3 More Important Layers Of Your Roof

Allstate Exteriors • June 6, 2022

If homes came with parts manuals, those instructions would take thousands of pages. For example, your central Ohio home’s roof is not a single piece but a group of parts connected together to function as a water-resistant shield over your home. Three necessary layers of the shield are the roof deck, ice and water shield, and underlayment.

Roof Deck

Your home’s attic has a “floor” of joists and a “ceiling” of rafters. These wooden support members connect the walls of your house (joists) and hold up your roof (rafters). Your roof deck comprises the rafters and sheathing. They are the foundation layer for your finished roof. The rafters are spaced closely enough to bear tremendous weight, which they transfer to your walls. The rafters are cut at angles to allow your roof to have a pitch, or steepness, perfect for shedding the worst of Ohio’s snow, rain, and ice storms. 

Atop the rafters are sheets of plywood or oriented strand board (OSB) that stabilize the rafters and allow just about any roofing material to be installed on them. These sheets of thin veneered wood (plywood) or glue and chips (OSB) are purposely nailed into place with small gaps to allow for thermal expansion. Otherwise, your roof would buckle. For your roof to last a long time and stay healthy, your roof deck must be strong. It is always part of an annual roof inspection. If necessary, defective rafters can be sistered (a second rafter attached beside the original) or replaced without disturbing the roof.  

Sheathing is usually replaced in a complete roof replacement. Your roofer’s Scope of Work and estimate may include a certain number of sheets as part of the final cost, with additional sheets specified at a given market price. Reasons to replace sheathing include:

  • Mold
  • Physical damage
  • Rot
  • Insect or pest invasion

Your roofer is best qualified to assess the condition of your roof deck. 

Ice and Water Shield

Ohio’s winters are not to be trifled with, so every roofer installs ice and water shield along the bottom edge of a roof, either at original installation or during full roof replacement. This thick, self-adhesive, spongy material seals around nail and staple holes, does not allow water to penetrate, and helps combat water infiltration from ice dams. Ice and water shield is also laid down along valleys and (sometimes) over hips. Valleys and hips are two places the different planes of roof sections meet. Anywhere leaks might find a way into your home, ice and water shield can be installed to prevent them.

Your roofer can tell, just by peering at the bottom edge of your finished roof, if you have this vital layer on your home’s roof. When looking at full roof replacement , ice and water shield should be replaced. Its self-adhesive back is very sticky, and its spongy, self-sealing qualities do not degrade with age. Unless sheathing is replaced, expect the ice and water shield to remain.

Underlayment

Your roof deck is covered in rolled material called underlayment. This thin, stapled material helps seal around nail and staple holes and is either synthetic or organic felt. Underlayment is waterproof; shingles are designed to be water-resistant. Sheathing and joists are neither waterproof nor water-resistant. Underlayment is yet another barrier against water damage to your Ohio home.

When having your entire roof expertly replaced by highly skilled roofers, expect the old underlayment to be removed and replaced with fresh underlayment. 

In Unison

Your Ohio home’s roof deck, ice and water shield, and underlayment form the bottom of your entire roofing system. They work together to give your roof the firm footing it needs, plus offer excellent water protection. The only layer you, the homeowner, can safely view is the roof deck, and there you will be looking at its underside.


A trip into the attic should satisfy your curiosity. The angled timbers above are rafters; the wide expanses of wood between rafters are sheets of sheathing. Tell your roofer right away if you see discoloration, water stains, rot, or evidence of pests chewing or boring into the wood.

First Things

Since your roof deck is part of your home, you can expect it to be put in place even if you are installing a brand-new roof. If you are having full roof replacement performed, the roofing crew will tear off your old roof down to the sheathing before adding new layers. This exposes the deck so they can inspect it for rot or other water damage. Always insist on fresh underlayment and ice and water shield to give your home maximum protection.

When you trust your house to Allstate Exteriors & Restoration in central Ohio or Cape Coral, FL, your roof, home, and family are all protected. Contact us today to learn about our extensive roofing, siding, and gutter installation services.

Westerville Homeowners: Keeping Your Roof in Top Shape

April 8, 2026
Your home is more than just a place to stash your stuff; it’s the place you’ve poured your life into. Living here in Westerville, we’re lucky to have such a great mix of tight-knit neighborhoods and quick access to everything we need. Whether you’re grabbing coffee near Uptown or taking the kids to spend an afternoon at Inniswood, you know this area is special. But let’s be honest: Ohio weather isn't always kind to our houses. Between the brutal freeze-thaw cycles in the winter and that sticky humidity we get living near the reservoir, your roof takes a beating. It’s the first line of defense for everything inside your walls.  If you’ve been spotting a few stray shingles in the yard or just have a nagging feeling that your roof is getting a bit long in the tooth, you’re in the right place. As a local roofing company, we’ve been up on enough Westerville rooftops to know exactly what makes them tick, and what tends to go wrong. Why "Local" Actually Matters There’s a big difference between a national franchise and a crew that actually lives and works here. We aren’t just reading a manual; we’ve dealt with the same storms you have. The Ohio Reality Check We don’t have mild winters here. We have "ice dam" winters. When your attic isn't venting heat properly, the snow on your roof melts, runs down to the eaves, and freezes again. That cycle can force water right under your shingles and into your insulation. If you’ve ever seen water spots on your ceiling after a winter thaw, that’s usually the culprit. On the flip side, our summers can be relentless. All that heat and humidity can lead to moss or algae growth, especially on the north side of the house where the sun doesn't hit as much. If you let that stuff sit, it eventually eats away at the grit on your shingles. Matching the Neighborhood We’ve worked on everything from the historic homes with unique angles to the newer builds in the suburbs. Every home needs a slightly different strategy. A quick patch might be fine for one house, but a total re-roofing might be the smarter, cheaper play for another. We’re not here to upsell you; we’re here to tell you what your specific roof needs to last another 20 years.

