GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

New fastener for applying exterior mineral wool.

albertrooks | Posted in Green Building Techniques on

We have been working with Fastenmaster in an effort to create a US made screw for applying Mineral Wool that sets in one motion and does not compress the MW. Therefore eliminating the need for “squash blocks” and making application quick while leaving the battens in plane. We have had some success and have a model built for 3″ MW. A small production run has been made in the few thousand pcs range.

We are looking for feedback and confirmation that this fastener works for others. Are there any of my fellow “rock-heads” out there who regularly use MW and could test a small section of wall? This size only works on 3″. It does not work for 2″ or 4″.

If we continue to find that this method works, we can go forward with a wider variety of lengths for varying thicknesses with confidence. If you are interested in testing the 3″ version on a section or full project, please send an email to: info[at]smallplanetworkshop[dot]com with your contact and we will get in contact with you.

Happy Holidays!

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. Mike Eliason | | #1


    will this be available in a stainless steel option, or just epoxy coated? congrats! more u.s. innovation to catch up to the europeans is a phenomenal feat!

  2. albertrooks | | #2


    So far just in steel epoxy coated. SS is possible. lets see if it works for more than just me!

  3. propeller | | #3

    Thanks Albert,
    I had dropped the idea of using mineral wood outside due to the complexity of the installation. I'll reconsider it now. Do I understand that someone is to drive these screws through regular wood strapping (1X3 or 1X4)?

  4. jklingel | | #4

    Will these work better w/ 1" fender washers under the head? Plastic ones could be pre-installed at the factory, like the cap nails. ???

  5. kevin_in_denver | | #5

    Response to Marc,
    I'm pretty sure that the sheathing or strapping goes up after all the mineral wool is in place. It would be too hard to hold up the insulation and a board at the same time you are driving a screw.

  6. albertrooks | | #6

    Kevin/John: Yes, it's just to hold the siding up via the battens. A quick way to keep them in plane so the siding is flat and not wavy. It's not to help hang the MW, only the batten after the fact.

    Marc: You got it. Drive the screw through the strapping (or batten) through the MW, WRB, sheathing, and into the framing.

  7. albertrooks | | #7

    Moving it back to the top in case it missed any other "rock heads" out there playing with mineral wool applications.

    Happy new year!

  8. user-757117 | | #8

    I would be very interested in giving them a try except that I haven't got anywhere where 3" MW would be appropriate.

    Out of curiosity, have you considered what other "sizes" you might be stocking?

  9. Mike Eliason | | #9

    3" works great for us, as this is the assembly we'd like to be spec'ing for our PH projects from here on out.

    but yes, any in the 6-10" range for CLT application?

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |