A Guide to Roof Replacement Basics

Among all major home repairs, installing new roofing is perhaps the most important. If you’re replacing a roof, you have a lot to think about, but you shouldn’t let an old roof fail; water can ruin everything from the attic insulation to the kitchen to the basement family room with the big-screen TV. A failed roof is one of the few home problems that can be more disastrous.

Roofing replacement is not a repair to put off, nor is it something you should delay. 

In the event that one shingle is damaged, it’s a good idea to have the whole roof inspected in order to determine whether the rest of the roof is intact.

Depending on the size of the area and the type of repairs, you may also need a permit to repair a roof. Permits may also be required when reroofing. Before getting bids from roofing contractors, brush up on these basics when your roof appears to be nearing the end of its useful life.

The Basic Roofing Materials

It is important to consider your locality and personal taste when choosing your roof replacement option. The fire resistance of metal roofing, for instance, makes it a popular choice in some regions. There might be a need for a Spanish-influenced tile tool in other areas. Your roof pitch (angle) also determines what roofing materials you can use. 

A steep-pitched roof can benefit from wood shake shingles, but a low-pitched roof is not suitable for them.

The most common choices for residential roofing include: 

• Asphalt composition shingles are cheap and easily obtained, but they lack the appeal of other options due to their flat appearance, which makes them less appealing than other choices. There is no doubt that this type of roofing is the most popular roofing material on the market.
• Wood shakes or shingles are a costly but attractive type of roof shingle. While they are very durable, they aren’t the best choice in areas prone to fires. 
• Metal Roofing : Steel and aluminum roofs that are made from steel and aluminum have actually become more popular in recent years as a result of their durability and fireproof properties. It may be necessary to hire specialty contractors at first to install these expensive roofs, but due to their long lifespan, they may turn out to be cost-effective in the long run. There are a number of types of metal roofing systems available on the market, such as raised seam panels and products that mimic the appearance of composite shingles. 
• Slate roofing is an expensive and heavy option, but it is a desirable, high-end roofing option. It is extremely slippery to walk on slate roofs, and they are difficult to repair if they are damaged. 
• Composition slate: Rubber and recycled plastic materials are used in the manufacture of these synthetic tiles. In many ways, they are similar to slate and other stone tiles, but they are much lighter and more resistant to damage.  
• Clay or ceramic tile: It is still common to see so-called Spanish-style red tile roofs in Southern California and Florida, although they are gradually being replaced by metal and composite materials that mimic the Spanish tile look. Other roofing materials can meet ceramic tile’s fire retardant ability without adding much weight to the roof. The “half-barrel” shingle is essentially a cylinder that has been cut in half length-wise, about 16 inches long.

According to the National Association of Home Builders, slate, copper, and tile roofs are more likely to last for more than 50 years. There is approximately a 30-year life expectancy for wood shake roofs, about a 25-year life expectancy for fiber cement roofs, and about a 20-year life expectancy for asphalt shingle composition roofs.

Tear off or Second Layer?

Overlaying a new shingle roof at least once, or sometimes twice, was once common practice. 

Some jurisdictions no longer allow this roofing practice, which now requires complete tear-off of the previous roof. It is recommended to carefully consider the pros and cons of applying a new layer of shingles over the old, even where layering is allowed: 

• Weight: There are several arguments against laying additional layers of asphalt shingles, including the fact that the materials can be too heavy for the framing beneath the roof. Older houses are particularly susceptible to structural problems caused by excess weight. Asphalt shingles are often heavier than slate shingles, which are extremely heavy.
• Telegraphing: When you shingle over existing shingles, you also repeat some surface irregularities that may already be present. When putting on a new roof, there’s probably a good chance that there are bubbles, bumps, and waves that need to be repaired. You might end up with a rather unattractive roof if you install new shingles over existing problems. Prior to re-roofing, you should go over the old roof and correct as many issues as you can. To fix bumps, gaps, and protruding nails, you only need a hammer, some roofing nails, and a handful of shingles.
• Work and waste reduction: A major advantage of layering is that it reduces the amount of work involved. The process of removing the existing layer and laying down a new layer involves more work. Roofing professionals can strip most roofs in the morning, so time isn’t an issue. Nevertheless, if you’re going to do the job yourself, you may want to consider reroofing over the old one. 
• Manufacturer’s warranties:Manufacturers and some types of roofs require that roofs under warranty be stripped completely to comply with the warranty’s rules and restrictions. Check the warranty requirements if the roof is currently covered by one.

