Roofing over old roof

Posted by red on November 23, 2006, 1:35 pm

I am probably obsessing over this, but if I do decide to roof the
back-half of my existing roof, what criteria do I use to decide whether
I can roof over the existing shingles or not?

Posted by David Nebenzahl on November 23, 2006, 1:50 pm

red spake thus:

> I am probably obsessing over this, but if I do decide to roof the
> back-half of my existing roof, what criteria do I use to decide whether
> I can roof over the existing shingles or not?

1. How many layers of shingles are already there (there's a limit to
what any roof will support).

2. What condition the top layer of shingles are in.

3. Whether you want to do a half-assed job or not.

--
Just as McDonald's is where you go when you're hungry but don't really
care about the quality of your food, Wikipedia is where you go when
you're curious but don't really care about the quality of your knowledge.

- Matthew White's WikiWatch (http://users.erols.com/mwhite28/wikiwoo.htm)

Posted by red on November 23, 2006, 2:13 pm

David Nebenzahl wrote:

> red spake thus:

> 1. How many layers of shingles are already there (there's a limit to
> what any roof will support).
> 2. What condition the top layer of shingles are in.
> 3. Whether you want to do a half-assed job or not.

The original roof was put on in 1970. The south half was replaced by
the previous owner about 1993, being stripped down to bare deck. The
north half, being in decent shape, was left alone at that time.

Now the north half is on it's last legs. Obviously it needs to be
replaced, otherwise, I wouldn't attempt it. So, I would be putting
another layer over one existing layer.

I'm a 42-year-old woman who will be helped by her 18-year-old son ( I
hope). We did the shed roof last summer/fall with eight bundles and it
was pretty rough going, especially hauling the bundles up to the roof,
but I am highly encouraged by the fact that we have had two solid
months of rain and no leaks on the shed.

So, I'd like to avoid the extra work of tearing out the old shingles if
possible. On the shed, we just roofed over the existing roll roof with
three-tab shingles, and except for one row where my son forgot to
stagger the shingles, it looks great.

So, what specifically do I look for to decide if going over the top is
"doable."

Posted by on November 23, 2006, 7:17 pm

>I'm a 42-year-old woman who will be helped by her 18-year-old son ( I
>hope). We did the shed roof last summer/fall with eight bundles and it
>was pretty rough going, especially hauling the bundles up to the roof,
>but I am highly encouraged by the fact that we have had two solid
>months of rain and no leaks on the shed.

In many places, you can get rooftop delivery of shingles. Might be
worth checking.

Posted by Joseph Meehan on November 23, 2006, 2:22 pm

red wrote:

> I am probably obsessing over this, but if I do decide to roof the
> back-half of my existing roof, what criteria do I use to decide
> whether I can roof over the existing shingles or not?

Generally I would say you can roof over one layer of roofing if it is
flat and in generally good condition. If it is curling or starting to fall
apart I suggest taking it off.

Stripping it all also gives you a chance to evaluate the condition of
the deck as well.

--
Joseph Meehan

Dia 's Muire duit

Page 1 of 2 1 2 > last >>

Similar Threads	Posted
Roofing and roof jacks	April 25, 2007, 8:35 pm
Roll roofing, steep roof.	October 30, 2006, 2:55 pm
Re-Roofing a Tar & Gravel roof with Asphalt Shingles	November 2, 2005, 6:52 pm
Roofing question - How many downspouts do I need for a given area of roof?	November 6, 2005, 6:57 pm
Install "Rubber Roofing" on Flat Roof Garage	April 14, 2007, 9:38 am
Roofing - Wish to put 90lb rolled over existing torch-down roof.	May 16, 2008, 8:45 pm
Hy-Grade Hy Grade Steel Roofing Roof Company WARNING	June 12, 2006, 12:01 pm
Cost Estimate - Sunken rafters under the roof (showing dips in the roof)	November 30, 2006, 5:43 pm
New roof jacks in existing asphalt shingle roof	March 12, 2006, 12:10 pm
How does Roof Time LLC handle a roof project?! www.time2roof.com	November 27, 2007, 3:23 pm