Flat Roof Repair Services
Our company offers routine maintenance, upkeep, and overhaul of existing flat roof systems. However, we often find there are specific issues, repairs, or fixes needed. We provide repair to acute and specific issues as well.
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In addition to simply making repairs, we can provide a full expanse diagnostics report of conditions of a flat roof. The detailed breakdown helps building owners plan and prioritize repairs.
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Some of the types of repairs that fall into this category follow:
Termination Repair
Most roof terminations, and typical Washington D.C. Capitol Hill flat roof systems, are built with a subclass or a type of flashing. Most flat roof systems cannot simply end at the edge of the horizontal roof without a proper termination. The termination is basically a separate type of element that has been added to the edge of the roof to securely fasten the otherwise open edge of the roof membrane to the side or edge of the roof. In some cases, the roof will terminate at a rear fascia board. This particular configuration is extremely common in residential applications, for example. The roof membrane, in those cases though, must terminate with a field formed or pre-bent metal termination, in almost all scenarios Yet, the average (and below average) roofers do not always do this correctly.
In other cases, at the sides of a building, the roof will generally terminate at a coping metal on top of a parapet wall. Generally, the roof membrane is required to be terminated with the side edge secured under a metal or alternative type of material coping. The coping not only secures the single-ply or low-slope type roof membrane but also seals the outer edge of the roof membrane from weather and rainwater.
At the open edge or side of a flat roof system, similar to the rear of the building, the roof will generally be terminated with a gravel stop, drip edge, or alternative type of metal which wraps over the wooden fascia board that runs down the side of the building. Alternatively, a ridge cap will generally be installed at the transition to terminate a low-slope roof from a higher-pitched mansard roof, where the mansard roof covers the exposed portion of the roof system at the front facade area of the building.
A few years back, our company wrote an article in the Capitol Community News and MidCity News, about this topic and issue. (You can click here to see one of the original postings of that article.) The issue of ponding at rear drip edges is such a big issue that maybe as many as 1 out of 10 Capitol Hill, DC roofs will end up leaking because of poor installation that derives from defective rear termination at flat roofs. If that single issue could be solved, so many other related, consequential problems could be avoided.
Flashing Repair
Roof flashing is a common and prolific component in flat roof systems that serves as a waterproof barrier at intersections, penetrations, and transitions between different roof surfaces or building elements. Flashings are commonly found at terminations at the perimeter of the roof and or any appurtenances or penetrations of elements that go through the roof system. You could think of them basically as a bridge that joins between the roof membrane itself and all of the many accessory elements at the perimeter and interior of the roof system. Flashings are designed to prevent water infiltration which, like the roof system itself, protects the underlying roofing materials and building structure from potential damage caused by moisture. Flashing is typically made of moisture resistant and waterproof materials, such as metal (like galvanized steel or aluminum), rubber, or specialized synthetic membranes, and is integrated into the roof system to create a continuous, watertight seal. Over the past decade and more that we've been working in Capitol Hill and on the light roof buildings of Washington DC, we are often tasked with the job of repairing and or replacing roof flashing where they are deteriorated, defunct and / or improperly installed.
Flashing repairs are often required for the following reasons:
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Age and weathering: Over time, the flashing materials, such as metal or thermoset flashings, can deteriorate due to exposure to the elements, including UV radiation, temperature fluctuations, and extreme weather conditions. This can lead to cracks, splits, or holes in the flashing, compromising its ability to prevent water penetration.
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Movement and settlement: Flat roofs are susceptible to natural movement and settlement caused by structural shifts, thermal expansion and contraction, or ground movement. These movements can cause the flashing to separate or detach from the roof surface or adjoining walls, creating gaps and openings for water to seep through.
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Improper installation: If the flashing was installed incorrectly or with substandard materials, it may not provide adequate protection from the very beginning. Flashing requires specific installation techniques and adherence to the building code to sealing and work properly.
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Damage from HVAC and MEP and Trees: Flat roofs are often damaged in the “normal” course of work by OTHER contractors for a variety of reasons. As well, depending on trees above, the roof may be susceptible to falling debris from nearby trees or structures. This can lead to punctures, tears, or dents in the flashings, compromising their effectiveness.
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Roof penetrations and protrusions: Flat roofs often have various penetrations or protrusions, such as vents, skylights, or HVAC equipment. The flashing around these areas is particularly vulnerable to leaks and damage, as it must be carefully integrated with the roof membrane and the penetrating objects.
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Expansion joint failures: Flat roofs may have expansion joints to accommodate thermal expansion and contraction. If these joints or the flashing around them fail, water can seep into the roof system, potentially causing significant damage.
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Pests and Rodents: We really don't believe this issue is limited to Washington DC, but here in neighborhoods like Capitol hill, again and again, we see areas where animals like raccoons, squirrels, and birds have bent or removed pieces of flashing to gain access into attic spaces or warmer interior spaces in the winter.
