On Fri, 4 Mar 2005 08:13:06 -0600, manhattan42
scribbled this
interesting note:


Covering over a roof is still accepted by building codes as a viable and
useful option and shingle manufacturer's accept the process as well.

If an interior and exterior inspection of the roof sheathing yields no
problems, there is little reason to rip off and replace the existing
layer.

Replacing your automobile tires if you get a flat is also an option if
you can afford it.

So far as I know, National Building Codes allow up to three roofs on a
house. Just because it is up to code does not mean it is ideal. A
house with more than one roof installed is more likely to develop
leaks (because the roof exposed to the weather is not installed over a
uniformly smooth substrate) and I've never seen a second roof like
this last as long as it should. In every case I've seen, a house with
a second, third (or more) roofs installed require attention far sooner
than they would if there had been only one roof.

The only reason to roof over an existing roof is because of money. It
takes more time and labor and dump fees to remove an existing roof.
Sure, it is up to code. Sure it is common practice. Yeah, it is
cheaper. Is it best practice? Nope.


--
John Willis
(Remove the Primes before e-mailing me)