In previous blog topics, I identified what a sheathing or roof deck is, and different materials that may be used. The last topic on sheathing and roof decks components related to Panel Edge Clips; these are also commonly called H-clips and Panel Sheathing Clips depending on how each specific manufacturer markets them. Panel Edge Clips are installed on panel edges (either OSB or plywood) at the half-way point between the rafters. This clips adjacent panels together and allows for load distribution between panels. This provides a lot of stiffness at what would otherwise be an unsupported edge. In a previous blog on sheathing or roof deck, I identified that both plywood and OSB panels need to be installed with a gap; the Panel Edge Clips provide a uniform gap. From a roofing contractor perspective, I really like Panel Edge Clips because the stiffness allows the sheathing or roof deck to remain flat, especially at the panel transitions. As asphalt roof shingles telegraph imperfections in the sheathing or roof deck, eliminating imperfections is critical. Unfortunately, if your house was not built using Panel Edge Clips they cannot be retrofitted even with a full tear-off of all roofing materials; they can only be installed as the sheathing or roof deck is installed. If I am replacing sheathing or roof deck over a large part of your roof (perhaps as you recover from storm damage), At Williams Roofing & Construction, I always recommend Panel Edge Clips as I find that one or two boxes are all that is needed and the benefits clearly outweigh the minor cost increase in terms of both performance and appearance of the finished product. If I am replacing only a handful of damaged panels, the retrofit opportunity to use Panel Edge Clips really doesn’t present itself.
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In previous blog topics, I identified what a sheathing or roof deck is, and identified that it is commonly plywood or oriented strand board (OSB). I have further expanded this discussion to identify how plywood is manufactured, how OSB is manufactured, and why both are superior to wood planks that may have been used in distance past. However one of the questions I regularly field is OSB vs. plywood, which is superior? From a roofing contractor perspective, for new house construction the sheathing or roof deck is installed by the carpenters. For replacement roofs, for jobs the roofing contractor tears off the old roof, we have an opportunity to inspect the sheathing or roof deck and replace is necessary. Where we see damages to sheathing or roof deck, it is usually the result of a roof leak. Some factors that enter into the homeowners or roofing contractor’s decision to use OSB vs. plywood for repairing damaged sheathing or roof deck include typically limited to cost. As both are wood commodities the price of plywood and OSB are variable and change almost daily. Sometimes plywood is cheaper, sometimes OSB is cheaper. When the contractor built your house, you can bet this was the deciding factor. While some roofing companies will sell you on performance differences, the Engineered Wood Association identifies that plywood and OSB are structurally equivalent. Among the general public, there is a perception that plywood is higher quality; probably based entirely on appearance as plywood is still recognizable as wood and has an appearance they are familiar with. For this reason alone, the homeowners decision would drive plywood vs. OSB decision. I will tell you that there are distinct differences in performance with prolonged exposure to water. With prolonged exposure to water plywood is definitely the superior product. When plywood gets wet, it swells consistently and will return to its original dimensions as it dries; not so with OSB. When OSB gets wet, it can remain swollen as it dries out, resulting in sheathing or roof deck that is no longer smooth and this will telegraph through to the finished roof when using asphalt shingles (we previously identified that smooth sheathing or roof deck is critical). As a roofing contractor that has been in business over 25 years, I didn’t stay in business this long because my roofs leak. Since my roofs don’t leak, the decision to install plywood vs. OSB is job specific and includes input from the homeowner on what they prefer and the finished cost. In a previous blog topic, I identified what a sheathing or roof deck is, and identified that it is commonly plywood or oriented strand board (OSB). I am going to delve a bit deeper; what is OSB and why is it superior to wood planks? Also what makes OSB different than plywood? OSB is relatively new to the building market, coming only into common construction uses, including sheathing or roof deck, since approximately 2000. While plywood is made up of several plies that are veneered and glued together with wood grain oriented in specific directions, OSB is specifically engineered and made up of wood strands hot compressed with adhesive. While those strands may look random, the directions of the strands are strictly controlled in the manufacturing process. Plywood may have 5-7 layers; OSB may have 50 layers. In the plywood blog I identified that the plies in different directions increase the strength of plywood vs. wood planks, with OSB this benefit is magnified somewhat as the engineering and manufacturing controls can result in product where the strands are oriented in many more directions. For structural grade plywood, we already identified that there could be knots and defects, and this could result in voids internal to plywood sheet where you cannot inspect the product. OSB is compressed and will have no voids; further demonstrated by OSB weight (a sheet of OSB will weigh more than the same size sheet of plywood). Since OSB is a more highly processed and engineered product, it will be more consistent than plywood. As with structural grade plywood, since OSB used as sheathing and roof deck will be covered, appearance doesn’t matter. Which is a good thing, OSB does not have an attractive finished surface. It was engineered as a structural product though, and for that purpose it works admirably. As a specifically engineered product serving a specific purpose, it is definitely superior to wood planks. In Lees Summit, this has been a most unusual winter. We have warm days approaching 70-F, and yet only a couple of days later we have high only approaching 30-F. And the see-saw continues. These wide variances in weather conditions make me wonder what the severity of our spring storms might look like. Hail, wind driven rain, tornadoes; all widespread will damage a lot of roofs and create needs for both repair and replacement. My roofing company, as with most established roofing contractors, maintains crews based on work we have available. Following storm or natural disasters, there is far more roof work than local roofing contractors can support. This leads to an influx of migrant roofing contractors, swooping in to grab storm-related insurance work, and they will certainly move on once a larger storm happens elsewhere or once the roof replacement work dries up. I encourage you to hire a local roofing contractor for roof repairs. Your house is likely your single largest investment. And the roof is your first line of defense in protecting your house. With some types of shingles, a roof may last 25-30 years, or even longer. The reasons to select a local roofer are many: 1) The roof being installed comes with a manufacturer’s warranty. That warranty is only as good as the manufacturer that stands behind it, but proper installation is also crucial to ensure the manufacturer honors the warranty. When you select a local roofing contractor, you can ensure that the installer is available later. How are you going to get support from a migrant roofing contractor? 2) It isn’t just the roof shingles; these are only one part of a bigger system including underlayment, ice and water shield, flashing, and venting. While you only see the shingles, every component is critical. Migrant roofing contractors are chasing money only, and are likely to cut costs in ways you cannot see. Local roofing contractors that rely on referrals don’t have that luxury. 3) We are properly licensed by the state of Missouri, and even the localities we do work in. 4) We are insured, for your protection. 5) We have a proven reputation within the community; this is among our most valuable intangible assets. While I agree that there will be more work following storms than local roofing contractors can handle, and it may take some time to get a new roof, we can install a short-term solution such as a properly secured tarp roof. This may not be the most attractive, but it is likely at least some of your neighbors have these as well. A properly installed and secured tarp will provide 90-120 days of protection, which gives local roofing contractor time to schedule a proper roof replacement. Your house is your largest asset. Are you willing to trust a transient roof contractor to provide the first line of defense and protection? |
Bobby WilliamsWe are an experienced Lees Summit roofing company with over 15 years experience in repair, service and installation. Archives
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