OSHA defines a "steep roof" as any roof with a rise/run ratio over 4:12 (18.43 degrees). While most standard-pitched residential roofs seldom exceed a 12:12 pitch (45 degrees), the landscape is occasionally marked by a design which harkens back to earlier times, when much greater roof pitches were more common. Architecturally described as a "dramatic pitch," the extremely steep roof (ESR) is considered to have a pitch in excess of 12:12, up to a plumb vertical plane.

OSHA defines a "steep roof" as any roof with a rise/run ratio over 4:12 (18.43 degrees). While most standard-pitched residential roofs seldom exceed a 12:12 pitch (45 degrees), the landscape is occasionally marked by a design which harkens back to earlier times, when much greater roof pitches were more common. Architecturally described as a "dramatic pitch," the extremely steep roof (ESR) is considered to have a pitch in excess of 12:12, up to a plumb vertical plane.

The roofs that fall into this category are most often classified as lower gambrels, mansards, A-frames, and either Carpenter Gothic or Victorian Gothic Revival roofs.

Photo courtesy of CertainTeed.
Structurally, the ESR has a number of drawbacks and benefits. Roofs with steep slopes pose obvious difficulties for construction and repair. While the initial material/labor/equipment (MLE) construction costs for ESRs may prove quite prohibitive under most budgets, it is their replacement costs that are the most startling of all. When it comes to stripping off, cleaning, and reapplying felt, membrane and shingles, the MLE composite figure jumps up by an astounding factor for extremely steep roofs. While it is true that every degree of slope above 12:12 makes work more difficult to plan and execute, I have experienced a quantum change in difficulty arising beyond 20:12 pitch (59.04 degrees) and then again at 36:12 (71.56 degrees). A typical operation, such as simply storing or handling a bundle of shingles, becomes a strategic puzzle that should be solved entirely on the ground prior to ascending the roof. Detouring and backtracking during any ESR roofing operation not only subtracts significant production hours in the shift, but also tends to drain the roofer's physical reserves rapidly.

Once a single roofer's physical endurance becomes strained on an ESR, he should be replaced immediately. This is not only for his personal safety, but the crew strength ultimately diminishes geometrically as co-workers are overloaded with compound physical chores inherited from a strained crew member. A fully productive eight-hour shift is often impossible to achieve, especially in the initial phase of the project. Even an experienced ESR roofing crew performs at a reduced productivity level under the best of conditions. Laboring on a 24:12 pitch roof more closely resembles steeplejacking or big-wall rock climbing in Yosemite than a domestic roofing project. The fact of the matter is that ESR projects, by necessity, not only necessitate new mental tactics but the application of eccentric and extended forces to muscles and tendon groups not typically engaged on most roofs.

This article may not be the proper forum to adequately describe an occupation as difficult and high-risk as steeplejacking. As a result, I have not included any information from the steeplejack industry, nor do I profess any personal knowledge about their craft. I will, instead, present just a few of the assessment issues I have encountered in my experience on extremely steep roofs. Keep in mind that I am evaluating procedures and conditions based on my own limited personal contracting experiences with extremely steep roofs.

Estimating an ESR Job

As a construction estimator for many contractors over the years, I am relatively experienced at building a project on paper. I break the project into phases and the phases into steps before estimating the material, labor and equipment to complete any particular step in the process. Many extenuating circumstances must be allowed for, such as seasonal weather, holidays, site conditions, and crew experience, as well as the accountability, availability and affordability of the materials and equipment.

While there is no published mathematical formula for multiplying a typical square foot bid estimate by a magic "steep roof pitch factor," the estimating criteria certainly change dramatically for an ESR. I have provided a table illustrating typical ESR pitches for this article, based solely on those extremely steep roofing and waterproofing jobs I have experienced. (See Table 1.) The columns indicating the difficulty factor and efficiency rating are purely subjective and will depend on your own tracking history, types of jobs and manpower skills.