GL Barnhart Construction can proactively address these flashing problems and issues which are part of the upkeep and repairs needed to keep a roof functioning properly. Regular check ups and timely repairs can help prevent water infiltration, extend the lifespan of the roof, and avoid more costly repairs or replacements in the future.
Roof Coating and Recoating
Low-slope and flat roofs here in Washington, D.C., and Capitol Hill generally fall into two very specific categories: 1. Roofs that need coating and re-coating, and 2. A different set or grouping of roofs which do not require coatings at all. There's really no gray area or middle ground; it's either the one category or the other. Many of the newer generation of single-ply thermoplastic roof materials never need to be coated. They are designed and manufactured with a high-reflectivity top layer which resists the majority of the deleterious effects of ultraviolet radiation exposure from sunlight.
Material Science
The material science related to the development of UV-resistant roofing materials involves polymer chemistry formulation and radiation blocking mechanisms to reduce photodegradation. Ultraviolet radiation from sunlight is a potent energy source that can break down molecular bonds in polymeric materials, leading to a process called photo-oxidation. This degradation process causes certain roofing materials to become brittle, discolored, and ultimately lose their structural integrity and performance properties related to resilience. Immediately this may make sense to most people because we're taught to protect our skin from the harmful effects of sun exposure, think about a sunblock commercial. Unlike a roof surface though, people can put on a shirt or sit under an umbrella at the beach. Flat roofs though, on the other hand cannot move their position, they are fixed, locked in place, stuck in the sun every single day, all day long. For some roof material classifications, this coating is their only protection.
Technological Advancement
Over the past five decades, technology has evolved just enough to combat some accelerated UV related degradation with fluid applied chemical coatings. UV-stabilizers and absorbers are incorporated into the polymer matrices of advanced coating material classes. These additives work by absorbing or dissipating the harmful UV radiation, preventing it from initiating the photo-oxidation process. The use of highly reflective surface coatings or topcoats can help reflect a significant portion of the UV radiation away from the underlying material, further reducing its exposure.
The engineering behind these UV-resistant roofing materials also focuses on optimizing their physical properties, such as tensile strength, elongation, and tear resistance, to withstand the harsh environmental conditions prevalent in regions like Washington, D.C. This involves specific allocation and blending of polymers, reinforcing fibers, and other additives to achieve the desired balance of properties.
Roof Life Extendability
Accelerated weathering tests and long-term exposure studies are conducted to evaluate the performance of most high-performance materials under simulated and real-world conditions. These tests help manufacturers refine their formulations and manufacturing processes, allowing the roofing materials to withstand the rigors of ultraviolet radiation exposure for an extended period of time. While high quality coatings minimize the need for frequent replacement or costly maintenance, roofs must be recoated within a 3-7 year time frame.
Cost Savings
By understanding the material science, optimal coating applications can offer high-performance, low-maintenance solutions that provide reliable protection against the damaging effects of ultraviolet radiation, ultimately leading to longer-lasting and better cost-effective flat roof systems.
As a company focuses on extending the lifespan of flat roofs, it's shocking to see how many building owners are unaware of the condition of their roof coatings. By simply using a roof contractor like GL Barnhart Construction, they can save thousands.
Delamination and Fishmouthing Repair
Although single-ply and other types of flat roof systems often appear to be a single continuous membrane throughout the surface of the flat roof, the roof membranes are actually individual layers of membranes applied in sections. Starting at the lower end of the roof, layers will be applied in succession, working from the low areas up to the high areas, with the upper areas overlapping the lower areas of the roof. These layers are applied with an intended overlap so that the upper section of the roof membrane overlaps the lower layer, and the upper layer is sealed on top of the lower layer.
However, sometimes the membranes can experience issues or problems with adhesion, resulting in delamination. Delamination refers to the separation or peeling apart of the individual layers of the roof membrane, causing them to detach from one another. This separation can occur between the overlapping sections of the membrane or within the membrane itself, where the various plies or reinforcing layers begin to separate.
Delamination can be caused and compounded by external factors such as weather conditions, particularly moisture and temperature fluctuations. Water infiltration, either from leaks or condensation, can weaken the adhesive bonds between the membrane layers, allowing them to separate. Additionally, extreme temperature changes can cause the materials to expand and contract at different rates, putting stress on the bonds and promoting delamination.
When delamination occurs, it can lead to a condition known as "fish mouthing." Fish mouthing is a term used to describe the separation of the membrane layers at the overlapping seams, creating a gap or opening that resembles the shape of a fish's mouth. This opening can allow water to penetrate the roof system, potentially causing leaks and further damage to the underlying components.
External factors like wind uplift, foot traffic, or debris impact can also contribute to fish mouthing by physically separating the membrane layers at the seams or causing tears or punctures in the overlapping areas.
