Sealers for concrete and masonry

• Thoroseal isa cement-based waterproof coating for concrete and masonry. It is NSF approved for sealing concrete or masonry tanks storing potable water. It is also used to seal the concrete base of culvert tanks. To waterproof such a tank it is typically used in conjunction with another product ACRYL 60, which improves the adhesion of the sealer to the tank. I have used this product to seal precast concrete septic tank cisterns.
Thoroseal is manufactured by Chemrex. www.chemrex.com.

In Tucson, Arizona it is available from Border Products, 623-4100

• Cement Slip (aka cement slurry or Nil) is NSF 61-certified Portland cement mixed with water to form a thin paste (no sand or gravel added).
It is used to seal cement, masonry, and ferrocement tanks. Apply the slip to a 1/4-inch thickness with a trowel on the same day the concrete tank is poured or plastered. Cover the tank with a tarp after the slip has been applied to keep humidity in the tank high and to prevent the slip from drying too fast and cracking. When the slip is firm, but still green spray it with water or set a bucket of water in the tank to enhance humidity, and cover the tank again with plastic or a tarp. Keep the slip moist and covered (shaded from the sun) for three weeks for thorough curing.

• Antihydro and Antihydro R are add mixtures of organic and inorganic chemicals used to waterproof concrete and increase its workability, strength, hardness, and durability. According to the manufacturer mixing Anti-hydro within a concrete mixture produces impermeable concrete that is hard, non-dusting & safe for potable water. Though I was not able to obtain information from the manufacturer on what entity approved the products’ use with potable water.
Anti-hydro is for the application of the product in temperatures below 85⁰F. Anti-hydro R is for the application of the product in temperatures exceeding 85⁰F.
Anti-hydro products are manufactured by Anti Hydro International, Inc. www.anti-hydro.com

• XYPEX HD-150is a concrete waterproofing coating approved by NSF for use in potable water tanks and cisterns. It must be applied to bare concrete only. According to a representative of the manufacturer, XYPEX HD–150 is marketed for homeowners, though it is the same product as XYPEX Concentrate marketed for concrete contractors.

XYPEX HD-150 is manufactured by XYPEX Chemical Corporation. 1-888-443-7922.
http://www.hi-dry.com/index.html

Sealers for gutters and between different materials such as concrete and metal or plastic and metal

• Sikaflex-1A is a moisture-cured, 1-component, polyurethane-based, non-sag elastomeric sealant. Can be used as an elastic adhesive between materials with dissimilar coefficients of expansion such as concrete and metal or plastic and metal.
I’ve used it to seal seams in gutters and seams around downspout pipes entering tanks. It is also used in culvert tanks to seal the seam between the metal culvert and concrete base (after the concrete has been sealed with Thoroseal), and the spiraling seam of the culvert itself. It is USDA-approved and NSF-approved for potable water contact.
Sikaflex-1a is manufactured by Sika Corporation http://www.sikaconstruction.com/con/con-prod-name.htm#con.prod-sikaflex1a

In Tucson, AZ it is available from Border Products, 623-4100

Sealer used to coat a variety of materials

• #432 Urethane is a liquid applied, single-component, moisture-cured polyurethane coating, designed to form a tough rubber membrane impervious to moisture. Once cured it allows expansion and contraction over a variety of surfaces, so it could be used to coat concrete and metal. It conforms to B.S. 6920 for use in contact with water intended for human consumption. #432 Urethane is NSF certified.
#432 Urethane is manufactured by GlobalShield, Inc. www.roofs-online.com and www.global-shield.com