No roof lasts forever. Even with regular maintenance and repairs, there will come a time when the wear and tear caused by exposure to the elements is just too much. You may notice leaks or missing shingles, or a roofing inspection may reveal that your roof is too far gone for simple repairs. When you reach that point, you may have to make a choice. Should you have the old roof completely torn off and replaced? Or, should you have the new roofing system laid over the old roofing system? Both choices have their own specific pros and cons. Take a look at the benefits and drawbacks of each option to decide which is right for your roof.
Many people don't realize that having a new roof installed over the old roof is even an option, but it is a choice that you may have. Whether an overlay will work for you depends on the type of roof you currently have, the extent of the damage to your current roof, and the type of roof you plan to have installed.
For example, you can install asphalt shingles over a previously asphalt shingled roof, and you can also install a metal roof over an asphalt shingled roof. However, installing asphalt shingles over metal would be impractical. Flat roofs can often be overlaid with spray-foam or cool roof coatings rather than removing the existing roof. Ideally, an overlay shouldn't be attempted if the current roof has extensive water damage. There are some significant benefits to an overlay.
- Cost. An overlay is less expensive, since you won't have to pay for the labor to tear the old roof off, or to have the old roofing materials disposed of.
- Speed. Your new roof will be completed quickly, because the roofers won't need to take the time to tear off the old roof.
- Sustainability. An overlay is environmentally friendly, because it cuts down on waste.
However, it's important to also consider the drawbacks of an overlay.
- Uncertainty. Without a tear-off, your roofers can't determine the full extent of any damage to your deck or sheathing.
- Weight. Two layers of roofing means a roof that's twice as heavy. Make sure that your house can bear the weight.
- Cost. While an overlay may be cheaper this time, the next time your roof needs to be replaced, roofers will have two layers to remove. That can cost you more.
A tear-off is the more common choice, and it involves the roofers completely removing the old roof before putting the new one on. This is done when the existing roof has such extensive damage that an overlay is impractical, or when there are already two layers of roofing and the local building codes prohibit any more layers. Also, multiple roof layers can make a home tougher to resell, and insurance companies will usually only insure the top layer, so homeowners that plan to sell their homes often choose the tear-off option. Check out the advantages of a tear-off.
- Strength. A tear-off allows the roofers to inspect your roof deck, and strengthen or replace it if necessary. This can extend the life of your roofing system.
- Watertight. A roof put in after a tear-off is less prone to leaks. This is because the roofing material is flat against the roof sheathing. Installing a new roof over the old roof means that there are more likely to be gaps that lead to leaks.
- Less Repair Costs. The more layers there are, the more likely it is that something will go wrong. By installing a new roof after a tear-off, you're cutting your repair costs down the road.
There are relatively few disadvantages to the tear-off option. The only real drawbacks are the higher upfront costs and the increased amount of time it will take to complete the work. Only you can decide whether those disadvantages outweigh the benefits in your particular situation.
If you're still not sure whether an overlay or a tear-off is right for you, discussing the matter with your roofing contractor, like those at John Criner Roofing Inc, can help. Your contractor will be able to tell you whether or not an overlay is a viable option for your roof, and can recommend a course of action that meets you needs.