Some homeowners or contractors will install a new layer of shingles over the old one to save time or money.  Most roofing contractors do not recommend this for several reasons.  In some areas building codes don’t allow this. The homeowner or contractor should always check with the city, township, etc. before installing shingles over old ones.  By not removing the old shingles, the contractor cannot see if there are other problems underneath such as rotten or missing wood.  Removing the old layer also allows access to install new protective membranes to keep the roof watertight.  Shingles installed on each other often tend to buckle.  Doubling the roofing layer adds significant weight that the roof structure may not be designed to withstand.  While not removing the old layer may save time and money initially, the lifespan of the roof is drastically reduced and will need to be replaced sooner.  Most roofing manufacturers will not cover warranty claims when their materials are installed over old.

Craig Gouker Roofing has been installing quality residential roofing in South East Pittsburgh since 1991 and is the expert in shingle roof replacement.
www.craiggoukerroofing.com     (412)664-7679

For more information on purchasing a new shingle roof.  Check out our Roof Replacement Buyers' Guide on our Resources Page.

Every manufacturer's warranty is different  Some may pro-rate.  Others may have more limitations and exceptions.  It is important to know your warranty details before doing anything that affects your roof.

I have identified some common ways people void their warranty.

Incorrect installation.  Manufacturers have requirements as to how their materials are installed.  A contractor must use the correct tools, fasteners, and procedures.  They also must be sure they are installing the roof over decking that meets their standards.  Installing flashing incorrectly or using the wrong material can void a warranty as well. Finding a contractor certified or recognized by the manufacturer goes a long way to avoid warranty issues due to installation.

Skylights, Satellite Dishes, Solar Panels.  Installing these additions to a roof require drilling into or penetrating the roofing surface.  Doing so  may void your warranty in full or in part regarding leaking.

Improper ventilation.  A roof installation that doesn't include proper ventilation can void a warranty.  If a roof is not ventilated, moisture can be trapped inside.  It can also cause heat to build up causing premature shingle wear.

Roof designs vary greatly from low-slope to steep-pitch and any number of sides.  Each has their own challenges.  It is good to know what style roof you have.

Flat Roof - Just as the name suggests, a flat roof is just that.  Uncommon on residential buildings, flat roofs are the most commonly found on commercial structures.  They are prone to leaking since water does not quickly flow off the roof.  Heavy snow will sit on the roof and cause collapse.

Lean-to/Shed Roof - Simply one side with a slope, with varying pitch, this type of roof removes water quickly.

Gable Roof - This is the most common roof in residential construction. Most gables are between 4/12 and 8/12 pitch with the ridge across the center.

Hipped Roof -  A Hip roof has 4 sides and one ridge.  This style carries water quickly to the edges and provides good wind protection.

Gambrel Roof - This is similar to a traditional barn roof.  It has sides with different pitches which allows for more interior space.

Mansard Roof - This roof has steep side slopes and is flat on top. Often this roof has a second floor under the roof with dormers. Dormers are interruptions in the roof used to get windows into roofs. Normally this is done on a sloping attic area to increase standing room for bedrooms and to permit light or views

Cross Gabled Roof - This style roof has two or more gables that intersect creating a more interesting look.

Cross Hipped - For a cross hipped roof, the two hip roofs are laid out perpendicular to each other.


Craig Gouker Roofing has been installing quality residential roofing in South East Pittsburgh since 1991 and is the expert in shingle roof replacement.
www.craiggoukerroofing.com     (412)664-7679

The quick answer to that question is.... It depends.

How much value a new roof can add depends on the condition of the old roof.  The more the improvement the more value it will add.  Further upgrades add more.  Architectural style shingles will add more value than traditional styles.

A new roof can add value in other ways.  Is the new roof energy efficient?  An energy efficient, properly insulated roof can reduce energy bills.  The roof will also mean fewer repairs and maintenance costs to you.

If you are selling your house.  A new roof will add curb appeal attracting more potential buyers.  Some buyers are willing to pay more for a home with a new roof that was installed by a professional roofer.  They know it won't need to be replaced in the near future.  A home inspector will recognize that it was installed properly and since most warranties transfer to the new homeowner that will give them peace of mind.

To get an idea of the value a new roof can add look at your neighbors homes.  Do they have a new roof?  What is the value of their homes?  

The best way to get an accurate value of your home is to speak with a Realtor and get an appraisal.

Craig Gouker Roofing has been installing quality residential roofing in South East Pittsburgh since 1991 and is the expert in shingle roof replacement.
www.craiggoukerroofing.com     (412)664-7679