
So you’ve decided to replace your roof. Maybe because it is beyond repair. Is it because the roof is past its useful lifespan? Or maybe you’re planning on moving and you know that replacing your roof will increase your house’s sale value. Regardless of how you got here, you still have another important question. Should you shingle over the existing layer or tear off the existing roof and install the new one directly to the roof’s deck? In many ways this is a question of now verses later. Learn which camp you fall into, and the pros and cons of either choice of roof replacement solutions.
Roofing Over an Existing Roof
If your roof’s shingles aren’t in utter shambles, placing another layer of shingles down over them is an option. It isn’t advisable to shingle over the old roof if there’s a lot of:
- Warped shingles
- Mildew, moss, or fungal infestation
- Significant structural damage,
You need to remove the trouble spots to keep your roof safe and level.
However, if you’ve got an okay roof with a bit of wear, you can save some time and money by putting another layer over them. There is a catch however: International Residential Code.
R907.3 of the International Residential Code is the standard that all US buildings must be built to. It covers new roof coverings on top of existing layers of roofing. Besides the point outlined above (deteriorated roof coverings), you can’t put down another layer of shingles if the existing roof has two or more applications of existing roof coverings (shingles). So if you’ve already roofed over once, you can’t do it again.
Tearing Off the Existing Roof
While roofing over has the distinct benefit of being the quicker and cheaper roof replacement option, it is potentially putting a band-aid over a larger problem. Once you’ve got that second layer on, you’ve got twice the roofing issues that could crop up. First, you have twice the weight on your roof (it’s one of the major reasons for the R907.3 code), and that can be the tipping point for heavy rain to cause serious damage. The second is that if a problem occurs (such as a leaking roof) you’ve got twice the shingles to work through to find the source of the problem. In addition, it’s a longer time before you can check the state of your roof deck.
Here are a few reasons why you should replace your roofing system, rather than covering it up:
Mold & Decay
One of the biggest reasons to replace, not cover up your existing roof is because of the mold and decay that could be present on or around your present roofing system. During a full roof replacement, all of the old roofing system is torn off, disposed of and then replaced with a completely new roof.
If your new roof is installed over your old roof, you not only run the risk of keeping any existing mold and decay around, but also of further promoting its growth. If there is moisture present on or under your old roof, covering it with a new layer essentially traps the moisture. This can aid the growth of any mold and cause your roof to decay even faster, leading to expensive repairs.
Avoid Covering Hidden Damage
Whenever your roofing contractor tears off your old roof to replace it with a new one, they get a chance to inspect your entire roof for any damage. This includes holes, decay, insect problems and more. By taking care of this step before covering your roof with new materials, they are able to identify and solve any problems before they spiral out of control.
Choosing to cover up your existing roof can perpetuate and hide potential issues of roof integrity and damage. You are left with more pressing, expensive and extensive repairs than if you had tackled the problem from the start.
Increase the Life and Quality Of Your Roof
Naturally, allowing your roofing contractor to properly install your roof can lead to a better overall experience, including a longer lifespan for your new roof. Roofs that have been completely replaced:
- Lay more evenly on the decking of your home
- Are subject to less moisture issues
- Just look better than roofs that have been layered on top of each other.
Checking Your Roof Deck
Your roof deck and roof felt support all the shingles and flashing above. Damage on their part can lead to a roof disaster. By peeling back to the deck, it gives your roofers a chance to check on its state. Wood rot and damage or poor installation of the felt nails or screws can spell big costs down the line. In the long run, a tear off can save money.
Want to know which option is right for your roof or if your roof can be repaired instead of replaced? Contact All Weather Title and our professionals can provide a free estimate for and help you decide.
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