Cost Considerations

Depending on the roofing materials you choose (ranging from cheap three-tab asphalt shingles to architectural shingles or even slate), you’ll have to pay a different amount for replacing a roof in your state. Other factors affecting the cost of a new roof include your choice of contractor, the pitch (steepness) of your roof, and its square footage. 

A three-tab composite roof for a small house can be installed for as little as $7,000. A typical roof replacement with architectural asphalt shingles costs between $3.50 and $5.50 per square foot, which includes demolition, permit fees, waste disposal, and cleanup. 

Typical average costs of different roofing options: 

• Three-tab asphalt shingles: $7,000 to $12,000
• 30-year shingles: $9,000 to $15,000
• 50-year shingles: $11,000 to $20,000
• EPDM rubber: $8,000 to $14,000
• TPO or PVC membrane: $10,000 to $15,000
• Wood shingles: $14,000 to $25,000
• Steel shingles: $14,000 to $25,000
• Aluminum shingles: $15,000 to $28,000
• Standing-seam steel roofing: $23,000 to $30,000
• Natural slate: $25,000 to $50,000
• Concrete tile: $20,000 to $40,000
• Clay tiles: $25,000 to $50,000

Consider off-Season Roofing Work

You pay a roofing company to do your roofs because a well-coordinated team is incredible to watch. Skilled crews can extend the work season beyond late spring to early fall in most parts of the U.S., even roofing when snow flurries threaten.

Therefore, you don’t need to wait until the season opens to hire a roofer. Labor demand is low at these times, so you may even enjoy lower prices. To get your roof job done in the offseason, you need a large team of professional roofers who can complete the work in hours rather than days. 

Understand the Roofing Process

Understanding the steps involved in replacing a roof, as well as the jargon used by the roofing industry, will help you make informed decisions. 

It may take only three or four days for a moderate-sized, professionally installed roofing job to be completed. As a general rule, the roofing crew follows the following process: 

1. Remove all existing shingles: At this time, damaged or old valley flashings and drip edging are also removed. During tear-off, a good crew will protect foundation plantings and shrubs with tarps and use magnets to pick up nails and metal objects. 
2. In good condition, make minor repairs to the roof. In bad condition, replace bad wood with plywood sheathing or 1 x 6 sheathing boards. Depending on the type of roof you have. 
3. Protect your home from ice dams in areas where they are necessary: Ice guard membranes are synthetic waterproof barriers that prevent melting ice from backing up under the shingles and penetrating the sheathing.
4. Asphalt roofing paper should be laid over the roof sheathing to create an inner barrier against water penetration. Roofing paper is normally tacked or stapled in place as it progresses upward toward the peak. 
5. Metal drip edges are nailed over the roofing paper or ice guard around the edges of the roof, both on the eaves and gable ends.
6. Whenever necessary, install valley flashing along with areas where two roof planes meet: The valley flashing is typically nailed to the roofing deck and sealed with roofing caulk.
7. The tab shingles are installed from the bottom up, beginning at the eaves and working toward the peak.
8. In addition to the chimney, flashing should be applied around skylights, stack vents, and other areas where leaks may occur. As the rows of shingles progress upward, the roof deck is covered with shingles. 
9. By installing a continuous vent along the ridge of the roof, you can increase air circulation in the attic space and prevent winter ice dams. An older roof may not have ridge vents, but they should be installed whenever a house is re-roofed. For attic ventilation if ridge vents are not practical, other types of roof or gable vents should be installed. 
10. Ensure that the installation has been inspected and approved by a building inspector before completing the final cleanup and hauling away the debris.

A roofing contractor uses some special terminology when estimating materials. 

• The term “square,” when used in the roofing business, is a unit of area. One square equals 100 square feet.
• Shingles come in “bundles.” Three or four bundles of shingles typically will cover a square of roofing area.