How a roof is installed?

roof with shingles installed

Should you remove old shingles before installing new shingles?

The roof installation on your home is extremely important, so it is only natural that you want to make sure that every part of the roof installation is done correctly. So, you start by getting a few professional roof installation estimates. 

These estimates will typically be like a roof installation checklist. They should include all the roof installation materials to be used and a time frame for the length of the roof installation job. Some questions that homeowners with the first time getting a new roof include the following: 

When it comes to a new roof installation, it is expensive, and sometimes doing a repair job is the cost-efficient way to go. However, to do a repair job on a few shingles or for a full new roof installation, most contractors and shingle manufacturers advise against placing new shingles over old existing shingles. good idea. 

The reasons that roofing contractors, shingle manufacturers, even insurance companies will advise against installing new over old existing are: 

  1. Bumpy Surfaces Difficulties: Roofing shingles should have an even, flat fit. When roofing shingles are installed on a bumpy foundation with gaps, the old shingles transmit to the new shingle layer, making it difficult to secure the top layer. As the roof installation continues, it becomes harder with each row of shingles to mount and secure the new shingles. 
  2. Improper Inspections: Old roofing shingles make it challenging for future contractors to properly examine the roof. When the contractor can’t get to the base of the work, meaning the roofing deck, because of the layer of old shingles, they can’t fully determine any damage to the roof. In the future, if you decide to place your home on the market, a re-roof installation can decrease the value of your home and make selling it a challenge. How? While the re-roof installation job may look good to the naked eye, when the required inspection is done, the inspector is obligated to let the potential buyer know there are two layers of roofing. 
  3. Environmental Costs: An overlay roof installation may be less expensive at the time, but in the long fun, it can become expensive for the environment. Each year, the roofing industry is getting more in tune with manufacturing environmentally friendly materials. So, with each new roof installation, the old materials are getting more sustainable, and the future shows they will become even more so in the future. If you go with a re-roof installation instead of a completely new roof installation, it is only delaying the inevitable. The next time your  home will need a new roof, or roof repair, there will be 2 layers of old shingles headed to the landfill instead of one. 
  4. Roof Leaks: A re-roof installation will keep the roofing contractors from installing the proper leak barriers and ice dams. These are essential for a healthy roof and in many areas of the country, you don’t want to be without these two things. Without them, water will get up under the new layer of shingles, into the old layer, to the decking, and the issues get worse as the water seeps through.
  5. Weight Burden: A small roof structure cannot handle heavy, immense weight, and having two layers of roofing is a lot of weight. A second layer of shingles will increase the strain and is setting your home up for further roof and structural problems. This should be a big concern for areas that are prone for heavy amounts of snow, which adds even more weight on the roof. 
  6. Warranty Voided: Re-roof installation can negatively affect the manufacturer’s warranty on new shingles. Before any new or re-roof installation, check with the warranty offered by the manufacturer for their requirements in the warranty being honored. This is one reason many roofing contractors will refuse the do a re-roof installation. When warranties are voided, it reflects on them with the homeowner and if they are certified by a manufacturer, the risk losing that certification. 
  7. Building Regulations and Restrictions: There are specific regulations and restrictions in most geographic areas, and layers of new roof installation over an existing roof is not allowed. Cities and counties have building codes requiring the roofing contractor to have a permit and the finished job to be inspected by the local government.  

How do you install shingles over existing roof?

Okay, so you’ve been advised that a re-roof installation may cause more issues than it saves time going forward. However, there are time, when the conditions are in the right place, a roof installation of new shingles over existing shingles is what has to be done. The end results can be attractive,  and almost as durable as direct roof installation to the decking, plus the existing shingles will give you a pattern to follow. 

Take every possibility to install the new shingles as flat and snug fitting as possible.  Install new flashing, including the drip-edge, so that you have a tight seal against water penetration and give the new re-roof installation a long life. Ask the roofing contractor about installing a WSU (waterproof shingle underlayment) over the existing shingles along the eave end for ice dam protection.

shingles along a roof

How long does a 30 year roof really last?

You haven’t been told the truth about roofing shingles for years.  A 30-year shingle will give you approximately 25 years of life if you follow recommended care and upkeep. If you have a new roof installation done and not follow the manufacturer’s recommendations, then you’ll get a maximum of 15 years lifespan.

Almost every home will need a new roof installation sooner than later, that is almost as certain as you’ll need to pay property taxes. However, you will get much less lifespan from a roof if you don’t perform the recommended maintenance. This includes professional roof inspections at least once a year, in some areas, twice a year is recommended, and monthly inspection by you with routine gutter and roof cleaning. 

So, as you choose shingles for your new roof installation, what are the longest-lasting roof shingles? Knowing this will certainly lengthen the time out before you’ll need to budget this project again!  The longest lifespan roofing material you can choose is clay, concrete, or slate tiles. Compared to asphalt shingles, wood shakes, or other natural roofing material products, you’ll get a longer lifespan as long as you don’t experience any roof installation issues or side-step the recommended maintenance. Get started on your roof installation in Erie and Denver, CO today. Call (303) 647-3883.