The material takeoffs are not hard to tackle, but the degree of slope may have an influence on the weight, size and the quantity of materials you want to handle at any one time. The smaller the length of valley flashing and underlayment, for instance, the faster the application rate and therefore the less stress on the roofers. The total equipment number will obviously encompass more personal fall arrest equipment, positioning and self-rescue gear, extensive personal protective equipment, hydration devices, scaffolding and catch platforms, debris and personnel netting, aerial work platforms, forklifts, ladders, hoists, and debris chutes than you ever thought necessary before. Items as small as voice-activated (hands-free) radios could be a great benefit to a crew of roofers hanging in bosun's harnesses, unable to turn around to make eye contact or even shout to their ground men.

Obviously, it is the labor that significantly drives the ESR estimate. I would encourage roofing contractors to "task track" each worker on an ESR roof project, assigning a code to each task to which the roofer assigns his labor hours in any single work shift. In this way, the contractor can construct a viable task history, enabling him to make a more accurate estimate on similar projects in the future. You can expect an ESR to cost anywhere from two to six times the labor per square of a comparable, lower-sloped roof, depending on the multiple pitches and prominent features of the roof. Keep in mind that the more you practice your ESR crews, the safer, more efficient and more profitable ESRs will become.


This assessment concept involves the "what" in the estimate. If an experienced roofer was similar to a well-traveled explorer, then working an ESR can be considered landing on another planet. There is nothing to compare it to unless you have experienced rock climbing. Determine the tasks you expect everyone to accomplish during each shift. Reduce that quantity by two-thirds for the first third of the job. Reduce the quantity by one-third for the second third of the job. The final third of the work is what remains to be accomplished in the last third of the schedule. Create a critical path method (CPM) schedule which graphically depicts not only the sequence of events but also the transitional details and landmarks that make all the difference in an ESR.

Depending on the specific roof conditions, your tasks may change size, shape and sequence as your crew progresses. For instance, you may discover that snapping reference chalk lines on the old course above and stripping a quarter square at a time and laying new shingles on an overlapped Grace underlayment patch may increase your overall efficiency rating by as much as 25 percent. The time/space difficulties generated by lateral traversing and vertical belaying for each phase of the project may be avoided by keeping the suspended roofer stationary for as long as possible.

One of the most successful ESR labor allocations I've discovered is the two-up, two-down crew method. Rather than putting a single crew on the roof, we maintain a second experienced roofing crew on the ground as laborers and support. We divide the work shift into four segments and rotate the roofing crews every two hours. The three, equally spaced breaks are 30 or 45 minutes each (depending on conditions), and they include bathroom breaks, mandatory hydration and a small, balanced energy meal. Each crew is led by its foreman in stretching exercises before resuming work. In this way, we maximized daily productivity, minimized the daily, individual physical injuries and mental stress on each individual roofer, and practically guaranteed the endurance of the crews over the extended length of the project. Believe me when I tell you that mental endurance can be the most important factor on an ESR job.

The frequent breaks accomplished several other non-quantifiable goals. They tended to improve crew-to-crew and foreman-to-crew communications, an asset to any jobsite where you seldom travel to visit when it takes so much time and energy to get up to and establish your personal work position.


This assessment component is the "where" in the estimate. When you look at the ESR roof plan, it is important to divide the roof decks into smaller, more reasonably achievable portions. Not only is it difficult for the roofer to move across the roof plane, but the assigned partner should have the shortest travel distance to hoist material deliveries from the ground crew to the ridge and belay them down to the roofer below. This face-to-face method is usually the most efficient ESR method of material delivery. It often utilizes a rigged "shingle sled" which is controlled by the ridge man and stationed within reach of the applicator. During the demolition phase, the demo chute is often moved, positioned and anchored by the ridge man, leaving the roofer with both hands free to rip up the old roofing.

As with high-angle rope rescue techniques, the supervisor (or leader) should always be familiar with the goals of each shift segment and know when to change the standard operating procedures when these goals are not being adequately achieved. One of the simplest tools we use is a scale roof model made out of cardboard and hot glue. This way, the whole crew can visualize the roof in all three dimensions and the pre-job and pre-shift procedures can be outlined graphically with the crew before work commences. Some portions of an ESR can actually be "reverse laid" from ridge to eave, as it is a process that is slower than usual roofing practices, timing itself well with the extended rope-management delays, as well as an intuitive method that works with, rather than against, the relentless gravitational pull of the earth. This process also maintains the smallest weather-exposed roof area for occupied buildings and provides an unusual psychological advantage for the roofer to visually observe his hourly progress above him, rather than his work obscured below.

