What You Should Know About Roofing Replacement (2023)

The Basic Roofing Materials

Choosing roof replacement options often depends on your locality and your preference. For example, metal roofing is a standard selection in some regions due to its fire resistance. In contrast, the predominant home styles in other areas might call for a Spanish-influenced tile.Roof pitch (angle)also affectsthe roofing materials you can use. For example,wood shake shinglescan be used for steeper-pitched roofs but are unsuitable for flatter, low-pitched roofs.

The most common choices for residential roofing include:

• Asphalt composition shingles: These are cheap and easily obtainable but less attractive than other options due to their flat appearance. This roofing type is by far the most popular roofing material.
• Wood shakes or shingles:These are pricey but attractive shingles. They have excellent durabilitybut aren't a good choice in regions with fire danger.
• Metal Roofing: Metal roofs made of steel or aluminum have become more prevalent in recent years due to their durability and fireproof durability. These expensive roofs require specialty contractors for installation, but they may be cost-effective over the long run due to their long life. Several types of metal roofing systems are available, including raised-seam panels and products that mimic the look of composite shingles.
• Slate roofing:This is a desirable, high-end roofing option, but it is expensive and heavy. Slate roofs are extremely slippery to walk onand difficult to repair when damaged.
• Composition slate:These synthetic tiles made from 95 percent recycled materials, including rubber, are gaining popularity. They closely resemble slate and other forms of stone tile but are much lighter and less susceptible to damage.
• Clay or ceramic tile:Long the most predominant image in Southern California and Florida, the Spanish-style red tile roof is still common but gradually replaced by metal and composite materials that mimic the Spanish tile look. Other roofing materials that meetceramic tile's fireretardant ability are now available, with much less weight put on the roof. This type of shingle is called the "half-barrel" because it is essentially a cylinder cut in half length-wise, roughly 16 inches long.

According to the National Association of Home Builders, costlier slate, copper, and tile roofs lastover 50 years. Wood shake roofs endure about 30 years, fiber cement shingles have a life of nearly 25 years, and asphalt shingle composition roofs last about 20 years.

Tear Off or Second Layer?

It was once common to lay a new shingle roof over the preexisting layer at least once or sometimes even twice. This roofing practice is no longer allowed in some jurisdictions, where complete tear-off of the previous roofing is now required. Even where layering is allowed, applying a new layer of shingles over the old should be carefully considered based on its pros and cons:

• Weight: The main argument against laying additional layers of asphalt shingles is that the roofing materials can get too heavy for the underlying roof framing. Excessive weight can cause structural problems, especially for older houses. A triple layer of asphalt shingles is often equal to a single layer of slate shingles—an exceedingly heavy material.
• Telegraphing: Another problem with shingling over existing shingles is repeating some surface irregularities that may already be present. If you're contemplating putting on a new roof, there's probably a good chance you may have bubbles, bumps, and waves that should be remedied. Putting new shingles over existing problems can leave you with a rather unattractive new roof. One way to minimize this problem is to go over the old roof and correct as many issues as possible before re-roofing. It doesn't take much more than a hammer, some roofing nails and a handful of shingles to correct bumps, gaps, and protruding nails.
• Work and waste reduction: The primary advantage of layering is that it reduces the work involved.Stripping off the existing layer and then laying down a new layer adds more work to the process. Time isn't a problem if roofing professionals tackle the job because they can strip most roofs in the morning. But if you're doing the job yourself, it can be a strong argument for roofing over the old roof.
• Manufacturer's warranties: Some types of roofs and manufacturers require that roofs under warranty be stripped entirely to comply with the rules and restrictions of the warranty. If the roof is currently under warranty, check what the warranty requires.
  

Consider Off-Season Roofing Work

While in most parts of the United States, the optimal roofing season is from late spring to early fall, skilled crews can extend the work season, sometimes even roofing when snow flurries are threatening.

There is no reason not to hire a skilled crew to roof your home during off-season periods. You may get lower prices at these times since the labor demand is low. The trick behind getting your roof job shoehorned into the offseasonis having a large team of professional roofers who can knock out the work in hours instead of days, thus taking advantage of dry periods.

Understand the Roofing Process

If you understand the steps to replacing a roof and the jargon used in the roofing trade, you'll be able to make an informed decision when hiring a roofing crew. A moderately-sized, professionally-installed roofing job might take only three or four days.

Here's the usual process:

1. Remove all existing shingles; deposit them in a roll-off dumpster: Damaged or old valley flashing and drip edging are also removed at this time. A good crew will use tarps to protect foundation plantings and shrubs during tear-off and will use magnetic tools to pick up nails and metal objects from the lawn.
2. Make minor repairs on the roof if it is in good condition: If not, replace bad wood with new plywood sheathing or1 by 6 sheathing boards. Whichever applies to your type of roof.
3. Install ice dam protectionin regions that require it: The ice guard membrane is a synthetic waterproof barrier material designed to prevent melting ice from backing up under the shingles and penetrating through the sheathing, where the moisture can cause severe damage.
4. Lay down asphalt roofing paper over the roof sheathing: The layer of roofing paper creates an inner barrier against water penetrating the house. Rows of roofing paper are overlapped as they progress upward toward the peak and are normally tacked or stapled in place.
5. Apply metal drip edging around the roof's edge, both the eave and gable sides: The metal drip edge is nailed over the roofing paper or ice guard.
6. Where necessary, apply a new 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. Apply the tab shingles, starting at the eaves and working upward toward the peak: Where roof vents are being installed, tab shingles are installed starting from the bottom, moving upwards.
8. Apply the flashing around all areas where leaks might come into the house—against the chimney, around skylights and stack vents, etc.: Flashing installation may happen as part of the roofing installation, occurring as the rows of shingles progress upward on the roof deck.
9. Install the ridge vent: This continuous vent along the roof's peak will help the air circulation in the attic space and can be integral in exhausting hot air and preventing winter ice dams. Ridge vents may not be included on older roofs, but installing them is a good idea whenever a house is re-roofed. If ridge vents are not practical, other types of roof or gable vents should be installed to provide air circulation in the attic space.
10. Complete the final cleanup and haul the debris away: Have a building inspector inspect and approve the installation.

The roofing business uses some special terminology when estimating materials for a roofing job.

• 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.