Frequently Asked Questions:

TYPICAL QUESTIONS ABOUT SHEATHING

Q: What adhesive is used for Gypsum Sheathing?
A: 121, 121 Dry, 302, 395A Liquid membrane Adhesive, and 303 can be used for Gypsum Sheathing.

Q: What adhesive can be used with masonry type substrates?
A: 121, 121 Dry, and Parflex 304. These are all cementitious.

TYPICAL QUESTIONS ABOUT COATINGS & FINISHES

Q: Can Parex coating be applied directly to Dens-Glass Gold?
A: Parex coating can be directly applied to a sheltered soffit area. Direct application to Dens-Glass Gold as a primary wall cladding is not approved other than for specific exceptions.

Q: What colors can safely be used over (EPS) insulation board?
A: Parex recommends color choices with a light reflectance value of 30% or greater be used on (EPS) insulation board. For darker application, consult Parex Technical Services for further options.

TYPICAL QUESTIONS ABOUT PRIMER

Q: What benefits are there when primer is used?
A:

1. consistent and bright colors
2. reduced absorptiveness of the base coat for longer open time to float finishes
3. provides a sealer over the base coat and reduces the chance of efflorescence bleed
4. improves the coverage of the finish.

Q: What primer is required to use with Parex Cerastone 630?
A: Parex requires using Parex Sanded Primer 313 or Primer 310.

Q: Is there a color variation if you compare finish over primed vs. unprimed applications?
A: Yes

TYPICAL QUESTIONS ABOUT EXPANSION JOINTS

Q: Where should continuous expansion joints be installed?
A: continuous expansion joints should be installed in the following locations:

1. At building expansion joints.
2. At substrate expansion joints.
3. At floor lines in wood framed construction.
4. Where the Standard System abut one another.
5. Where the Standard System abut other materials.
6. Where significant structural movement occurs, such as:
   1. Changes in roofline.
   2. Changes in building shape and / or structural system.
7. Where the substrate changes.

SUBSTRATE MOVEMENT AND EXPANSION AND CONTRACTION OF THE SYSTEM AND ADJACENT MATERIALS SHALL BE TAKEN INTO ACCOUNT IN THE DESIGN OF EXPANSION JOINTS, WITH PROPER CONSIDERATION GIVEN TO SEALANT PROPERTIES, INSTALLATION CONDITIONS, TEMPERATURE RANGE, THERMAL COEFFICIENTS OF MATERIALS, JOINT WIDTH TO DEPTH RATIOS, AND OTHER MATERIAL FACTORS.

Q: Does Parex require an expansion joint at all floor lines?
A: At wood framed buildings only. Unless there is a Web Truss floor joist, wood l-beam Truss- joint type, or Laminated Veneer Lumber floor joist, then there is no expansion joint needed.

Q: What is the minimum space required for expansion joints?
A: Parex recommends a minimum gap of ³/₄" for expansion joints unless otherwise specified by the architect.

TYPICAL QUESTIONS ABOUT INSULATION BOARD

Q: What is the maximum thickness of EPS insulation board that can be used for Parex PB EIFS?
A: 4 inches is the maximum thickness of EPS insulation board to be used for Parex PB EIF system. Some codes allow thicker foam if tested. Contact Parex Technical Services for further information on the use of thicker EPS.

Q: What is the minimum thickness of EPS insulation board that can be used for PB EIFS?
A: ³/₄ inch is the minimum thickness of EPS insulation board to be used for a PB EIF system. Parex recommends using at least 1 inch of insulation board.

Q: Can XPS insulation board be adhesively attached?
A: Yes. XPS sanded or rasped insulation board can be adhesively attached with I-C One Base Coat 308, but only to concrete, masonry and stucco surfaces. However, the adhesive attachment must be supplemented by mechanical fasteners, typically 4 per 2' x 8' sheet of XPS.

Q: What is the minimum thickness of EPS that can be mechanically fastened?
A: 1-¹/₂ inches is the minimum thickness of insulation board that can be mechanically attached.

