On Oct 10, 10:43 am, MNRebecca wrote:
Well, I checked for blockages last night. None. I confess I'm a
little bummed. My house isn't that big... 1,800 sq. feet. Is it
logical that even a smaller home can have 'too much roof for the
gutters' in heavy downpours? By the way, Dave, the roof is shingled
with shangle shingles. The part where I'm presumably getting more
water than standard downspouts can handle is an area with a cathedral
ceiling over 2 inside vaults (one over a dining room and one over a
living room whose vault is perpendicular to the adjoining dining room
vault).

If you're sure there's no blockage anywhere in the downspout (or where
it enters the ground, if it drains underground), that simplifies
things. You need a larger downspout and possible a larger gutter as
well. You can have a handyman cut a larger hole where the existing
spout is now and fit a 3x4 downspout to replace the existing 2x3.
It's kind of hard to believe that the original installer would think
that a single 2x3 spout could handle 40' of roof. Typically there are
two 2x3s on a 30' run, so you're close to a 2/3s undersized downspout
arrangement.

Is there any water cascading over the front edge of the gutter
anywhere along its length?

R