This has been the most concerned question by most of the people. Many times, they are confused about placing the new shingles on an already existing shingle roof. So, the answer to this is quite simple. Yes, you can place new shingles over the old ones. By installing new shingles over the already present shingles takes less time than installing a new roof by removing or tearing off the old one. The quality of the final product is as good as the new one. They last long as well. Shingles placement over the old ones needs professional workers as it contains a lot of technical work if not done right, might get you into trouble later. And they also come with the same manufacturer’s warranty.
Things to Keep in Mind While Placing New Shingles Over the Old Ones
- Never mix materials while installing new shingles. If you are installing wood shingles on the concrete shingles this is totally a wrong match.
- The condition of the old shingles must be double checked. If they are in a good condition you can lay the new layer over the top otherwise all efforts will be in vain and of no use.
- If the areas in the old shingles are damaged, then better change them instead of laying them with the new shingles over the old ones.
- Remove the loose shingles before placing them with the new shingles and apply the new layer in that specific area of approx. 30 pounds roofing before installing the new shingles over them.
Why Add the New Shingles Over the Old Shingles (Pros)?
The answer to this is convenience and the cost that you might save from not removing the old roof. Tearing off the roof costs a lot and, in that way when you place the new roof over the old one, you save the roof tearing cost. But most of the time you are just delaying the cost because in some areas only two layers are allowed and when there is a time to change the roof due to some technical reasons then you have no choice apart from tearing the double roof and just add the new one. But the longevity of the shingle roof and durability of the shingle roofs is another advantage. They have a good lifespan if you take care of it properly and regular checking by the roofing professionals.
Disadvantages of Adding the New Shingle Roof Over the Old One
Pros and cons are the part of every roofing but it really depends on you how you take care of your roof and how you can make it durable and beneficial for you in the long run. Maintenance is the key. There are some reasons which you should take into consideration before placing the new roof over the old one.
- Required weight for the placement of the new roof over the old one:
Most of the shingles weigh around 350 to 400 pounds per square. So, considering the layer weight while keeping the margin for snow, other stuff weight and a safety margin as well. When placing the new shingles over the old once make sure that your roof can hold the new roof load along with the extra margin load of snow and other things. On some houses the extra load of roof layers causes the sheathing to sag between the rafters and trusses.
- Requirement of roof sheathing inspection:
When your roof construction is done by the professionals, they have the experience of checking the deck by just walking on the roof. But in some cases, if you have not hired the professional roofers, they can just ruin the whole work by not having enough experience of checking the deck without seeing it.
- Waterproofing of the shingle roofing:
Just by layering the new roof over the old one does not save your roof from water dripping. You must make a layer of tar paper between the new and old shingle roof to make the roof waterproof. Checking of the very old and deteriorated shingles before any installation will save your roof from getting water into the deck. Extra layers of shingles provide less protection against ice dams.
- Hurdle in warranty work:
Before installing the new layer of shingles over the old one, make sure to talk to the shingle manufacturer regarding all the warranty issues.
- Layers allowed by the local codes for placement of the new shingle roof:
Areas where there are heavy hail storms and rains or having ice dams’ problems are only allowed to have two layers of shingle roofing maximum and you can not exceed the limit by any chance.
- Cons while selling your house with double layering of the roof:
While selling your house you must tell the agency about the double layer roof. So that they can guide you better about the selling options because the buyers would be considerate about getting a house with a double layer roof.
Call for free consultation at 734-548-9911 or visit online at Downriverroofers for detailed discussion on your roofing queries.