Materials:(Tomtar) Knudson KR-12

Jump to: navigation, search

Materials:(Tomtar) Knudson KR-12

Division C - Accepted Materials

Knudson KR-12
by TRS Building Envelope (Tomtar Roofing and Sheet Metal Ltd.)

The metal panel listed and described below is accepted for use in the RoofStar Guarantee Program.
Tomtar Roofing & Sheet Metal Ltd.
Contact Address
See the current Membership list and contact information at
Product Group - Standing Seam Metal Roof System
Panel Machine
Knudson KR-12
Panel Name
Tomtar (Knudson) KR-12 Standing Seam panel
Seam Type
Standing Seam (38 mm (1-1/2"))

The roofing assembly / material information published below and in the RCABC Roofing Practices Manual DOES NOT represent a complete set of the manufacturer's published data, nor does it represent a detailed specification. The preparation of a detailed specification is the responsibility of the design authority. For more information about this product or system, consult the manufacturer.


The Knudson KR-12 is an on-site continuous panel metal roofing machine. Panel profiles vary from 300 mm (12") to 500 mm (20") wide with a seam height of 38 mm (1.5").

On-site roll forming provides for the elimination of end laps with continuous panel forming capabilities in lengths up to nominal 46 m (150').


  1. General: Standing seam panels employ a hidden fastening system for securement to a solid substrate. Panels are seamed together with a mechanical seamer.
  2. Range of application: on wood or metal sloped roofs; in commercial, institutional, industrial and residential construction; for re-roofing or new construction.
  3. Fasteners (Screws):
    1. For panel clip to steel attachment to be No. 12-16 by 22 mm (1") long self- drilling, self-tapping, hex-washer head plated steel screws used without sealing washers. Two fasteners per panel clip used, inserted into panel clip guide holes.
  4. Clips:
    1. Two part assembly consisting of a No. 16 MSG min thick coated steel base approximately 47.6 mm (1-7/8") wide and 40.9 mm (1-5/8") long and a No. 22 MSG min thick coated steel upper tab section. Fastened 600 mm (24") on centre. Height 61 mm (2-7/16") min, 75 mm (3") max, width 108 mm (4-5/16"); Knudson Manufacturing Inc. KR-24 Low-Floating Clip, KR-24 High-Floating Clip, or
    2. One part assembly, No. 22 MSG min coated steel. Height, 59 mm (2-3/8") min, 75 mm (3") max, width 75 mm (3"); Knudson Manufacturing Inc. KR-24 Low-Fixed Clip, KR-24 High-Fixed Clip, fastened 600 mm (24") on centre.
  5. Deck Requirements: in keeping with the Standard for Architectural Sheet Metal (ASM) Systems.






  1. Minimum roof slope is 1:6 (2" in 12"). Severe conditions (heavy snow or ice) minimum slope is 1:1.5 (8" in 12").


  1. Wind Uplift Resistance: Panel securement shall conform to the requirements in Part 3 of the Standard for Architectural Sheet Metal (ASM) Systems.
  2. Materials:RoofStar (RGC) accepted metal panel systems shall be formed of steel conforming to the requirements published in Section 9.2. of the Standard.

Back to Site-Formed Metal Roofing Systems

Back to Accepted Materials