Frequently Asked Questions

Parex USA coatings can be directly applied to a weather protected or soffit areas. Direct application to Dens Glass Gold, National Gypsum e2XP™ Extended Exposure Sheathing, etc... as a primary wall cladding is not approved other than for specific exceptions.

Any Parex USA cementitious base coat, full synthetic base coat, sheathing adhesive, or Key-Coat or Weatherseal Trowel Grade adhesive can be used to adhere an approved gypsum sheathing.

Parex USA suggests using Wind-Lock Wind-Devil, Demand Products PB Fasteners, or ITW Buildex Gridmate with their manufacturer's specified screws for EPS. Please consult Wind-Lock Corp, Demand Products or ITW for the correct fastener sizes.

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 and hydrostatic pressure must cause the solution to move. If any one of these conditions is eliminated efflorescence will not occur.

Parex USA recommends an ultra-low modulus sealant with 50% compression and 100% elongation.

ClassificationImpact Range
Standard Impact Resistance25-49 inch-lbs
Medium Impact Resistance50-89-inch-lbs
High Impact Resistance90-150 Inch-lbs
Ultra-High Impact resistance150 Inch-lbs

Parex USA recommends using color choices with a light reflectance value of 30% or greater be used on (EPS) insulation board. For darker applications, consult the Parex USA Technical Department for further options.

The advantages of using Parex USA Primer are as followed; reduces the chance of efflorescence, enhances the appearance and uniformity of the finish, improves finish coverage and trowelability.


Yes, it is recommended to tint the primer to match the color of the finish.

No, Primer cannot be used as a paint. Long term weather exposure would affect the Primer. Parex USA recommends using a Parex USA DPR Coating.

No, Parex USA recommends applying a full synthetic basecoat/Adhesive over the swirl finishes first to fill the voids before re-coating with another finish.

There are three types of insulation board used for EIF Systems (XPS) Extruded insulation board, (EPS) Expanded insulation board and Polyisocyanurate insulation board.

EPS insulation board beads are expanded and molded XPS insulation boards are extruded. The R-Value for (XPS) is R-5 and the R-Value for (EPS) is 3.86. The polyisocyanurate insulation board surface maximum working temperature is > 200 degrees and the (EPS) insulation board surface temperature is 165 degrees.

¾" is the minimum thickness of EPS insulation board that can be at the base of reveals.

1½ inches is the minimum thickness of insulation board that can be mechanically attached.

Any gaps in insulation board greater than 3/32" should be filled with slivers of insulation board or polyurethane spray foam. Do not use latex spray foam.

The EPS insulation board should be rasped down until the yellowing is removed make sure that there is at least ¾" of insulation board is remaining after the rasping is done.

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.

In a building structure a joint between adjacent parts which allows for a safe and inconsequential relative movement of the parts caused by thermal variations or other conditions.

Yes. At wood framed buildings, unless there is a web Truss floor joist, wood I-beam Truss Joist type, or Laminated Veneer Lumber floor joist then there is no expansion joint needed. Also, at the underside of concrete floor slabs that have sliding stud connections for floor deflection.

Parex USA recommends a minimum gap of ¾" for expansion joints unless wider is specified by the architect, or a wider joint is in the substrate. Then the EIFS joint should be as wide.

A continuous expansion joint is an expansion joint that that continues between the two adjacent materials.

Continuous expansion joints should be installed in the following locations:
A) At building expansion joints.
B) At substrate expansion joints.
C) At floor lines in wood framed construction.
D) Where the Standard System abut one another.
E) Where the Standard System abut other materials.
F) Where significant structural movement occurs, such as:
     At the underside of concrete floor slabs that have sliding stud connections for floor deflection.
     Changes in roof line.
     Changes in building shape and / or structural system.
G) Where the substrate changes.

There are 3 ways to terminating a Parex USA EIF System:
Edge wrapping
Vented Track (At Foundation Terminations Only)

Backwrapping is the traditional method of encapsulating the insulation board edge. Back wrapping simply means that the insulation board edge is completely wrapped in fiberglass mesh reinforced base coat and the fiberglass mesh wraps in back of the insulation board at least 2 ½".

Edge wrapping is similar to backwrapping, but with one significant difference; on sheathed substrates, the fabric reinforced base coat not only seals the insulation board edge, but also wraps onto the edge of the masonry substrate or laps onto the framing.

The EIF System should be terminated above pavement 2" and above rooflines and balconies a minimum of 1 inch. The system should be terminated a minimum of 6 inches above grade at un-paved areas.