Contact NUDURA by phone or email


Welcome to the Frequently Asked Questions blog by NUDURA Insulated Concrete Forms. Here is a great spot to review and be part of the conversations on FAQs about NUDURA ICFs. Be sure to check back regularly!

Managing Moisture with NUDURA ICFs

by NUDURA Blogger | Jan 23, 2017

According to ASTM E96, a material must not exceed 45 ng/Paּsּm² to qualify as a vapor barrier. This unit denotes the ‘permeance’ of the material, or how much moisture per force applied (air pressure), in a second over a square area. NUDURA Type II EPS qualifies as a vapour barrier with a permeance value of 36 ng/Paּsּm².

Although the joints between the NUDURA form units are tight, below grade waterproofing is still necessary. We sell a peel and stick waterproofing that is easy to apply and carries a two-year warranty. This membrane must cover the foundation walls. In situations where there is an attached garage, the below grade wall shared with the basement must be covered, and a 4 foot (1200mm) overlap to the adjacent walls.

Naturally, one of the main purposes of applying a vapor barrier and waterproofing is to prevent moisture damage, as well as mold and mildew growth. EPS has no active properties, which means it is very slow in any reaction. However, it does not mean that mold will never propagate on an ICF wall just because it uses EPS as insulation.

The truth is that without sufficient airflow, excess moisture can accumulate via condensation at any openings. If not evaporated, this build-up will eventually cause mold to grow on the paper of the drywall.

Part of a great ICF installation is adjusting your HVAC system for a tighter building envelope, which will require more air exchanges.

To learn more from our knowledgeable technical services team, please click here to contact us or call 866-468-6299.


Leave a comment
  1. Alina Archibald | Mar 16, 2019

    After completing the installation of the roof and windows, we noticed that we have leaks in the walls. What to do if we have voids in the concrete?

    Thank you

    Thank you for bringing this concern to our attention. The performance and safety of each and every Nudura ICF home is paramount. Our Distributor’s are always available for convenient technical advice and resolving customer related concerns. To better serve you, perhaps more information is necessary to narrow down the source of the water migration. All components of the ICF system must be reviewed including that the installation techniques have been performed in a good workmanlike manner.

    Although we are unable to render an opinion with the information provided. We encourage you to provide pictures, drawings or details that should be reviewed by your distributor and/or the Nudura Technical Support Team. Please contact for additional assistance.

    NUDURA Blogger | March 18, 2019
  2. Alina Archibald | Dec 24, 2018

    We are in the process of building: the membrane has been attached, but it is peeling off.

    I believe the reason for it is that my contractor had tough time installing it, so it was ripped off the wall couple times and the same pieces were put back on.

    The parge coat has not yet been applied.

    1. What type of adhesive can i use to reattach the membrane? I can no longer replace the membrane as the backfill mostly completed. 

    2. Can i put a termination bar at the top of it?

    3. If i put the termination bar, will the parge coat stick to it?

    Thank you

    The portion of the membrane that is peeling off should be cut off at the point where it is still sticking to the wall and discarded. In these areas where the membrane has been applied and then taken off or peeled off, our membrane primer should be used over the wall surface in those areas prior to installing the new membrane. New membrane should be used and lapped a minimum of 6” over the membrane on the wall.

    A termination bar can be used at the top of the membrane however depending on the material the termination bar is made of (typically smooth plastic or metal) most likely the parge coat will not stick. The best recommendation would be to complete the membrane installation as described above with the primer and the new membrane, and then immediately complete the parge coat to seal the top edge of the membrane. If the parge coat cannot be completed immediately, an EPS compatible pointing mastic can be used along the top edge of the membrane to seal it to the EPS until such time that the parge coat can be completed.

    NUDURA Blogger | January 3, 2019
  3. David Wesley | Jul 22, 2018
    How do I fix a leak in a basement wall with ICF? The leak is very small but enough to ruin drywall. Our house was built 10 years ago.

    A leak in any basement wall can be caused by a number of conditions and that will change how to best solve the leak. A qualified foundation waterproofing contractor will need to review site conditions to determine how the water is entering the building and then can work out a plan to repair the issue. An ICF wall should be properly waterproofed with an EPS compatible peel and stick membrane, protection board, proper backfill material and good surface water control.

    - NUDURA Blogger July 23, 2018

    Leave a comment


      North America 866-468-6299 International +1 705-726-9499