Available finishes

  • Aluminum mill (A)
  • Bronze anodized (B)

Part numbers

  • QMSC-LAG A 0283 (mill)
  • QMSC-LAG B 0285 (black)
GreenSample GreenSample

Classic Comp Lag
Item Code: QMSC - LAG

The Classic Comp Lag uses our patented QBlock Elevated Water Seal Technology® to ensure a long, watertight life on composition/asphalt shingle roofs. The Classic Comp Lag is designed to install fast, with just a single lag bolt. It is backed by solid engineering and certified for strength and waterproofing. 25-year limited product warranty.


  • Patented Elevated Water Seal Technology®
  • Stainless steel hardware (included)
  • All-aluminum 12" x 12" flashing
  • Won't void roof manufacturer's warranty
  • 25-year warranty; 50-year expected life
  • Meets or exceeds roofing industry best practices
  • Available through leading distributors
  • Works with all leading racks
  • Fast, simple lag bolt installation
  • No shingle cutting
  • 100% IBC compliant
  • Product Patent Information
  • Made in USA

The 12 x 12-inch Classic Comp Lag flashing is designed to fit within a standard 5 to 5.625" course and the exposed course should be no greater than 5.75". If the exposure is greater than this, use the Classic Shake Mount as an alternative. There's no shingle cutting and no shingle distortion caused by trying to force a fit.

WARNING: Quick Mount PV products are NOT designed for and should NOT be used to anchor fall protection equipment.

Product Resources

The QBlock Elevated Water Seal Technology®

Installation Guide (PDF 1.1MK)
Engineering report (PDF 1.6M)

Rail Compatability Engineering Reports

CAD drawing
DWG (726K) • PDF (63K)
Prepping for PV: Installing and Flashing
PV Roof Mounts

 article by Johan Alfsen, Director of Training
 Home Power, Aug/Sep 2011 (PDF 1.6M)

Product Specifications

Each mount kit (12 per box) includes:

  • Cast aluminum mounting block (2-1/4" L x 1-1/4" W x 1-1/4" H) bonded with .05" thick, 12" x 12" aluminum flashing
  • EPDM sealing plug, 5/16" x 7/8"
  • Hex-head lag screw, 5/16" x 5-1/2"
  • Fender washer, 5/16" x 1-1/4"

Flashing size 12" x 12"
Pullout/shear 2197 lbs. average ultimate pullout (Douglas fir); 1578 lbs. average ultimate shear
Tools needed for installation
  • Tape measure
  • Roofer's bar/shingle ripper
  • Chalk line
  • Stud finder
  • Caulking gun
  • Sealant compatible with roofing materials
  • Drill with 7/32" long-style bit
  • Drill or impact gun with 1/2" socket
Applicable roof types Standard and high-definition composition/asphalt and wood shingle roofs with 5" to 5-5/8" courses
Available finish
  • Aluminum mill
  • Bronze Anodized
Compatible racks
"When I'm punching dozens of holes to mount a solar array, I need to be certain there are no points of failure. Only Quick Mount gives me that assurance."
Tony Diaz, Century Roof & Solar
"I learned the hard way at a previous employer. Now I trust every job I can to Quick Mount PV. "
Justin McComas, Baker Electric Solar
"With our severe Rocky Mountain winters, only Quick Mount PV delivers the installation speed and absolute confidence we need."
Will Serene, Independent Power Systems
"We all agreed that only Quick Mount PV could give us the confidence we needed in mounting a big job like this."
Andy Tyson, Creative Energies
"Quick Mounts are better quality, more cost effective, and easier to install than any brand we've used."
Darren Malvin, American Solar
"I've been a roofer for 30 years and I know quality when I see it. Quick Mounts are the real deal."
Mark Fambrini, Mark Fambrini Renovations
"Thanks to Quick Mount PV, the alliance between roofing and solar is stronger than ever."
Chip Upshaw, Fidelity Roof
"I've tried a lot of attachment options, but here in the rainy Pacific Northwest, there is only one product I can trust on my customers' homes. Once we started using Quick Mounts we never stopped."
Sarah Freel, Synchro Solar

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