Material Handling

Either during demolition or replacement, the laying of hands on roofing materials comprises most of your work shift. When it comes to ESR work, the planning for material handling will ultimately determine the success or failure of your project. Improperly locating materials on an ESR may prove disastrous as workers attempt to make the best of a difficult situation and adapt their carefully planned suspension procedures in order to reach and retrieve materials out of safe reach. Like maintaining a pitch count in a major league game, knowing the total number of moves each member of your ESR crew is expected to perform per suspended hour is critical to the success of the project, whether it was bid as a total lump sum or by the time and materials method.

Placing material too early or too late is an obvious error on an ESR. High-angle roofers waiting patiently for the next material delivery by the laborers can quickly reach exhaustion levels as the lactic acid begins to build up in their striated muscles. Delivering too much or too little in the way of materials once you're in a bosun's seat on a scorching June afternoon can be severely debilitating. Just like practice on a gymnasium rock wall, any time spent by roofers and riggers drilling cooperative moves on a practice deck set up 10 feet off the ground will pay for itself many times over. Once you start ESR work at height, the ability to adjust aerial moves becomes a significant drain on profits and an incalculable safety risk. You can set the practice deck below a tall oak and use a dependable section of the main trunk as your primary rigging anchor. Secondary anchor points may be selected by the competent person for the drills. Use small, lightweight practice loads at first and increase their mass until the efficiency of the rigging and roofing are maximized. Move your roofing and rigging team members around until the right combinations are discovered.

Workers should be encouraged to abort their work and be grounded by rappel or belay for their allotted recovery time without any argument or delay. This is the prime directive of the ESR worker. The true mark of an expert climber is knowing when he is approaching within 50 percent of his physical and mental limits before he lacks the energy or concentration to carefully secure the aerial work site and safely descend to the ground or to a refuge point.

Spending precious minutes finishing off a course of slate instead of rappelling to the ground may prove to be a disastrous decision. Therefore, except when it is infeasible or creates a greater hazard, all rappelling should be done while on belay. The precisely timed delivery of adequate new materials or belay of demolition materials in the exact position is the key to maximizing aerial time and ensuring the roofers' safety on any ESR project.

Personal Protective Equipment

The most common complaints expressed by most high-angle rope workers involve reaching their elevated work station only to find out that they are short on necessary equipment, brought the wrong type of equipment for the task, or brought more equipment than the task required. Even a good ESR plan needs revising and amending. Some of this necessary equipment will undoubtedly include personal protective equipment (PPE). Some items will be more personal than operational. The suspended roofer's physical comfort has so much to do with his efficiency, endurance and capability. Hardhats with chinstraps should always be worn, as falling objects are always a potential on ESRs. Leather-palmed riggers' gloves (sometimes with open fingers for dexterity) are also mandatory, as rope burns and contusions are common high-angle rope climbing hazards. In both demolition and installation, eye protection is essential, as falling debris and wind gusts can blow fine particles into the eyes. I know roofers who carry eyedrops on the job just to wash out offending eye contaminants without leaving the roof. Roofing shoes and boots are always a personal choice for roofers. I prefer the Cougar Paw boot for almost every roof surface. However, work on ESRs can often be expedited by using traditional rock climbing shoes with extremely flexible fabrics and sticky rubber soles and toes.

Let's not forget the effect of environmental elements on rope suspension. Hard physical work creates sweat. In the summer, we want that to evaporate and cool, while in cold months we want to wick it away from the skin and let it transpire out through a Gore-Tex® shell without affecting perimeter insulation values. These conditions often require different materials and ensembles.

Hydration "early and often" while on the roof can be just as important in cold weather as in warm weather. Dehydration is proven to accelerate the onset and depth of suspension trauma symptoms in the suspended vertical rope worker. There are even Class III full-body harnesses manufactured with camel water bags and sipping straws attached to the shoulder strap. PPE is selected by the competent person by means of performing a written job safety analysis (JSA). Equipment selection is primarily based on site-specific, task-specific, worker-specific acts and conditions. Make sure you've selected, trained and inspected your PPE specifically for ESRs.

