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Community and Q&A

Furring strip screw recommendations

Nat_T | Posted in General Questions on

Assembly = 2″ zip R (1.5″ polyiso + osb) with 1x furring strips. If I were to go for 1.5″ penetration I need min of 4.25″ screws, I see that headlock says min of 2″ penetration so that would give me 4.75″. So it seems like I need a 4-1/2″ or 5″ screw.

Fastenmaster has headlock 4-1/2 inchers (1/4″ short but I think it’d be ok) but looks like they’ll run me about $0.33 each, given the qty required this hurts. Any recommendation for what others are using for this application/length?

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  1. Expert Member
  2. Expert Member
    BILL WICHERS | | #2

    GRK and Spax may have some other options for you too. I’d go with a torx head (Phillips is a pain to use for construction screws), but aside from that I have no specific recommendations for you.


  3. dfvellone | | #3

    Headlok are ideal for this installation. When I ordered mine for my wrap and strap I spoke directly with Fastenmaster and they advised to use a fastener long enough so that the threaded portion of the shank is completely buried in the studs so that no part of the threads bridges the distance between the stud and the furring strip. The threads are the compromised portion of the shank, so to speak, and don't have the tensile strength of the unthreaded portion.

  4. Expert Member
    Akos | | #4

    I use either roofing deck screws (used for fastening insulation down for flat roofs) or zinc coated drywall screws.

    Check your local suppliers, these come in long length and are significantly cheaper than the stuff at the box store. Drywall screws come in up to 6" length, the deck screws up to 8" are stock but I think they even come longer.

    They are also bugle head so they sit flush on the strapping and won't have issues with the siding sitting flat.

    1. algoodwin | | #9

      Can we nail the furring? For example with a timber framing nailer? Or is that bad practice? It seems around here with 1 1/4inch osb+foam everything is nailed

  5. Nat_T | | #5

    Thanks - I was curious if anyone had found any cheaper options. Looks like for my fairly modest house i'm in for about $750 in fasteners for the furring strips - wasn't expecting that one.

    1. Expert Member
      Akos | | #6

      Like I said earlier, roofing deck screws. Last I bought them, it somewhere around $0.10 each for 6" ones.

  6. Nat_T | | #7

    What kind of corrosion protection should I look for in this application.

    Stainless seem to run around $0.50/screw. I'm not seeing galvanized at these lengths.

    I found "big timber" brand which I've never heard of that come in around $0.15/screw and state "The Ceramic Coating provides 1200-hour corrosion resistance in both ACQ and salt spray conditions". That's about 1/2 the price of the headlok. Anyone familiar with the "1200 hour" testing and in general would a ceramic coating be sufficient here? The headlok don't specify the coating as far as I can tell.

    Akos - If you happen to have a brand/product handy could you post a link. $0.10 sounds good and i'm curious what material/finish you're using (galv or other).

    1. Expert Member
      Akos | | #8

      The screws are behind your siding. Unless you have salt spray, not enough water will make it in there for corrosion to be an issue. I doubt you'll find much galvanized, most are either ceramic or zinc coated, similar to patio deck screws.

      The roofing deck screws are similar to this (I don't remember the brand, but look similar enough):

      Check with your local roofing supplier for the brand available to you.

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