1. There are some areas which may have leaks (or had) and because of the current damage, they aren’t always “tackled” appropriately.
When you need to replace a roof, especially an old roof, there may be leak spots and some old material that may be looking as if it’s disintegrating. You may not even notice it. You may need to remove it in order to see where the roof problems are. Replacing it is the easy part, looking for the problems is the difficulty in this type of work for a roofing contractor.
2. With wooden tiles or rooftops, it will only worsen because the rooftop could be rotting underneath and so can the structure underneath it.
Identifying and replacing those rotten roof tiles, or rooftop, is easier to do when you have your roofing contractor take everything out in order to assess the damages. It can be located once they have done this. The best thing to do is replace the entire roof. When a contractor replaces the roof by layering it with a new one, this only “candy-coats” the problem. In other words, the shingles in the areas which are being replaced will not hold up if you just “layer” it with more shingles covering the problem. As a matter of fact, they can easily blow off if there’s a rainstorm or a hurricane.
3. Eaves, rakes and valleys need special treatment
This can be dealt with easier when your roof is getting that special attention. While your roof is being installed, the eaves, rakes and valleys of the house is going to see a big difference because of this special attention.
There should be a 3 foot wide ice and water barrier which should prevent any type of “attack from Mother Nature” such as when the colder climates are likely to take place. Places such as Northern Illinois, or Massachusetts, is torrential when it snows. Ice builds up and when it freezes, it will eventually melt and thaw out on your rooftop. This can occur throughout the seasons of spring and winter. All in all, the roofing contractor you hire will need to put “aluminum drip-edge” around the perimeter of the roof.
On a lay-over type of roof job, the contractor will need to rely on the existing materials your rooftop has. There reasons of how you can handle your rooftop work when your contractor works on it. First of all, the materials may fall short of it’s quality and they could’ve of already outlived the warranty or it’s lifetime. Also, they may need to rely on the existing barriers your rooftop has currently. Although, with ice and water barriers, sometimes they were never installed. So, it’s good idea to let your contractor know that this was the case if they are relying on the materials of your rooftop to begin with.
4. Extra roofing weight is no good for old rafters
One of the more obvious problems with a lay-over re-roof is the added weight of the extra layer of shingles.
It’s common sense that there will be added weight to the existing layered roof shingles or tiles. Newer homes will not have this issue since most of the rooftops are all new.
There are framing standards and with the older homes, they have rafters. There may be smaller in size and to see a 2×6 rafter system on these houses is very common. The newer ones are using 2×10 and 2×12 rafters.
5. Roof life expectancy is shorter
Responsible roofing contractors will suggest that the lay-over roofs do decrease the new roof’s lifetime. This particular lifetime is by 25%. In fact, it’s considered a short term savings if you do pay for a “lay-over” rooftop instead of a new roof installation or
“tearing out the old one” method. Plus, with 2 layers of a rooftop, the next time you have to do this again, there will be more work for the contractor, meaning there will be more of a charge.
The best thing to do when re-roofing is to tear-off the old one.
These are the 5 very good reasons why you should tear off the old roof before installing the new one. Naturally, homeowners will want this done because it’s cheaper. In the long run, it’s not the cheap factor. It becomes expensive.
The technique to remodeling or replacing a new rooftop is really to tear it off. That’s the bottom line to any roof job, otherwise you’re simply adding to the problem.
Fixing the problem is the most critical portion of any roofing contractor’s goal when tackling a project such as a roof job. Then when your roof installation will be fresh and new and most importantly, new! Finally, it will outlast any roof job that is layered, guaranteed!
Source: Roofing Contractor Michigan