Structural Skin

Structural Skin is a fiber reinforced surface bonding cement which can be applied directly to the substrate or in combination with metal lath to a thickness of 1/8″ to 1/4″.

Where to use:

Base coating for exterior wall systems over block, concrete, brick, exterior sheathing and plywood.

How to apply:

Structural Skin can be troweled or machine applied.  Most carousel and rotor stator pumps are capable of spraying Structural Skin.

Performance Characteristics

  • Waterproof barrier Passes ASTM E514.
  • Anti-carbonation barrier Mitigates carbonation of concrete.
  • Durable Resistant to weathering action, excellent freeze/thaw stability and abrasion resistance.
  • Breathability Allows moisture to diffuse, preventing damage from moisture build-up in wall system.
  • Structural When applied to both sides of dry stacked concrete block, forms a structural wall system. IBC approved.
  • Smooth finish Ready for roller, spray and trowel applied decorative coatings such as Conpro Lastic or Conpro Color Coat.

Surface Preparation

  • Remove loose and deteriorated material, laitance, dirt, dust, oil and any surface contaminants that will inhibit proper bond.
  • Repair spalled areas, static cracks and voids with Conpro Set or Structural Skin.
  • Substrate should have open-pored and textured surface.
  • Apply Conpro Start where a consolidant is of benefit.
  • Saturate substrate with clean water, (saturated surface dry/SSD). Wall should be wet when Structural Skin is applied.
  • For best results on concrete grind or abrasive blast (CSP 3). Refer to ICRI Surface Preparation Guide 03732 for information about Concrete Surface Preparation (CSP).
  • Refer to Conproco Exterior Wall Systems literature for preparation over substrates other than concrete and concrete block.


  • No priming is required under normal circumstances.


  • Mechanically mix using a low speed drill (400 – 600 rpm) and mixing paddle or mortar mixer.
  • Pour 5 quarts of potable water into a clean mixing vessel and slowly add all of the powder.
  • Mix continuously for 3 minutes to a uniform, lump-free consistency.
  • Add up to 1 pint of additional water if needed.
  • Allow to “breathe” for 1 minute and remix for 1 minute. This will improve workability and open time.
  • Do not over mix, as this will entrain air and cause damage to the glass fibers.


Mortarless concrete block wall system

  • At the time of application, surfaces should be saturated surface dry (SSD) but hold no standing water.
  • Concrete block must be butt tight and wall plumb and level.
  • Trowel or spray apply material to a uniform minimum of 1/8 inch.
  • Apply with a vertical motion and finish with a horizontal motion.
  • Material must be applied so that both sides of the wall have a uniform, continuous 1/8 inch coating.

Conproco Impact Wall System (existing block, brick and concrete)

  • At the time of application, surfaces should be saturated surface dry (SSD) but hold no standing water.
  • Add 1 quart of K-88 Admix (replacing 1 quart water) per bag of material.
  • The proper mix ratio is 5 parts powder to 1 part water to ¼ parts K-88 Admix.
  • Trowel or spray apply material to a uniform minimum of 1/8 inch.
  • Apply additional coat at 1/16 – 1/8 inch to achieve a level plane where desirable.
  • Trowel on with a vertical motion and finish with a horizontal motion.

Conproco Impact RM Wall System (reinforced metal lath)

  • Plywood and OSB must be APA Exterior rated and be firmly attached to substrate in accordance with applicable building codes.
  • Masonry and concrete walls must be structurally sound.
  • Place trim accessories (expansion joints, corner bead, etc.) as specified.
  • Mechanically fasten self-furring diamond mesh metal lath (complying with ASTM C841 and ASTM  C847)  within  the  confines of the panels created by the trim accessories. Make sure to overlap the flanges of the trim accessories.
  • Add 2 quarts of K-88 Admix (replacing 2 quarts water) per bag of material.
  • Trowel or spray apply material to a uniform minimum of 3/16 inch, to completely cover the lath.


  • Keep damp with a fine mist of water for 24 hours.
  • Protect from direct sunlight, wind, rain and frost during curing period.

Clean Up

  • Clean tools and equipment with water immediately after use.
  • Cured material must be removed mechanically.


  • 45 ft.²/50 lbs. @ 1/8 inch.

Product Handling


  • 50 lbs. paper bags.

Shelf Life

  • 12 months when properly stored.


  • Transport and store in cool, clean, dry conditions in unopened containers.
  • High temperature or high humidity will reduce shelf life.


  • Do not apply unless substrate and ambient temperature can be maintained at a minimum of 40°F for 24 hours. Refer to ACI Cold Weather Application Guidelines.
  • Cold mixing water and low temperature will retard set. Hot water and high temperature will accelerate set.
  • Protect application from precipitation and high wind for at least 8 hours.
  • Do not add more water than specified.
  • Do not re-temper as this will damage the fiber glass reinforcing.
  • Avoid overworking material during placement.
  • Over mixing will cause damage to the fiber glass reinforcing.

Health and Safety

  • Product is alkaline.
  • Do not ingest.
  • Avoid breathing dust.
  • Avoid contact with skin and eyes.
  • Refer to Safety Data Sheet (SDS) for additional information.

First Aid

  • In case of skin contact, wash thoroughly with soap and water.
  • For eye contact, flush immediately with a high volume of water for at least 15 minutes and contact a medical professional.
  • For respiratory problems, remove person to fresh air.


  • Dispose of material in accordance with local, state and federal regulations.