To repair delamination and fish mouthing, a set of steps must be followed, although each type of material and system requires specific materials and procedures and methodologies. This includes ensuring that the surface is clean and dry before applying the membrane layers, using the correct adhesives or welding methods, and ensuring that the overlaps are properly sealed and secured. Regular checkups and maintenance can also help identify and address any early signs of delamination or fish mouthing before they become more severe issues.
By understanding the underlying causes and mechanisms of delamination and fish mouthing, we can take proactive measures to mitigate these problems and extend the lifespan of flat roof systems, ultimately providing better protection and performance for the building.
Corroded Metal Prevention and Repair
Metal flat roof components, such as terminations, gravel stops, drip edges, flashing, and adjacent equipment like HVAC units, are integral parts of flat roof systems. These components are often exposed to harsh environmental conditions, including moisture, temperature fluctuations, and atmospheric pollutants, which can accelerate the corrosion process.
Corrosion is a natural phenomenon that occurs when metals react with their surrounding environment, leading to the gradual deterioration and degradation of the material. On flat roofs, corrosion can manifest in various forms, such as rusting, pitting, scaling, or the formation of corrosion products like oxides or salts.
The consequences of metal corrosion on flat roof components can be severe. Corroded terminations, gravel stops, and drip edges may lose their structural integrity, leading to detachment or separation from the roof membrane. This can create openings for water infiltration, potentially causing leaks and water damage to the underlying roofing materials and the building's interior.
Corroded flashing around penetrations, such as vents, skylights, or HVAC equipment, can also compromise the watertight seal, allowing moisture to seep into the roof system and potentially causing further damage.
Moreover, corrosion on adjacent equipment like HVAC units or other mechanical components can lead to equipment failure, compromising the building's functionality and potentially posing safety risks.
As a flat roof repair company, we take a proactive approach to monitor, maintain, and repair issues related to metal corrosion. We can conduct routine, seasonal inspections of flat roof systems, paying close attention to metal components and identifying any signs of corrosion in its early stages. This is a part of our typical process during checkup and condition surveys.
We use a variety of techniques to mitigate and address corrosion problems. These may include:
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Cleaning and surface preparation: Removing corrosion products, debris, and contaminants from the affected areas to prepare the surface for repair or protective coatings.
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Repair and replacement: In cases of advanced corrosion, we may recommend the repair or replacement of the affected components to restore their integrity and functionality.
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Protective coatings: Applying specialized coatings or paints that act as barriers against environmental factors, inhibiting further corrosion and extending the lifespan of metal components.
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Cathodic protection: In severe cases, we may employ cathodic protection systems, which requires separation between dissimilar metals with Impermeable and / or resilient materials to prevent or control corrosion on metal surfaces.
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Material selection: For new installations or replacements, we recommend corrosion-resistant materials, such as aluminum or stainless steel, which are better equipped to withstand harsh environmental conditions.
By taking a proactive approach and employing these techniques, our company helps building owners and property managers maintain the integrity of their flat roof systems, mitigate the risks associated with metal corrosion, and extend the lifespan of their roofing investments.
Penetration Repair
In previous sections, we discussed the importance of flashing maintenance and keeping up with repairs. Penetrations through the roof system, such as those for mechanical, electrical, plumbing, and HVAC equipment, are often flashed with impermeable materials or resilient sealants. However, resilient sealants alone should not be the primary means of defense for these penetrations.
There are a multitude of different types of penetrations through roof systems, accommodating various equipment, pipes, and lines. While contractors from trades like mechanical, electrical, and plumbing may be skilled in their respective fields, they are often not trained in proper roofing means and methodologies. Roofing and water management is a trade and science within itself, requiring specialized knowledge and techniques.
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Although these non-roof trade professionals are experts in their areas, they frequently lack the expertise to properly seal their equipment, piping, or lines as they penetrate the roof membrane. This can lead to improper installations and areas of advanced or accelerated deterioration around the penetrations.
These penetration points essentially become the weakest links in the roof system, susceptible to leakage and potential problems. Even a small gap or improperly sealed area can allow water infiltration, leading to more extensive damage if left unaddressed.
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GL Barnhart Construction understands roofing and waterproofing systems and can properly seal and maintain penetrations in flat roof systems. Our team can check your roof and even perform a thorough conditions survey, examining roof penetration issues and identify potential issues or signs of deterioration.
Special sealants (high-performance, roofing specific) and materials can be applied at penetrations to properly seal and integrate them with the roof membrane. This may involve removing and replacing old or failing sealants, installing durable flashing materials, or implementing more robust waterproofing details tailored to the specific penetration type and location.
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By taking a proactive approach to penetration repair, our company helps building owners and property managers mitigate the risks associated with these vulnerable areas. Regular maintenance and timely repairs can prevent costly leaks, extend the lifespan of the roof system, and protect the overall integrity of the building.