped. This can be achieved with grinders (contact your local tool rental shop) or chemical strippers. If small spots of paint remain, XYPEX can be applied over them.

Can paint be applied over a XYPEX application?

Paint can be applied over a XYPEX application. We recommend that 21 days be allowed prior to painting. A mild muriatic acid or vinegar wash is recommended prior to painting.

Why must the concrete be wet prior to a XYPEX application?

The active ingredients in XYPEX penetrate the concrete by a process of chemical diffusion in which chemicals in a highly concentrated solution (the XYPEX slurry mixture) will spread through a solution of lower density (water in the pores and capillaries of the concrete) until the two are equalized.

Is XYPEX available in colors?

XYPEX is available in gray and white. Concrete Pigments can be added to XYPEX powder prior to mixing with water to add color to the surface.

Does XYPEX work on brick?

XYPEX is chemically reactive with cement and will therefore not work on clay bricks. It will work on the cement mortar between the bricks. Old brick foundation walls can be waterproofed by applying a coat of XYPEX followed by a cement

Can XYPEX be used to waterproof cracks and the floor/wall joint?

Construction joints, cold joints and cracks larger than a "hairline" should be cut or chiseled open to form a narrow groove which is then filled with a blend of hydraulic cement and XYPEX.

Can XYPEX be used in potable water cisterns or tanks?

XYPEX has been approved by NSF and many other government agencies for use in potable (drinking) water tanks and cisterns.

Does XYPEX cause any fumes?

XYPEX does not produce any fumes or odors.

Can XYPEX be applied to stone foundation walls?

Water seepage through stone foundation walls usually occurs through the mortar between the stones, or through cracks between the mortar and the stones. XYPEX can be used to waterproof these problems.

Will XYPEX work on Concrete Block (cinder block) walls?

Because of the high porosity of concrete blocks, two coats are recommended. XYPEX reacts with cement, therefore the blocks should have a minimum cement content of 10%. Applying XYPEX on the interior face of a block wall will not prevent water from seeping through the exterior surface into the hollow space inside the blocks.

Is more than one coat required?

Two are recommended on concrete block, very porous cast-in-place concrete, or the mortar in stone foundation walls.

Can XYPEX be applied if the concrete or block surface is crumbly?

Yes. Because XYPEX is applied as a cement-based slurry mixture, it will adhere well to crumbly surfaces.

Will XYPEX prevent the growth of fungus and mildew?

By preventing the flow of moisture through concrete, XYPEX prevents the damp conditions which are necessary for the growth of toxic fungus and mildew.

Is XYPEX Safe for fish or other aquatic life?

Yes, XYPEX is non-toxic and safe for fish. However, because XYPEX is alkaline like concrete, we recommend checking the pH level of the water prior to putting fish in the pond. If the pH is higher than required, either allow it to naturally lower itself or neutralizing with chemicals. Check with your pool chemical dealer.


XYPEX and HD-150 are trademarks of Xypex Chemical Corporation.
© 2002 Xypex Chemical Corporation. All rights reserved.