Charleston Roofing: Article About Reroofing Over an Existing Shingle Roof
Homeowners who need to reshingle their roofs may have a decision to make on whether or not to roof over the existing shingles or to tear off the existing shingles and start fresh. There are advantages and disadvantages to both, but many professional contractors are divided on whether or not reroofing over an existing roof should be done. Homeowners who are considering a roof replacement should discuss options with their trusted Charleston roofing contractor.
A roofing overlay is where a new set of shingles are installed directly over the old set of shingles. There are certain conditions that must be met before a homeowner can choose to have new shingles installed over older ones. First, the sheathing and structural material must be in good condition. Second, the old shingles should be lying flat. If either of these two conditions are not met, the new shingles will degrade much faster than they should.
The major advantage of a roofing overlay is the cost. Because the homeowner is only paying to have the shingles installed, they are saving on the cost of having the old shingles removed and for construction debris cost.
Have a question regarding metals roofs or roof replacement? Ask a roofing contractor at Lowcountry roofing of Charleston SC.
Additionally, if the job is done correctly, the new shingles may have a comparable lifespan to the old shingles.
Roofers may prefer the overlay option because there is a lot less liability involved in the process. An overlay project will create less waste, and the chance of damage to the sheathing due to a sudden change in weather is also unlikely.
While the advantages may leave homeowners wondering why anyone would choose to tear off the roof before installing new shingles, they should keep in mind that roof overlays have some serious drawbacks. First, the roof decking is now supporting not one roof but two. This puts the decking under serious stress that could ultimately result in damage in the long run. Another problem lies with the decking and sheathing itself; if these materials have already sustained damage, this damage may not be noticed because the original layer of shingles were not removed.
Since not all buildings can handle the weight of two roofs, it is highly recommended that a contractor inspect the situation before a decision is made. If there is a possibility of damage to the underlying structure, it may be best to have the old shingles removed and new roofing materials installed. A new roof will often add value to the home whereas a simple overlay job does not.