Rigging Plan

How any roof will be rigged for personal fall arrest, work positioning, vertical access (belay/rappel), horizontal access (traverse) and rescue is absolutely essential to getting the work done. In this regard, the scale model will pay for itself many dozens of times over. A complex fall prevention and protection plan should involve not only personal fall arrest systems (PFAS) and ropes, but also ladders, supported and suspended scaffolding, aerial work platforms and materials handling devices. When you actually tie nylon strings on your model representing horizontal and vertical lifelines and deploy workers represented by small steel nuts tied on these lines, you can physically manipulate the model to practice the exact maneuvers you intend your crews to perform. A few hundred dollars spent at this level can potentially generate thousands of dollars in profit at the job's completion.

As with any personal fall arrest system, it is the PFAS installers who are the most problematic. What is the most feasible means to protect them during their at-height rigging procedures? Are these practices actually creating a greater hazard or providing safe access and adequate fall protection to those building the means of access and fall protection? Experience and training are crucial to the successful PFAS rigging team. The competent person and team leaders should work very closely with the expert climbers.

In an effort to follow the KISS rule ("Keep it simple, stupid") I recommend the use of horizontal aircraft lifelines anchored along ridges and hips. These should be covered with different colored vinyl coatings representing their application.

Vertical lifelines attached to each horizontal between anchor points will enable any roofer traversing the deck to connect to the next line by means of a 100 percent tie-off, double-leg lanyard. This method leaves one leg of the lanyard attached to the lifeline you are abandoning until the second leg is attached (via rope grabs) to the next lifeline you are accessing laterally, prior to releasing the rope grab behind you. We often attach small canvas bags filled with lead shot to the tails of the lifelines to stabilize them and allow roofers to more easily raise a rope grab under tension.

Vertical Access

A vertical ascent may be made by either hoisting the roofer with a mechanical advantage (MA) block-and-tackle on belay or else by a series of self-applied "jumps" using ascending rope-grab devices. By wearing a bosun's seat harness, the left-handed ascender is connected to the two D-rings of the seat strap and a separate right-handed ascender is attached to a single or double foot loop. Bending you knees and raising the right-hand ascender and then standing allows you to next raise the left-hand ascender until the bosun's seat is tensioned across the buttocks. Then sit in the seat and repeat the motions. In this way you may "inchworm" your way up the vertical lifeline in 1-foot or 2-foot increments. While it can be quite a laborious process, it gives you 100 percent control over your motion, unlike the hoist and belay.

Hoisting may be performed by a partner in a secure position on the ground or else by the roofer himself. The problem with the latter is a matter of rope management. While both hands are occupied in the pull, it can become quite congested right in front of you where your feet and knees are often impinging or entangling rope. Hoisting pulleys incorporate a fall protection device, which allows you to hoist but locks on the rope when pull tension is released. If the need to lower occurs, the rope lock cam may be released manually by pulling on another accessory cord, retracting the spring-loaded cam. This procedure must be performed cautiously. I strongly suggest conducting extensive drills on a simulation practice board close to the ground before any of these ESR operations are ever attempted at a hazardous height.

Vertical descent is often a practice of self-belaying or rappelling from a fixed anchor down the roof slope. There are a number of rock climbing devices designed to attach 10 mm (22 kN) dynamic kernmantle climbing ropes for vertical descent. Most of them employ a friction braking design, which, in the hands of an inexperienced climber, may produce heat and potentially damage your ropes. In other words, practice is never over. When in doubt, check it out. Are all of your tools properly holstered and tethered out of the way? Are all primary anchors backed up with secondary points? Are live lines tested and dead lines deployed out of the way? Are all of your ropes, knots and devices considered "bombproof" before loading?

Lateral Traverse

Traversing an ESR deck while suspended may not be as physically demanding as ascending vertically, but it can prove to be an arduous task nonetheless. If you haven't secured lateral lifelines and redundant anchorages, conducted a rope management review of the operation or practiced lateral maneuvers on your practice deck, you may find yourself unprepared for the task and often at the worst possible time.