How big of a gap should be filled after insulation board is attached and what should be used?
A: Any gaps in insulation board greater than ³/₃₂" should be filled with slivers of insulation board or Polyurethane Spray Foam. Don't use latex spray foam.

Q: If EPS insulation board stays in the sun for a long period of time and yellowing occurs, what should be done?
A: The EPS insulation board should be rasped down until yellowing is removed. Make sure that there is at least ³/₄" of insulation board remaining after the rasping is done.

Q: How do we check for the quality of the EPS in the field?
A: To test the EPS board, break a small piece in half and smell immediately. The board should not be used if there is a noticeable solvent odor.

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TYPICAL QUESTIONS ABOUT PAREX SYSTEMS

Q: What type of systems does Parex have to offer?
A:
Standard System
Premium System
Standard Extra System
I-C Gold System
I-C Silver System
Water Master Residential Systems
Water Master Commercial Systems
Water Master with StuccoWrap

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TYPICAL QUESTIONS ABOUT MECHANICAL FASTENERS

Q: What type of fasteners does Parex require for mechanically fastening insulation board to a substrate?
A: Parex recommends using Wind-Lock's Wind-Devil 2 Mechanical Fasteners for EPS and Wind-Lock U.L.P. Plates for XPS.

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TYPICAL QUESTIONS ABOUT CEMENTITIOUS BASE COATS/ADHESIVES

Q: What causes efflorescence in cementitious base coats?
A: A combination of circumstances causes efflorescence. First, there must be soluble salts in the material. Second, there must be moisture to pick up the soluble salts and carry them to the surface. Third, evaporation or hydrostatic pressure must cause the solution to move. If any one of these conditions is eliminated efflorescence will not occur.

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TYPICAL QUESTIONS ON SEALANTS

Q: What kind of sealant does Parex recommend?
A: Parex recommends an ultra-low modulus sealant that is capable of 100% elongation and 50% compression.

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TYPICAL QUESTIONS ON REINFORCING MESH

Q: What are the classifications and impact ranges established for Class PB EIFS?
A:
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TYPICAL QUESTIONS ON TERMINATIONS

What are the ways that an EIF system can be terminated?
A: There are 4 ways to terminate a Parex EIF System:

1. Back wrapping
2. Edge wrapping
3. Parex Track
4. Seal Tape

Q: What is back wrapping?
A: Backwrapping is the traditional method of encapsulating the insulation board edge. Back wrapping simply means that the insulation board is wrapped in fabric reinforced base coat at edges at terminations and that the mesh extends behind the insulation board at least 2¹/₂". Edgewrapping means that mesh reinforced base coat extends over the edges of insulation at terminations and onto the framing or masonry.

Q: What is Parex Track used for?
A: Parex Track is used in many locations as an alternative to backwrapping. Although it cannot be used in every situation, it provides a convenient alternative to backwrapping, and is a time saving accessory to applicators.

Q: Where is Parex seal tape used for terminating an EIF system?
A: Parex seal tape is used exclusively for perimeter seals around windows and doors, penetrations, or in abutting insulation board to dissimilar materials.

Q: How high should the EIF system be terminated above grade, pavement and rooflines?
A: The EIF system should be terminated above pavement and above rooflines a minimum of 2 inches. The system should be terminated a minimum of 6 inches above grade at un-paved areas.

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TYPICAL QUESTIONS ON COATINGS

Q: What product does Parex recommend to recoat a Parex finish?
A: Parex recommends using Recoat Gel 314 to recoat Parex finishes without changing the texture of the finish.

Q: What are some key point to know regarding Recoat Gel 314?
A: Recoat Gel 314 is semi-opaque and tints differently than other coatings. It can only be tinted at plant locations. Dark colors are difficult to tint. Parex may decide not to tint them or not warrant subsequent matching to previous batches.

Q: Can you use Recoat Gel 315 to change the color of the finish?
A: Yes. You can recoat the finish with the same color or a darker color but you can't change from a darker color to a lighter color.

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