Frequently Asked Questions

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• How do you fasten the baseboard in a NUDURA house?

  The best way is to rip a plywood strip 2 to 2 1/2" wide and screw it in place to the webs along all the walls. Fasten these strips at every fourth web. Now the drywall contractors can set their drywall on top of it, and will cut their top sheets accordingly to suit this height. The result is you have full wood fastening for nails along the complete wall surface and the plywood is guaranteed to be covered by the baseboard.

• How do you fasten a typical 1104 type box to the walls?

  Our form panel thickness is 2 5/8”. This is deep enough to accommodate almost every standard depth electrical box. Deeper boxes are easily accommodated by simply gluing a square of foam on the inside of the form at the location being planned for the box during the pre-pour phase of the installation process. 

• How do you attach siding, drywall or other finishes to NUDURA ICF?

  The NUDURA form unit has a fastening strip located every 8” (200mm) on centre. These fastening strips are continuous up the full height of the form unit, and have a patented mechanism that interlocks one fastening strip to the one below it or above it. These fastening strips are indicated on the surface of the form by a diamond pattern. They are 1 ½” wide and have a higher pull out strength than a dimensional stud. Different types of cladding will have different installation procedures.
  
  

• What type of screws do I use to fasten vinyl siding?

  A standard #6 x 1 ½”  to 1 ¾” coarse thread “bugle” style or “flute” head (1/4” dia. head) zinc coated or otherwise non-corrosive screw  will do nicely (NOTE: as inexpensive as they are - drywall screws with the black sulphur coating will eventually corrode).

  
  Equally as useful are standard bright (chrome like) finish #6 or # dia. x 1 12” pan head coarse thread self-tapping screws. These have the added bonus of being able to be used for a multitude of anchorage purposes besides siding fastening and do not corrode as easily as drywall screws.

• Where should I make my cuts in a form unit to achieve the desired length of wall?

  To achieve your desire length of wall, you will have to use standard form units, corner form units, and then remove certain lengths off each of these to get the desired length of wall. The form is designed to make measuring as easy as possible for the installer. Each interlock along the top and bottom of the form is 1”, and the score line on the outside of the form panel denote 2”. By knowing that the webs are 8” apart, you can use these three units on the form to find where you need to make your cut.

• What R Value can I get from a NUDURA ICF wall?

  The aggregate R Value of a NUDURA ICF Wall, with concrete and gypsum board interior finish in place, is 22.4. We state this as a standard value across all thickness of form unit as the thermal resistance of concrete is nearly negligible. The actual R Value would have to be determined from the overall performance of the wall as a system. A performance R Value which is based on energy savings and studies of thermal resistance of an ICF wall shows that a wall of R50 is not at all uncommon.

• How does one convert from R Value to RSI or vice versa?

  To convert R Value to RSI, use the following equation:

   R1  = .176 RSI . Therefore- to convert R Value to RSI, simply divide the R Value by the inverse (5.685)

   

  Ex) R14= ???RSI

       RSI= 14/ (1 /.176)

       RSI= 14/5.685

       RSI= 2.46

• Can I use nails to fasten finishes to NUDURA form units?

  USE SCREWS- NOT NAILS. Pull testing of fasteners into polypropylene has determined that the most assured fastening for resisting required loading as noted in local building codes are screws – a #6 self tapping screw into NUDURA fastening strips can provide an ultimate pullout holding capability of approx. 222 lbs of force.

   

  In addition, use a power driver with the torque set to the lowest possible setting. Your objective is to stop driving the siding BEFORE it begins to dimple into the foam. You want the siding to slide loose so that it can expand and contract in the sun. Remember, it hangs from the screws rather than being anchored firmly by them to the surface of the

• How can I prevent termites from nesting and infesting the foam?

  NUDURA has found the peel and stick waterproofing membrane/ termite barriers to be the most cost effective. The “XT” Membrane System by Polyguard is among the most well known termite barriers and can be obtained through their distribution by contacting:

  Polyguard Products, Inc. Polyguard website.
  

  
  Additionally, NUDURA can provide detailing to your NUDURA Trained Installer to enable treatment of the grade level of the form system with a feature called an “inspection strip”. This is a specially cut horizontal band that reveals the concrete in the cavity directly to the outside, preventing any termite from being able to access the foam at grade or get to it without first being ejected to grade at the outside. The presence of termites will then be visible as they create a mud ‘shelter tube’ to get back below grade.

• Are there any VOC’s or gaseous emissions from the foam block?

  In our NUDURA Insulated Concrete Forms, the webs are composed of high-density polypropylene, made from 100% post-consumer recycled plastic. This plastic is totally inert and emits nothing. Copies of the MSDS sheets for the virgin version of this material are available from either NUDURA’s Technical Service Department, or your local distributor.