The traverse can be mentally challenging, and planning is essential. You want the ability to go anywhere on an ESR without difficulty or delay. Some amount of ascending or descending may also be achieved simultaneously if the move is well designed and practiced. As with ascending, you want to plan rest stops occasionally to shake out the lactic acid buildup in your muscles, re-oxygenate your blood and clear your thoughts. Pain can cause you to hurry to a destination unnecessarily. Running a "pitch" to the end often becomes an obsessive goal rather than a cautious, calculated procedure. Whenever you are suspended in a high-angle rope system, you must always consider the hazard analysis of every planned move. What is the probability of something going wrong and how serious are the consequences if it does? This leads us to the last part of the ESR assessment.

Emergency Action Plan

ANSI/ASSE A10.32 (2004), "American National Standard for Fall Protection Systems for Construction and Demolition Operations," states in Section 6.2.2, "A project-specific rescue plan shall be developed which will provide for a form of rescue for employees." This roof-specific rescue plan should include training employees in self and assisted rescue as applicable to the rescue scene. Every location where a roofer could eventually come to suspended arrest should be identified and classified. For each class of rescue, a plan should be developed and drilled for improvements by the employer. Section 6.2.3 also states, "All rescuers shall be provided adequate training, equipment and personal protective equipment where needed."

It is virtually impossible to determine how much training, equipment and PPE is adequate without drilling your plans. Likewise, without hands-on evaluations of simulated ESR maneuvers no one can say precisely where and when rescue operations will potentially be needed.

Rescuing an ESR roofer who's been subjected to an arrested fall has few of the complications associated with typical low-pitch eave rescues. The roof edge transition between a 6:12 pitch and a vertical suspension can present a daunting obstacle to both self- and assisted-rescue techniques. On the other hand, victim access after a post-arrested-fall (PAF) can be very challenging on an extremely steep roof. While it may not be feasible or practical to keep roofers on belay at all times, the employer's on-site, designated competent person for fall protection should be very cautious as to when and where work may be allowed off-belay. If a suspended roofer calls for "on-belay" before a rappel, this may represent a reasonable and well-practiced exercise for the roofer and his ground support crew. However, an injured and/or unconscious worker suspended over 100 feet above street level can pose a complicated rescue plan.

The point is that every employer has a duty to implement a site-specific rescue plan for every roofer in every position that workers may potentially be suspended after a fall. According to OSHA, this rescue, along with any emergency medical treatment required, must be "prompt" and "available." Most importantly, this rescue plan should be certified by the employer, with methods established for pre-qualifying rescue personnel, approving specific rescue methods, and inspecting rescue equipment. Rescue teams should be regularly drilled, self-critiqued, and evaluated before re-drilling to confirm corrections. The safety officer should not hesitate to take damaged, degraded or suspect rope or equipment out-of-service and destroy it.

Every roof requires a new rescue plan, and every plan should be designed for the worst-case scenario. In plain English, if you've never hand a hands-on drill of a written rescue plan, then you have no plan. Train like you rescue. Rescue like you train. Remember, the elements of the rescue scene evolve as real-life problems occur. In the beginning, we might simulate a rescue victim using a 50-pound bag of feed in a full body harness suspended on our practice roof on the ground. As we improve, we might replace the bag with an 80-pound canvas manikin and practice on a single-story roof. Once we are confident with our plan and practice, the rescue of a 180-pound, fully articulated "Rescue Randy" manikin on an ESR at full height.

You should also instruct your ESR and rescue teams on the symptoms, effects and prevention practices of suspension trauma (ST). It is a constant and serious threat to all those whose occupations require they be suspended. Recognition and prevention are essential to aerial survival. Most importantly, the employer must train his in-house rescue personnel in the Rescue Prime Directive: The safety of the rescuer comes before the completion of the operation.

In other words, no high-angle rope rescue ever got easier by adding a second victim. If all of this attention to high-angle rope rescue seems excessive, unreasonable and just too expensive to consider in your initial bid, think about asking a victim hanging helpless at great height if he would have rather designed and practiced a reasonable rescue plan first.