When I Buy a New Roof, What Does It Include?
All Weather Roofing
If you’re like most of us, you never used to think much about your roof. It was just there, and it did its job to keep the rain out.
But now you realize that your roof is starting to fail and needs to be replaced. Your roof has pretty much reached its expiration date.
What is a roof replacement? Is it just the outside layer of material like shingles, or is there more to it?
Roof Replacement 101 – The basics.
There are two options for a roof replacement: A tear-off, and an overlay. A roof overlay means that a layer of new roofing materials is installed over your existing roof.
This article focuses on roof tear-offs. A roof tear-off is the removal of all existing layers of roof assembly materials down to the roof decking, and the installation of new roof covering materials.
The roof decking (sheathing) is a flat material that is placed on top of the rafters to provide a solid base for the roofing materials. Decking can be construction-grade plywood, compressed wood sheets (called OSB or oriented strand board), or metal sheets.
When your building was constructed, the general contractor built or installed the rafters, trusses, and roof decking to support the roofing materials, and then the roofing contractor installed the initial roof covering materials.
When you replace your roof, your roofing contractor will not usually need to replace items like rafters and roof decking (though repairs are sometimes needed if they are damaged).
Roofing system components.
When you get a new roof, your roofing contractor will usually remove and replace the following:
Underlayment: Underlayment is a water-resistant layer of material that is installed on top of the roof decking. The most common underlayment is asphalt-treated felt paper. Synthetic underlayment is also available.
The purpose of underlayment is to help keep your roof dry in the case of a weather event like a high wind that loosens the roof covering materials. Roofing materials manufacturers have underlayment specifications for each of their roof covering materials.
Roof coverings: This is part of the roof system we see and are more familiar with. Roof covering materials include asphalt shingles, clay tile, concrete tile, slate and slate-type shingles, metal roof shingles, and metal roof panels.
There are several single-ply membrane roofing options such as thermoplastic membranes (TPO), polyvinyl chloride (PVC), and synthetic rubber.
Roof ventilation: Ventilation elements provide a continuous flow of outside air and circulation to areas beneath the roof deck, such as attics and crawl spaces. Your roofing contractor will need to make the necessary calculations to determine if your existing ventilation meets the current California Building Code.
Roof drainage: Drainage systems can include gutters, downspouts, and drains. These remove water from the roof surface as quickly as possible. To prevent roof damage, it’s important to prevent water from pooling or ponding on the roof.
Flashing: Flashing is most often a thin piece of sheet metal that protects a joint in the roof from water damage, though other flashing materials are sometimes used. Flashing is used wherever there is a change in roof slope or direction, and around roof openings like vents, chimneys, and skylights.
Flashing needs to be installed according to the manufacturer’s approved instructions for the roof covering material being used.
Ridge cap: The ridge is the peak of the roof where two roof planes meet. A ridge cap is required to seal the joint. Roof ventilation is often a part of the ridge cap system.
Building codes and manufacturer specifications are important.
The exact materials requirements for your roof replacement will depend on four things: 1) the slope of your roof, 2) your preferred roofing materials, 3) the building codes for your location, and 4) the installation and product specifications of the materials manufacturer.
Your roofing contractor will verify the requirements prior to finalizing your contract for your roof replacement.
The next steps.
Now that you know the basics, it’s time to call your roofing company to schedule an estimate for your new roof.
When the estimator arrives, he will verify that your roof is at the end of its lifespan. Then he’ll confirm your roof slope and measure your roof.
The estimator will explain your options for your new roofing system, including your options for materials type, styles, and colors. After you choose your materials and decide on options, the estimator will give you a written estimate for your new roof.
Next, the roofing company will prepare a detailed contract that defines the project scope, materials, and price for your roof replacement.
Things to look for as you read your roof replacement contract.
Before you sign your roof replacement contract, be sure to read it carefully to make sure that you understand what is included, and the price you will pay.
Be sure that everything you expect to get is itemized in your contract. For example, does the price include removing and disposing of your existing roof system? Are you getting the roof covering materials you want? Are new gutters and downspouts included?
Once you and the roofing contractor or his salesperson sign the contract, the roofing company will order your materials and schedule your project.
For more information on contracts, see Roofing Contracts 101: What Every California Homeowner Should Know About Roof Replacement & Repair Contracts.
Your new worry-free roof.
Before long you’ll have your new roof. Getting a new roof can give your building a fresh, updated look that will improve its curb appeal and can increase your property value.
Your friends will be impressed.
All Weather Roofing.