How to Properly Use a Roof Safety Harness

Getting up to the roof safely is the first step

If you don’t own one already, buy ($200) or rent (about $30 per day) a sturdy extension ladder that extends at least 3 ft. above the roof edge. Aluminum is the lightest, but fiberglass ladders provide better protection against electrocution in case the ladder accidentally touches a power line or live wire. If possible, set the ladder on firm, level ground. On uneven ground, place squares of plywood under one foot to level the ladder base and then secure it with wire or rope tied to stakes. Fasten the top of the ladder with rope or wire tied to a secure anchoring point such as a 20d nail driven into a rafter. That will keep it from sliding sideways as you step onto the roof.

Stepping from the ladder to the roof or from the roof to the ladder is precarious and can be unnerving. Here are a few pointers to make it easier and safer:

• If possible, avoid carrying anything up the ladder. Use a helper and a bucket tied to a rope to hoist up tools and supplies.
• Extend the top of the ladder at least 3 ft. above the roof edge so you’ll have something to hang on to as you step onto an off the roof. Never step on any of the ladder rungs above the roof.
• Keep two hands on the top rung of the ladder as you step onto and off the roof.

Installing, using and removing roof brackets

Build a ‘slide guard’ with roof brackets and 2x6s as a first line of defense
Once you’re safely up to the roof, you’ll want to set up roof brackets and planks all along the eave. These serve a dual purpose. They allow you a safe place to step onto and rest tools and materials. And they also act as a slide guard that will help prevent you from falling off the edge of the roof if you lose your footing higher up and slide down.

Photos 1 and 2 show how to fasten the brackets to the roof and secure the planks. Each roof bracket should have a label on it with complete instructions. Read and follow them carefully.

First locate a truss or rafter—the roof brackets must be nailed through the sheathing and into these structural members. The exposed rafter tails on our roof made this easy. If you’re not so lucky, listen and feel for a solid spot as you tap across the roof with a hammer. When you locate solid wood, carefully slide the blade of a pry bar under the shingle to separate it from the shingle underneath, and gently bend the tab up. Then you can place the nails where they’ll be covered by the shingle (Photo 1). If you feel the nail miss the rafter (it will penetrate easily), pull it out and put a dab of caulk or plastic roofing cement on the hole to seal it. Then move the nail over an inch and try again.

Rafters in older homes are usually 16 in. apart, while trusses in newer homes are usually 24 in. apart. Both have 1-1/2 in. of nailing surface. Measure from the first bracket to find more rafters or trusses. Complete the slide guard by adding the 2x6 plank (Photo 2). Now you can safely work your way up the roof by adding more brackets and planks about every 8 ft. When you’re done on the roof, remove the brackets and planks in the opposite order, starting at the top and working down (Photo 6).

Fitting and fastening the roof safety harness

On low-pitched roofs where footing is no problem and the eaves are less than 12 ft. or so from the ground, you may feel safe working with just roof brackets and planks in place. This is OK. But for the ultimate in roof safety, especially on steeper roofs or big jobs, invest in a safety harness and rope.  Photos 4 and 5 show how to set up the harness and rope (technically called a “personal fall arrest system”). The roof anchor must be fastened securely to solid wood like a rafter, truss or ridge beam, not just through the roof boards or plywood. Models vary slightly, so read the manufacturer’s instructions and follow them carefully. Here are a few of the key points:

• Inspect the harness and lanyard for loose stitching and worn webbing. Never reuse a harness or lanyard that has been subjected to a fall. Send them back to the manufacturer for inspection. Examine the rope for fraying.
• Adjust the harness buckles for a snug fit.
• Locate the roof anchor directly above where you’ll be working on the roof. Don’t work more than 4 ft. to the side of the roof anchor. Relocate the anchor or add more anchors if necessary.
• Mount the roof anchor to the peak no closer than 6 ft. from the edge of the roof.
• Reposition the rope-grab as you work to minimize the amount of slack in the rope between you and the roof anchor.