PEAKED-ROOF VENTILATION: CUTTING THROUGH ASPHALT SHINGLES

THERE ARE pros and cons TO pulling (removing or peeling off) asphalt shingles over a peaked roof prior to cutting operations. There are different schools of thought in many departments. Some preach pulling or scraping off the roof covering, exposing the roof decking underneath. Many opt to cut right through the asphalt shingles without first exposing the roof deck material.

When discussing peaked-roof ventilation, it is important to understand the type of roof support system with which you are dealing. Age determines the likely method of peaked-roof construction: In my area of the country, a peaked roof more than 40 years old is likely rafter construction; one between 20 and 40 years old may be rafter or lightweight truss construction; and any peaked roofs less than 20 years old are usually of truss construction. This general rule does not apply to roofs that have been altered or renovated. Although rafters are arguably stronger than trusses, both are extremely dangerous. With any peaked-roof operation, you must realize that rafter construction and truss construction are both considered Type V, wood-frame construction, and be aware of the inherent dangers associated with operating on these roofs. Making an inspection hole to identify structural members and conditions in the attic space/cockloft is a simple procedure that will assist in any type of roof ventilation. This does not require removing any roof deck covering and provides fast and accurate information.

“ADVANTAGES” REFUTED

What does exposing the roof decking really accomplish? Don’t we expect to cut it anyway? We may not elect to cut through a metal covering, but it likely wouldn’t be buried under asphalt shingles. Below are some supposed “advantages” to pulling asphalt shingles.

I can see what I am cutting-it may be tongue-and-groove boards, plywood, or oriented strand board (OSB). Even if we identify the roof deck construction, we still have to cut our ventilation hole. The exception would be slate or tile roofs or even the newer ones using plastic tiles that resemble terracotta, where it may be quicker to remove the covering prior to cutting. Our focus here is on the more widely used asphalt shingle roof covering.


This firefighter is pulling the asphalt shingle roof covering to expose the roof deck. The additional time spent on this roof will not significantly improve the efficiency of this operation and may contribute to his death. (Photo by author.)
Click here to enlarge image

In addition, it will be very difficult to attempt to pry off asphalt shingles when operating from a tower ladder bucket or an aerial ladder. This is still the safest work platform when operating over rafters and trusses-ventilating truss roofs should only be done from an aerial device. Attempting to tear off shingles takes time and adds another element to the procedure. Because of the numerous nails in the shingles, it’s difficult to get a clean line or tear. Many older dwellings have multiple layers of roof shingles, making them more difficult to remove. We have commonly seen three separate layers of asphalt shingles nailed on top of each other, making up to a 212-inch built-up layer of shingles-not something that can be rapidly removed by anyone on a burning building! Some departments even go to the extent of keeping a roof spade tool (used by roofers) in their tower ladder buckets to remove shingles.

Here is a quick and easy procedure: If a ridge vent is present, open it to examine the attic/cockloft space for the type of structural members and fire/smoke conditions.1

It saves wear and tear on your saw blades and axes. I have major issues with this. This is a serious safety issue. We cannot ever jeopardize personnel safety just to extend the life of a replaceable or repairable tool.

Axes can be replaced or resharpened with a hand file, and tar can be removed from the blade with diesel fuel and steel wool or by using a wire wheel on a bench grinder.

Saw blades or chains are easy to replace or resharpen. Don’t attempt to clean a chainsaw blade with a wire wheel on a grinder. In one case, a firefighter lost the tip of a finger when the chain was dragged into the wheel assembly. Soaking these blades in diesel helps remove tar. If not prepared to do this in-house, send dull chains and blades to a reputable saw sharpening company.

Maintaining saws, blades, chains, and tools is just the “price of doing business.” A major league baseball manager doesn’t change operations or complain about the price of baseballs or bats; it’s just part of the cost of doing business. We cannot let the cost of resharpening saw blades or chains dictate tactics that affect our safety. Even if it were an issue, a well-kept saw with a carbide- tipped blade or chain will quickly overpower the majority of lightweight peaked roofs we intend to vertically vent.

Remember how limited our time window of opportunity is in this tactic. With today’s lightweight truss construction, we have the smallest window of opportunity to date in terms of safe operations. The dangers of extending a crew’s time on a lightweight peaked roof far outweigh the benefits of removing the asphalt shingle roof covering. With recent construction practices and firefighter deaths not significantly changing, we must work smarter, not harder. We must be proactive in our approach to vertical ventilation. Keep saws, blades, chains, and other tools well maintained and ready to go at a moment’s notice. We will have all the time in the world to resharpen blades and chains after the fire.

Endnote

1. Rieger, Kai W. “Roof Ventilation: Quickie Ridge Vent Cut,” Training Notebook, Fire Engineering, March 2000, 24-25.

KAI W. RIEGER, a 16-year veteran of the fire service, is a captain with the Jackson Township Fire Department in Canton, Ohio. He is a fire instructor at Stark State College in Canton, Ohio, and at Buckeye Career Center in New Philadelphia, Ohio; a hazardous materials technician; and an assistant control officer for the Stark County Hazardous Materials and Confined Space Response Team. He has a bachelor’s degree in management and an associate’s degree in fire science.

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