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Technical Data Sheet (TDS)

VPU-155 "S" Urethane Sealer

Urethane Concrete Sealer

Special features

  • Moisture barrier up to 8# or 85% RH
  • Use prior to PUK-455 or ULC-500

Product Description
STAUF VPU-155 Urethane Sealer is a pure urethane based sealer for professional flooring installation. It does not contain any solvents, water or other harmful materials. It is therefore ozone and environmentally safe, is certified as "very low emissions", and is certified "green". VPU-155 is uniquely developed to mitigate the moisture pressure from a humid sub floor to an acceptable level for flooring installation and to bridge minor cracks in the sub floor. VPU-155 spreads easily and creates a dust free and evenly absorbent surface ready for installation of flooring. It has superior coverage and dries very quickly.
Pre-Installation Checklist
A successful installation requires proper preparation of the sub floor. Read and understand all applicable guidelines and technical data sheets before installation. Follow industry standards and flooring manufacturer's recommendations for sub floor moisture content, design, layout and application of flooring materials. All slab constructions must meet the specific requirements of the floor covering to be installed.
Sub Floor Examination
Prior to installation, the sub floor must be checked according to applicable installation guidelines. It must be solid and sound, clean, free of chaps and anti-adherents, as well as resistant to pressure and tension. Check for missing or compromised vapor barriers and hydrostatic pressure. Perform RH or CaCl moisture tests following ASTM standards. Results of 99% RH or 25# CaCl could indicate that there is a higher moisture content in the slab than what tests can measure and there might be hydrostatic pressure and/or a compromised or missing vapor barrier.
Moisture content in concrete sub floors must be below 8#/24hrs/1,000 sq. ft. using the Calcium Chloride Test or less than 85% RH using the in-situ test per ASTM F1869 and F2170.

Sub Floor Preparation
The condition of the sub floor will determine which type of mechanical treatment is required (e.g. wire brushing, sanding, grinding or shot blasting). Dust, paint, curing compounds, sealers, residual adhesives or other surface pollutants MUST be removed by suitable means. Extent of sub floor preparation can only be determined at the site by the installer. Clean the surface with an industrial vacuum cleaner, tack or damp mop floor before application. Do not use sweeping compounds as most will contain oil or wax which will act as an anti-adherent and prevent primers, sealers, leveling compounds, coatings and/or adhesives from bonding to the concrete. Cracks and gaps must be treated prior to application of primers, sealers, leveling compounds, coatings and/or adhesives (for details see Technical Information #19 @
Installation Procedure
Shake before use and apply sealer undiluted with appropriate applicator. Make sure sealer is spread evenly. Do not exceed the maximum coverage. Higher temperatures will speed up the drying time.

Do not transport below 14 °F. Store dry and protect from freezing.

When using other than STAUF products in conjunction with STAUF primers, sealers, leveling compounds, or adhesives, STAUF denies any and all responsibility for any ensuing problems and/or damages without prior written authorization from STAUF.
Do not dilute primer/sealer or mix with other products.
In case of accident, injury, spill or exposure, see SDS sheet for information. Consult technical data sheet at for updated information.
Do not use on sub floors with a moisture reading above 8#/24hr./1,000 sq. ft. (Calcium Chloride Test) or 85% (RH with in-situ probe)

The foregoing representations are based on the results of our most current product and material testing within a controlled environment and are of a non-obligatory advisory nature only. As such, they do not constitute an express or implied warranty of any kind including the Warranty of Merchantability and/or Fitness for a Particular Purpose. Because we have no control over the actual quality of workmanship, materials used and worksite conditions, STAUF USA, LLC. will in no event be liable for any incidental and/or consequential damages. herefore, we strongly recommend that prior on-site testing be conducted to refer to and study the suitability of the product for the intended purpose. With the release of this technical information sheet all its prior versions become invalid. For warranty and warranty disclaimer information please see our Limited Lifetime Warranty @
General Features
  • moisture cured urethane
  • LEED qualified
  • dries in less than 2 hours
  • contains no water
  • contains no solvents
  • contains no VOC (calc. per CA Rule 1168)
  • nonflammable
  • ozone friendly
  • Freeze/thaw stable
Installation Features
  • very low odor
  • cleans with acetone
  • spreads easily
  • good penetration of sub floor
  • dries quickly
  • higher temp will shorten drying time
  • suppresses minor cracks in concrete slabs
Long Term Features
  • improves bonding of STAUF urethane based adhesives
  • moisture barrier up to 8# or 85% RH using XBL10
  • suitable for radiant heat systems
Approved Sub Floors
  • Concrete Slabs
  • Ceramic Tiles
  • Stone, Terrazzo
Approved Trowels and Spread Rate
  • Sealer: XBL10 (7/64"x5/64"): up to 80 SF/gal.
Drying Time
  • approx. 2 hours or until clear
Temperature Range during Installation
  • 50-90F
Relative Humidity Range during Installation
  • 30% - 80%
Packing Size
  • 2 gal. Plastic Jug
  • 75 per pallet
  • Brown
pH value of concrete
  • resistent up to 14
  • dry
Shelf Life
  • 12 Months in original, unopened container
Revision: 2017-07-20 14:57:38

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