Replies

1. 
   JTC1 | Sep 04, 2007 10:17pm | #1

   >> Question is how far below the drip edge should the gutter be given 1 inch per 40 foot general guidance?<<

   Not sure exactly what is meant by "1 inch per 40 foot".  I do not think you will like the performance of a gutter set to fall 1" per 40'. This would be 1/40" per foot.

   Slower draining gutters not only drain slower but also tend to accumulate more debris than faster draining installations.

   In your case you have a 30' gutter run (disregard the "L").  I like to slope gutters at 1/8" per foot.  Some will say 1/4" per foot. Others will say 1/16" per foot

   I would start the end farthest from the downspout with the top edge of the gutter in contact with the drip edge, 1-1/4" below at the L (10/8"), finish at 3-3/4" below at the downspout (30/8").

   The real question becomes, is your fascia wide enough to handle this drop? Generally gets to looking a little silly when the bottom of the gutter is below the bottom edge of the fascia - becomes a judgement call. Just keep in mind the more slope - the faster it will drain.

   If fascia width becomes an issue, I would lessen the slope in the 10' run to the L, then increase the slope in the run from the L to the downspout - this way the slope increases as volume of water in the gutter increases.

   Others will chime in soon.

   Jim

   Never underestimate the value of a sharp pencil or good light.

    

1. 
   DanH | Sep 04, 2007 10:26pm | #2

   Bing bong.
   So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin

2. 
   maverick | Sep 05, 2007 12:34am | #3

   I gotta think 1/8" per foot is a little extreme. at that pitch you're dropping 5 inches on a forty foot run. thats gotta be a little unsightly

1. 
   JTC1 | Sep 05, 2007 12:59am | #6

   >>>...you're dropping 5 inches on a forty foot run.....<<<

   yeah, or 3-3/4" total in a 30' run which is broken into a 10' run and a 20' run. 10' run drops 1-1/4", 20' run drops 2-1/2".

    

   Perhaps you subscribe to this one? - >>Others will say 1/16" per foot<<

    

   The OP mentioned 1" in 40', and I questioned the wisdom of that installation.

   I can't hang a gutter straight enough to maintain a slope of 1/40" per foot without puddles in the gutter which only go away via evaporation.

   As I said, "others will chime in".

   Jim

   Never underestimate the value of a sharp pencil or good light.  

    

    

1. 
   Sphere | Sep 05, 2007 02:23am | #7

   You are close. We would leave a level section then slope then level and then slope..1/8 per ft is OK, but if ya start running out of fascia, that kinda sucks.Spheramid Enterprises Architectural Woodworks

   "If you want something you've never had, do something you've never done"

1. 
   MikeSmith | Sep 05, 2007 02:38am | #8

   that's a difficult one... assuming you can't add another downspout.. here's how we'd hang that one

   at the high end .. jam  the gutter as high as you can under the drip edge.. use a good fascia hanger... and maybe SS screws  ( 1 1/4" x #10 are common )

   take a pail of water up and pour some in.... just drop the gutter enough so the water flows.. then pin the gutter... keep moving down.. most of the fascia hangers have holes for 2 screws.. but just use one until you like the overall flow.. then you can double screw them

   we also set gutters with a laser in the bottom of the gutter.. but nothing is as foolproof as the small pail of waterMike Smith Rhode Island : Design / Build / Repair / Restore

2. 
   DanH | Sep 05, 2007 04:21am | #9

   Another ding: The corner will be a PITA if there isn't enough slope (and possibly even if there is). Always a source of clogs.
   So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin

2. 
   DanH | Sep 05, 2007 12:43am | #4

   Could you show us your arithmetic?

   So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
1. 
   jhausch | Sep 05, 2007 12:50am | #5

   OP - "given 1 inch per 40 foot general guidance"

   Oops - My brain read this as 1/40th of a foot.

   like I said, it was my understanding there would be no math.

    

   I'll go back and delete.