Applying Iso-Tek 8501 to 432 Park Avenue

How One Developer
Solved an Absorption Challenge

Ghostshield® Iso-Tek™ 8501 offers an effective solution for architects, engineers, and builders looking to protect vertical high-density concrete commonly used in commercial and industrial construction. This technology is used on some of the most iconic structures — including the Big Dig, the Channel Tunnel, Bjarke Ingels Group’s Grove at Grand Bay, Water Street Development, Notre Dame, and the Zakim Bridge. Here is how Macklowe Properties utilized Iso-Tek™ 8501 to provide an unsurpassed level of protection on the 432 Park Ave project in New York City.

Top Challenges

14,000 PSI
High-Density Concrete
1,396 Feet
Vertical Surface Height
20 Years
Long-Term Protection

Stratospheric Ambitions

The goal: provide an invisible, protective barrier on vertical ultra high density concrete without any aesthetic alteration.

For many investors, asset protection is just as important as the asset itself. When Macklowe Properties set out to develop the tallest residential building in the Western Hemisphere, protecting it became a top priority.

Macklowe commissioned WJE (Wiss, Janney, and Elstner Associates) and Simpson Gumpertz & Heger to find the right solution; To provide years of protection against weather and the natural elements that contribute to concrete erosion. Silanes are known for this type of protection, but traditional liquid silanes have low viscosity and do not penetrate deep enough into high density concrete or vertical surfaces.

By using Iso-Tek™ 8501, you can protect vertical high density concrete and achieve deep penetration without loss of material.

Here’s why Macklowe selected Iso-Tek™ 8501 to protect 432 Park Avenue located in New York City:

432 Park Avenue Photo

A Penetration Predicament

Consumption is directly related to time of contact. Penetration depth of silane is dependent on porosity, time of contact, and degree of saturation.*

For silanes to work effectively, they must be absorbed deep into the substrate where they react with silica in the concrete. The deeper the silanes penetrate, the better protection they can provide. Instead of experiencing excessive material loss, vertical run-off, and shallow penetration levels with traditional liquid silanes, Iso-Tek 8501™ high-viscosity gel sealer defies gravity to deliver astounding absorption.

* A. Johansson, M. Janz, J. Silfwerbrand & J. Trägårdh; Swedish Cement and Concrete Research Institute, Stockholm, Sweden

Penetration Depth
in Carbonated Concrete Cubes

Showing greater absorption in high-density (lower water-to-cement ratio) concrete

0 2 4 6 8 12 10 14 16 18 PENETRATION DEPTH (mm) Liquid “pure” silane Iso-Tek 8501 Solvent-based silane (30% active content) Solvent-based siloxane Water-based silane (40% active content) in g/m 3 100 250 400 100 250 400 100 250 400 100 250 400 100 250 400 W/C = 0.70 W/C = 0.45

Concrete Results

"An ounce of prevention is worth a pound of cure."

In the 5 years since 432 Park Ave was treated, moisture level readings have varied between 3-4%. No visual or structural defects are known and micro-cracking remains well below expected.

There’s real power in knowing which sealer performs best, especially when the materials used on a project push the boundaries of construction. When you can see which sealer provides the best protection, you can use that insight to make the best investment for the future.

Iso-Tek™ 8501 was designed for high-density vertical concrete and continues to outperform when put to the test.

Ready to use Iso-Tek™ 8501 on your project?

Iso-Tek 8501 on palettes

Iso-Tek 8501

A gel based specialty sealer for high-density concrete. This aqueous silane-based sealer dramatically reduces moisture absorption, chloride-ion ingress, sulfates, acidic gases, salts and water intrusion inhibiting corrosion.

Projects trusting Iso-Tek 8501: