Roof replacement is an expensive business, but it’s often performed needlessly. In this article we’re going to lay out the arguments for full roof replacement versus timely repairs. Most people don’t know much about how their roof works, so when they discover the roof is leaking, they can be at the mercy of roofing contractors who will sell them a new roof whether that’s the best solution for the problems found or not. Here are some signs your roof should be replaced. If you don’t meet any of these conditions, it makes more sense to begin a conversation with a reputable roofer about repair options to fix the roof leaks.
Roof Replacement Signs
1. Your roof is more than 80% into its designed lifespan
The design of your roof and the materials used to construct it dictate its lifespan, which is the number of years’ service it will provide before it needs to be replaced. Typical roofs with standard construction give 25 to 30 years of service before that needs to happen.
A reputable roofing contractor will inspect your roof and estimate its age. If it’s at 80-85% of the designed lifespan they will likely recommend a new roof rather than throwing money into repairs. An asphalt shingle roof will provide 25 years of service with proper roof maintenance.
2. Extreme Weather Events have occurred in your area
If your roof has been subject to hail, fallen tree limbs, straight line winds, tornadoes or hurricane borne rain and wind you may very well have damage that will require a full roof replacement.
If you have home insurance, this type of damage is almost always covered by the insurer. Find a roofing contractor who will work with you and your insurance company to get the work done. Some contractors work directly with the insurer, while others ask you to be the interface with those folks. Insurance claims can take time to resolve but they usually result in a fairly easy process that will bring you a new roof for the cost of your deductible.
3. Your existing roof was improperly designed or installed
This is a big one and there’s often no recourse to the roofing company who installed the roof. Premature roof failures can happen if the installers didn’t apply adequate ventilation for the attic, didn't accurately set their nail gun pressure for your shingles and substrate, or if underlay material like 'Ice & Water' protection wasn’t installed far enough up the roof to prevent moisture ingress from standing roof water.
Unfortunately, poor or incompetent roof installation will always lead to premature failure and require roof replacement long before it’s technically required.
The bottom line here is if your roof doesn’t fit into either of the three modes above it will likely benefit from repairs rather than a full roof replacement. In all cases, find a reputable, local roofer to inspect your roof and give you the low down on how you should progress.
Ok, let’s assume you do need a full roof replacement and take a deeper look at what you need to know.
The Elements of a Residential Roof System
You might wonder why we need to go through each of the components of the roofing system in an article like this. The main reason is to acknowledge that each part has its own contribution to make and it’s their combination that determines the overall quality of your replacement roof. A roof is an investment and it’s important to look at the long-term benefits of using the best materials and components you can afford. Most people never regret owning a roof that cost a bit more to allow the best components to be used, but there are plenty of homeowners who wish they hadn’t gone with the cheapest quote they received.
Roof Decking
The wooden boards that form the surface, or substrate of the roof are a major component in the mechanical strength of the building. They are typically 7/16-thick ODB (Oriented Strand Boarding) and form the base your shingles and other roof components will be installed on. In most cases the existing roof decking is not replaced during a roof replacement, but if some of it is damaged due to water penetration or wind, your contractor will need to cut it out and replace the affected section before proceeding. Always inspect the bare roof decking with your contractor after the old shingles have been removed so any issues can be pointed out or questions answered.
Roof Underlayment
This plays a vital role in the overall quality of the roof. There are three main types of materials used.
- Synthetic: Known for its resistance to mold and water, synthetic underlayment is light, easy to work with and is becoming increasingly popular.
- Self-adhered: This sticky backed material is the best option when there is a chance of persistent water underneath the shingle layer during the year. It is especially effective at sealing water out of the home when ice dams form on roofs. See our article on why a self-adhered underlayment called Ice and Water is essential for homes in Michigan. Other areas of the roof that should have a self-adhered layer of underlayment include the eves, rakes and valleys, and around chimneys and skylight windows.
- Felt: Felt is an older underlayment material, also known as Tar Paper that many contractors still use today. It is still an effective moisture barrier with a long track record. It’s available in two weights 15 lb & 30 lb and is the cheapest underlayment available.
Be very wary of cost cutting at the underlayment stage. A good roofing contractor will not put you in a position where you have to choose between the right materials for the job and the costs. Don’t be surprised when a roofer who knows his stuff stands his ground and argues the point that it is much better to spend a little more money at this stage and perhaps find savings later in areas where it makes more sense. In Michigan for example, make sure the Ice and Water layer is installed to 6 feet beyond the eves, not 3-feet as is commonly performed, to virtually eliminate water leaks during a heavy ice dam year.