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 Running a business in Beavercreek, Ohio comes with its unique set of challenges and responsibilities. One of the most critical investments for any commercial property is the roof. A well-designed, high-quality roof protects your building, employees, and assets while enhancing energy efficiency and reducing long-term maintenance costs. Understanding the best options for your property is crucial, and Commercial Roofing Solutions for Beavercreek Businesses from Allstate Exteriors are designed to meet the diverse needs of local businesses throughout Greene County. From office buildings in central Beavercreek to retail centers near Wright-Patterson Air Force Base, commercial roofing requires specialized knowledge. Allstate Exteriors combines decades of experience, local expertise, and a commitment to quality to ensure that your business receives roofing solutions that stand the test of time. Why Commercial Roofing Matters for Beavercreek Businesses Commercial roofs face different pressures than residential roofs. They cover larger areas, often have more complex structures, and are exposed to frequent foot traffic during maintenance. Weather in Beavercreek adds another layer of complexity. Summer storms bring heavy rain and high humidity, while winter conditions include snow, ice, and temperature fluctuations. Over time, these elements can degrade roofing materials if not properly maintained or installed. Investing in a professional roofing system reduces the risk of leaks, structural damage, and costly emergency repairs. It also protects your employees, inventory, and customers from exposure to the elements. A well-planned roof contributes to the operational efficiency of your business and can even improve energy performance, which is increasingly important for modern commercial properties.

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Historic Roof Care: Preserving Ashville’s Older Homes

March 5, 2026
Ashville, Ohio is a community rich with history, character, and homes that tell the story of generations. For many homeowners throughout Ashville and neighboring communities such as South Bloomfield, Tarlton, and Canal Winchester, preserving the charm and structural integrity of these older homes is a priority. When it comes to protecting these architectural treasures, Historic Roof Care: Preserving Ashville’s Older Homes is not just a service, it is a vital investment in maintaining the legacy and value of your property. At Allstate Exteriors , we specialize in delivering expert historic roof care tailored to the unique needs of Ashville’s older homes and historic districts. In the heart of Ohio, older homes were often built with materials and methods that differ significantly from modern constructions. These roofs carry years of history and have faced decades of weather, from icy winters to humid summers. Understanding how to preserve these roofs requires more than a standard roofing service. It demands a specialized approach rooted in respect for historical craftsmanship and knowledge of local conditions in Ashville . In this post, we’ll explore practical guidance, local insights, and the reasons why trusted historic roof care from Allstate Exteriors makes all the difference for homeowners committed to preserving Ashville’s architectural heritage. Why Historic Roof Care Matters in Ashville Many homeowners in Ashville are drawn to older homes because of their distinct charm, unique character, and timeless appeal. However, historic roofs often present challenges that modern roofing systems do not. Traditional materials such as slate, cedar shake, or metal roofing installed decades ago have specific maintenance requirements. The purpose of historic roof care in Ashville is to extend the life of these roofs while maintaining their original appearance and structural integrity. Historic roofs were built in an era before modern synthetic underlayments, advanced flashing systems, and today’s wind-resistant technologies. Over time, exposure to Ashville’s seasonal climate variations can cause traditional shingles to crack, valleys to weaken, and flashing to corrode. Homeowners who postpone preservation work risk accelerated deterioration, water infiltration, and costly repairs in the future. By investing in historic roof preservation , you are protecting the original craftsmanship that makes your home unique while also enhancing long-term durability and performance. At Allstate Exteriors , we take a customized approach to historic roof care that accounts for both the architectural significance of your home and the environmental factors specific to Ashville and the surrounding areas. With decades of combined experience working with historic properties, our team is well-equipped to assess, protect, and preserve roofs that others might overlook. Whether it is a slate roof dating back nearly a century or a cedar shake roof in need of rehabilitation, we provide solutions that honor Ashville’s past while preparing your roof for the future. Understanding the Unique Challenges of Historic Roofs in Ashville Historic roofs are more than just a collection of shingles or tiles, they are an integral part of a home’s architectural identity. Because of this, the process of historic roof care in Ashville begins with understanding the distinct issues these roofs face over time. Material-Specific Challenges Slate, for example, is a beautiful, long-lasting material that can endure for over a century, but individual slates can become brittle and break. Cedar shake roofs offer natural beauty and insulation qualities, but they are susceptible to rot and insect damage if not properly maintained. Metal roofs, often found on historic barns and outbuildings in Ashville, can suffer from corrosion if protective coatings deteriorate. Architectural Complexity Many historic homes in Ashville feature steep slopes, intricate gables, and architectural bezels that create aesthetic appeal but also complicate maintenance and repairs. Without careful inspection and a preservation strategy, water can find its way into vulnerable areas such as valleys, flashing seams, and chimneys. Climate Impact Local weather patterns also play a role. Ashville’s humid summers can cause wood materials to expand, while Ohio’s cold winters bring freeze-thaw cycles that stress roofing components. Heavy rains, spring storms, and strong winds can loosen historically significant roofing elements. Allstate Exteriors’ historic roof care services include proactive measures that anticipate these challenges and address them with precision and care.