On Tuesday, March 13, 2018 at 8:07:14 AM UTC-4, Robert11 wrote:
Hello,

Getting ahead of myself here, but let me ask while I think of it:

Live outside of Boston.

Will probably go for a new roof in the Spring.

How "necessary" or desirable is it to remove the old
shingles first ?

Seems like it would be a much bigger job if we have the Contractor
remove the old (25 years old, but still fairly good; no curling, etc.)
ones first.

What are the pros and cons, please ?

The biggest plus is that it allows full inspection of the sheathing to
make sure it's not rotted, deteriorated, that it's in good shape and
not in need of replacement. Personally, on just about any roof, I'd
pay the extra cost for removal. The older the house, if there have
been any leaks, any issues, then the more important it becomes.




What else should I be asking the Contractor ?

After you find the shingle you want, ask the contractor to give you
some houses near you where they have put them on. Then you can see
what they look like on a house and also if the homeowner is around,
you can ask them how the contractor did.





e.g., what "grade" of Shingles for up here in New England ?
I imagine most of the cost is the labor; right ?

It's probably about half labor, half materials. I'd go with one of
the architectural grade shingles or better from any of the major
shingle manufacturer's, depending on what looks good to you.




That Rubberized sheet I think the use as a matter of course:
How far back up the rood should it extend ? Further is better ?


By code across most of the colder parts of the country, it goes from
the edge of the lower roof until it's 24" past where it meets the
heated part of the structure. It's for ice damming and that's the
critical area. It's also used in valleys and similar areas, if the
roof has them.




etc., etc. ?

Thanks, appreciate your opinions,
Bob

Is the roof adequately ventilated? This is the time to make sure it is.
Today most pros believe a continuous ridge vent together with soffit
vents are the best method. If you have a ridge vent, you can also
decide what kind of ridge vent you want use. They range from cheap
roll on filter like material, to actual rigid ones. I'd go for the
latter because I believe they have more open area to let air flow.
If you need any other venting fixed, eg thinking about putting in
a bath fan, have a bath fan that is vented to the attic instead of
outside, have box vents and want to move to ridge venting, are using
power fans and it needs to be replaced, etc, now is the time.