Larger imageMechanical Units with Blocking and Clips on a Wood Roof

Source: Noson, Perbix, SSD

Purpose

To secure rooftop mechanical units.

Caution

When anchoring to post-tensioned slab, locate and avoid reinforcing.

Recommendation

Install clips and blocking.

Supplies Required

• Clips, Z and L—1/8" thick
• Lag bolts—3/8" diameter (for wood)
• Sheet metal screws—No. 10 x 3/4" (for steel)
• 4x blocking (for wood)
• Blocking—L2 x 2 x 3/8" (for steel)
• Drive pins
• Framing clips (for wood) Simpson A35

Installation

To install blocking and clips for a wood roof, follow these steps:

1. Insert 4x blocking between existing joists with framing clips.
2. Attach Z or L clip to mechanical unit with corresponding fasteners and attach to blocking. Place clips at 24" on center minimum.
3. Patch roof as required.

Larger imageMechanical Units with Blocking and Clips on a Steel Roof

Source: Noson, Perbix, SSD

To install blocking and clips for a steel roof, follow these steps:

1. Insert blocking between existing joists and weld in place.
2. Attach Z or L clip as mechanical unit with corresponding fasteners and attach to blocking. Position clips at 24" on center minimum.
3. Patch roof as required.