You may realize you need a new roof when rain leaks into the attic. All of your mementos will get moldy and you will lose cherished photos of your children growing up. Continued leaking causes wood supports to rot as well.

First of all be aware of how long your roof is likely to last. Here is a rough idea for various roofing materials.

  • Tile, slate, copper roofs: 50 years
  • Wood shakes roofs: 30 years
  • Fiber cement shingle roofs: 25 years
  • Asphalt shingle roofs: 20 years

If you experience a leak or if a severe storm causes obvious damage you know you have to replace the roof. But if nothing dramatic happens you should look for curled, cracked, or severely discolored shingles. And a trip into the attic to check for signs of water leakage is a good idea.

How to Replace a Roof

You have decided the old roof has run its course. What do you do first?

Roofing Materials

Now is the time to decide if you want a roof that will last half a century or 20 years. If your home will stay in the family for many decades you may choose a more expensive approach with a copper, tile, or slate roof. If you plan to move in a few years the more economical route of asphalt shingles may work out just fine.

Strip the Roof First or Lay New Shingles over the Old

It is possible to leave the old asphalt shingles in place and simply put new shingles on top of the old ones. There are two problems with this idea. First of all, you are adding more weight to the room which may be a structural problem. And your old roof may me warped and uneven. Removing the original shingles will make it easier to spot and fix problems. And the final job will look better if you have fixed a bowed area of the roof.

Have a Budget and Negotiate a Price

Before you get too far into the project you need to decide if you are doing the job yourself or having a team of professionals do it. You will not be paying a roofing contractor so you will be saving on the money you would have paid them. But, you may end up taking time off work to get the job done before the fall rains start or simply to complete things between summer rain storms. Take account of what you may lose in time off work when figuring your costs.

And talk to more than one roofing contractor. These folks have a lot of leeway in how much they charge so if one price seems a bit high, ask for another quote.

Basic Steps to Replacing the Roof

The actual work of how to replace a roof starts with removing shingles. Then you want to make needed repairs including the replacement of damaged boards. If you live up North where it snows a lot you probably want to install an ice dam. Then install the asphalt underlayment. Now you can lay shingles and caulk around vents.

When laying asphalt shingles start in the lower left-hand corner and work to your right and up. Make sure to install flashing in valleys and around chimneys and vents.

Use all of the shingles in one bundle before going on to the next. That way if there are slight color variations from bundle to bundle you will not have a checkerboard appearance to your roof.

At the valleys and rakes use full-size shingles and not anything less than 4 inches. When doing the ridge cap always attach with two nails each. Use longer nails for the ridge, one and three-fourths or two inches.

More than Laying Shingles

Do not lay new shingles over a bad roof. When you strip the old shingles take a good look and make sure to replace rotten or warped wood. Drive in new nails where needed. And if old flashing needs to be replaced do that before starting to lay the shingles. Be sure to nail through shingles along the nailing line. Use four nails per shingle unless you live in an area with high winds in which case use six nails.