How to Replace a Roof

Jeffrey Anderson | Improvement Center Columnist | December 13, 2011

Asphalt shingles are an attractive and economical roof covering, but unfortunately they don't last forever. If you've lived in an asphalt shingled home for many years, there's a good chance the day is approaching when you'll need to start thinking about installing a new roof. A roof replacement isn't complicated, but the first question before getting started is who's going to do the work--you or a professional roofing contractor?

Roof replacement considerations for the DIYer

Many homeowners consider themselves to be competent DIYers, but that's easy to say when you're standing on terra firma. Working on a sloped surface 20 or 30 feet above the ground offers a very different perspective and isn't for everyone--even seasoned construction workers sometimes turn down jobs when they're up that high. The law of gravity dictates that being on a roof can be dangerous--even with proper safety gear.

Another reason to consider using a qualified roofing contractor is that improperly installed shingles can begin to leak and may lead to extensive water damage over time. The $45 to $65 per square that a roofer may charge to install your shingles could end up being a bargain when compared to the thousands of dollars of repairs a roof leak can cause.

New roof replacement tips

If you've decided you're not afraid of heights and have confidence in your DIY abilities, here are a few tips for installing your new roof:

  1. Quantities. Shingle quantities are figured in "squares" which are the number of shingles needed to cover 100 square feet of roof area. A roof area of 4,000 square feet would require 40 squares of shingles--remember to add a few bundles to account for waste when ordering.
  2. Shingles. There are many styles and colors of asphalt shingles to choose from. Shingle warranties range from 20 years to 50 years or longer--shingles with longer warranties are usually better and also more expensive. Economical asphalt shingles can start around $55 to $65 a square, and costs can range over $100 a square for higher end shingles with longer warranties.
  3. Strip down. In many cases it's possible to install your new roof right over the old, but you may be covering problems that have already been hiding. Removing the old shingles and felt takes a little longer and may cost a bit more, but it gives you a chance to inspect your roof sheathing for potential issues that should be corrected.

You should always inspect all roof flashing and caulking when installing new shingles and replace or repair as needed to help keep the interior of your home dry during even the most inclement weather.