Should You Replace Your Old Roof Before Putting A New One Down?

Long Island Roofing

Should You Replace Your Old Roof Before Putting A New One Down?

People everywhere love to look for ways to save money.  That's true from San Francisco to Long Island.  Roofing contractors will, for the most part, do the job how you tell them to.  Honestly though, in most cases, you're setting yourself up for problems down the line if you don't pull the old roof off first.

The big advantage to just putting the new roof down over the top of the existing is, of course cost.  It's faster and cheaper (by a thousand dollars or more) if you don't have to contend with the mess and headache of ripping the old off and hauling it away, but if it shortens the useful life of the new roof you're putting on, then in the long run, you're actually going to wind up being worse off because you tried to take a shortcut.  In general, you're looking at shortening the new roof's lifespan by up to 20% or so if you don't remove the old first.

You can still do it, obviously, and many contractors will do it that way if you insist, but if one or more of the following conditions apply, you'll really only be hurting yourself:

• If you live in an area where ice dams are possible and your roof has no protective membrane to ward off ice and water (This is true of any area where the average temperature in January is below freezing, so this is certainly true in Long Island.  Roofing contractors who insist on pulling your old roof off before replacing in those northern regions will be doing you a big favor in the long run!).
• If your roof already has more than one layer, take it all down!  Layers built on top of layers is only asking for trouble!
• If an inspection reveals that the existing roof is in bad shape with missing, curled, cracked, or otherwise damaged shingles, it should probably come off (and if it's not in that kind of shape, you probably wouldn't be considering replacement!).
• If the decking is rotting or deteriorating, the old needs to come down.  This is because you won't be able to make the necessary repairs otherwise, and it won't do you any good to install a new roof over rotting materials!
• If your new roof is made of a material lighter than the original roof, the old roof needs to come down.  This is to say, if you're installing lightweight shingles over heavy duty ones, then all the bumps and ridges from the old stuff is going to show through.

What it really boils down to is expediency over quality.  If your roof is in dire need of repair and you have no other option but to do it as cheaply as you can get by with, then yes, installing right over the top of the old roof is probably the way to go.  You'll save time.  You'll save money.  

Consider the problems that might surface later!  For instance, let's say, in a couple years, a leak develops.  Do you have any idea how hard it will be to trace the leak to its source through multiple layers of roofing material?  That's going to make finding and actually fixing the problem virtually impossible, and given the shortened useful life of the new roof, unless you sell and move (foisting the problem onto someone else down the road), you'll be faced with higher costs when it comes time to re-replace the roof, because now you've got two layers of material to strip off and dispose of, to say nothing of any repairs the decking might need.