HardieWrap™ Flashing FAQ

Why should I choose butyl rubber adhesive over asphalt?

Butyl rubber adhesive is more reliable than asphalt.
  • Butyl is pliable at low temperatures and can be applied to a variety of building materials at temperatures 30°F to 180°F. Asphalt becomes brittle below 40°F, reducing the ability to stick to surfaces.
  • Butyl has high cohesive strength and structural integrity that support the adhesive at elevated temperatures as high as 200°F. SBS asphalt has a narrow temperature range and often will ooze at elevated temperatures.
  • Butyl rubber adhesive contains no asphalts, VOCs (volatile organic compounds) or solvents. SBS asphalts can react with the solvents in caulk and sealant compounds, causing degradation of both products, which compromises the seal integrity reducing water resistance.

Can I use asphalt flashing with the HardieWrap™ weather barrier?

Yes, but we recommend butyl for the reasons given above.

When should I use HardieWrap™ Flashing and when should I use HardieWrap™ Flex Flashing?

HardieWrap Flashing should be used on windows and doors with straight edges. HardieWrap Flex Flashing should be used on the sill pan and custom windows or doors.

Does HardieWrap Flashing and HardieWrap Flex Flashing self-seal around fasteners?

Yes. HardieWrap Flashing and HardieWrap Flex Flashing self-seal around fasteners and are self-adhering butyl flashings which are easy to install by peel and stick application. Additional fasteners are not necessary.

What sizes do HardieWrap Flashing and HardieWrap Flex Flashing come in?

HardieWrap Flashing is available in 4", 6" or 9" widths, and are 75' long; HardieWrap Flex Flashing in 6" or 9" widths and 75' long.

How well does HardieWrap Flashing and HardieWrap Flex Flashing stick to OSB?

HardieWrap Flashing and HardieWrap Flex Flashing adheres to OSB, provided the surface is dry, clean and free of waxes or oils. Because most OSB is dusty and waxy on the job site, we recommend – but do not require – that a primer adhesive be applied to the surface of the OSB to improve adhesion for the flashing to bond to. Refer to the HardieWrap Flashing Guide for further information about primers.

Are additional fasteners necessary to supplement flashing adhesion?

Fasteners are not required to “tack" up either HardieWrap Flashing or HardieWrap Flex Flashing. The slow tack adhesion allows for easier installation because the flashing can be repositioned without tearing the surface of the housewrap. The adhesive strength of butyl rubber becomes stronger over time and reaches full-cure in 24 hours.

How are HardieWrap Flashing and HardieWrap Flex Flashing packaged?

HardieWrap Flashing comes in individually shrink-wrapped rolls and HardieWrap Flex Flashing comes in a convenient dispenser box.

Where should HardieWrap Flashing be used?

HardieWrap Flashing is ideal for the windows, doors and utility penetrations. See the HardieWrap Flashing Guide for further details.

How long can HardieWrap Flashing and HardieWrap Flex Flashing be exposed to the environment before siding is installed?

HardieWrap Flashing and HardieWrap Flex Flashing have a UV stability of up to 180 days (6 months).

What types of siding can HardieWrap Flashing and HardieWrap Flex Flashing be used under?

  1. HardieWrap flashings can be used behind any code-compliant cladding assembly, but there exists industry best practices for some claddings, such as stucco, which require specific methods of applications which should be followed for best performance.
  2. When installing HardieWrap™ weather barrier, follow the recommendations of the local building codes and the HardieWrap Installation Requirements. For installation instructions, please go to www.hardiewrap.com.

When will HardieWrap Flashing and HardieWrap Flex Flashing be available in my area?

It is available in Georgia, North Carolina and South Carolina, with other states to follow shortly. Contact your James Hardie Sales Representative or call James Hardie Customer Service at 1-866-4-HARDIE (1-866-442-7343) for more information.

What size flashing should I use for 2x4 and 2x6 timber construction?

For 2x4 construction, use 4" or 6" HardieWrap Flashing along with 6" HardieWrap Flex Flashing for the sill pans. For 2x6 construction, use 9" HardieWrap Flashing and 9" HardieWrap Flex Flashing.

Can I use HardieWrap™ Seam Tape in place of HardieWrap Flashing or HardieWrap Flex Flashing?

No. HardieWrap Seam Tape is specifically designed for sealing vertical and horizontal seams and small tears; it should be used when adhering HardieWrap to other materials, e.g. vinyl or aluminum window flanges.

Can I use HardieWrap flashings with other housewrap?

Yes. HardieWrap flashings are compatible with major brands of housewrap, building paper and OSB sheathing, providing they are free from excess dirt and residue.

Can I use asphalt-based flashings with HardieWrap flashings?

Yes. But we don't recommend asphalt-based flashings because they are more likely to degrade over time, reducing their resistance to water infiltration.

Where can I get more information about HardieWrap flashing installation?

Installation instructions can be found at www.hardiewrap.com. You can also contact your James Hardie Sales Representative to find an Installation Specialist in your area or call James Hardie Customer Service at 1-866-4-HARDIE (1-866-442-7343).

What is the warranty?

HardieWrap weather barrier, HardieWrap Flashing, HardieWrap Flex Flashing and HardieWrap Seam Tape all have a 10-year limited transferable product warranty.

What is the advantage of using all HardieWrap products together?

Together, they form the HardieWrap™ weather barrier solution. HardieWrap weather barrier, HardieWrap Flashing, HardieWrap Flex Flashing and HardieWrap Seam Tape work with the cladding to form an important part of a home's weather protection envelope.