Building Codes for Starter Shingles
Some building code freedom is given to the contractor with regard to roof underlayment layers; there simply has to be at least a felt layer. When it comes to the first shingle layer placed on the roof however, codes across the country are clear. “Starter strips prevent shingle blow off by adhering the field course and the starter course together with a strong adhesive." (from national building code 590.1). High winds can easily lift the first shingle layer and will cause extensive damage if the shingles are allowed to lift freely. The starter shingle is a polymer bitumen adhesive layer that comprehensively binds the roof base to the first layer of shingles. Make sure your contractor is going to use an adhesive starter shingle layer. CertainTeed warranties their shingles for up to 130mph winds with the use of their suggested SwiftStart starter shingle.
Roof Flashing
One of the most consistent failure points on a roof are the flashings and boots used to seal around roof intrusions. The major reason for this is simple wear from a life in the sun and elements. In the lifespan of a 30-year shingle roof, the rubber boots around extrusions like sewer vents will fail if not replaced with a new installation. These flashings cost less than $20, but some roofers do not replace them. Worse still, a failed boot nobody notices eventually shows up as water leaking into the bedroom or the kitchen and can cost many thousands of dollars to repair.
The general rule should be If you specify a 30-year roof life you should specify the Flashing components to the highest level too. There are many metal, plastic and silicone products on the market that cost between $20 and $75 which will save the cost of the replacement visits every decade, and most importantly, keep the water out for the life of the roof without additional maintenance around the intrusion.
Other flashing components include the Drip Edge which prevents surface tension from allowing water to run along the soffit area and down the siding, Roof Flashing which covers every flashing style where the roof butts against a wall or adjacent roof, and of course Chimney Flashing. See our notes on this complicated subject here.
Attic Ventilation
The final element anyone replacing a roof should understand is the importance of ventilation in the attic. If the attic has little or no airflow it presents a great breeding ground for mold and mildew. At a minimum the roof must have vents at the eves and on the ridgeline. These days it’s common to add air vents at strategic locations along the roof surface itself. At Tresnak Roofing we use the Lomanco DeckAir product to do exactly that. These are especially useful for keeping winter attic temperatures even across the whole house, greatly reducing the chances of ice dam formation. In summer they provide more spaces for warm, moist air to escape quickly, helping prevent mold growth.
Talk to your roofing vendor about adding additional roof vents and save money on future repair bills by bullet proofing your attic ventilation.
Choosing a Roof Style or Roofing Material
The most important decision you’ll make about your new roof (other than choosing Tresnak Roofing to install it!) is the roof style and roofing materials used to create it.
There are many roof styles to choose from, many of which are constrained by budget. As usual, the more you want to spend on your roof the more options you have.
The main items that should be front of mind during this process are:
- Your overall roof replacement budget
- The importance of Curb Appeal to you and your family
- The desired lifespan of your new roof
Asphalt Roofing
The most popular roof system in America is made using asphalt shingles. Its obvious advantages are its affordability and the fact it is easy to install and repair. It is typically easy to obtain a prorated lifetime warranty for this roof.
On the downside it is very common in every neighborhood in the country, so it’s hard to generate any type of unique curb appeal. Asphalt roof owners should also commit to a yearly maintenance checkup to ensure any wear or damage is taken care of.
Within the asphalt family there are four types of shingle available.
- The 3-tab Asphalt Shingle has 3 tabs on each shingle strip and it will last for 15-20 years at a cost of around $4.00 per square foot. This is an excellent low-cost roof option.
- Architectural Asphalt Shingles add dimension to the look of the finished roof because of a random pattern on the shingle which simulates the look of a wood shake roof. It will last at least 25 years and cost approximately $5.86 per sq. foot. A home with an architectural shingle roof tends to stand out from its regular asphalt neighbors.
- Luxury Asphalt Shingles are for you if you’re looking for maximum curb appeal in the asphalt family. They offer the highest quality and are larger than the other asphalt shingle options. Warranty and lifespan are the same for the architectural version with a cost of $7.50 per square foot.
- SBS Shingles (Styrene-Butadiene-Styrene) have a similar look to Dimensional shingles but are made with an SBS modified asphalt formula that provides rubber-like flexibility for greater weatherability and impact resistance. Many insurance plans offer discounts for using this type of shingle because of these properties.
Thanks for reading this far. We’d be delighted to provide a roof replacement estimate for using any of these build options. Your cost estimate can be determined quickly and easily using the Tresnak Instant Roof Quote tool.
