How Much Does it Cost to Install a Roof?

Roofs perform such an essential function that "keeping a roof over your head" is synonymous with the very concept of shelter. Roofs not only keep the rain off your head, they also keep moisture from destroying your home. So when it comes to maintaining your investment, the smartest money you spend could be on a new roof. How much you'll spend will vary, depending on several factors.
Size of Your house
The single largest factor in the cost of your roof is, not surprisingly, the size of your home. The bigger the house, the bigger the roof, the larger the cost of both materials and labor. Most roofers charge by the square foot, with a number that encompasses both materials and labor. Most roofers can give you a ballpark estimate of the project cost based on your home's square footage. That makes comparison shopping for roofers fairly easy.
Height and Pitch of Your Roof
The higher your roof and the steeper the pitch, the more expensive your roof installation will be. With a steeper and taller roof, the installation is both more difficult and more dangerous, and it may take longer and cost more. Some roofers will quote you a general price based on the size of your home but will not guarantee that price until they see the height and pitch of your roof and whether you have any hard-to-reach spots.
Removal of Old Shingles
If you're replacing the roof on your home with a new roof, your estimate might need to factor in the price of removing your old shingles. In some cases, you can save money by installing the new shingle over the old ones without removing them, but that's not always an option. A new roof installed over the old one can become too heavy for the structure of the house and is not always a good idea for every home. And if there are already multiple layers of shingles on the roof, not only is it a bad idea to install more shingles on top, but you may pay double the standard cost of removal.
Type and Quality of the shingles
Asphalt and composite shingles are some of the most affordable, easy-to-install, durable and long-lasting roofing materials you can use. Clay tiles, which create an Italian or Spanish style, are more expensive, but they look great and provide effective protection against fire and insects.
They can be made with organic or fiberglass materials. Fiberglass shingles tend to provide better fire protection, but both types can be waterproofed and should effectively protect against mold and mildew. Wood Shake create an attractive look, but they can present a fire hazard. Cement or concrete roofing can create the look of wood or ceramic tile without most of the drawbacks. And metal roofs, though more expensive than most other options, provide unparalleled strength and durability.
Within each of these types, you'll find different levels of quality and corresponding prices. It will almost always pay in the long run to splurge on the highest quality you can. It will last longer, protect your house better, and you might actually lower your insurance premiums. (Ask your agent.)
Gutter and flashing replacement
It may be a financially smart decision to pay extra for having your gutters and flashing installed or replaced along with your new roof. If your roofer is already doing the labor for the roof installation, the cost for gutter and flashing installation would be less than if you had them done at a later date all by themselves. So although your total costs will be higher, you will save money over doing the two jobs separately.