I am about to replace my gutters, one guide I have read say the gutter should never be more then 30mm below the bottom of the roof tiles, another says 50mm.

What is the reason for this?

What is a safe distance?

(I want to get a good fall on the gutters and I expect that the bottom of my tiles are not level… I am planning to fit felt support tray at a later date)

  • How far below the drip edge is the current gutter? Why can't you install the new gutter in the same place as the old one?
    – Tester101
    Jul 11, 2012 at 15:06
  • @Tester101, the current gutter does not slope towards the outlets, so it overflows etc.
    – Walker
    Jul 11, 2012 at 15:53

3 Answers 3


3-5 centimeters is in the 2-3 inch range.

Any more and you run the risk of water running off the tile and overshooting the gutter.

The gap can vary some because the gutters must slope towards the downspout.

Edit post comments: When you install your new gutters, put the point furthest from the downspout at the highest possible point against the bottom of the roof, and then slope gradually down to your downspout. You're never going to hit the "maximum" that way.

  • Thanks so the key is the distance between the front of my tiles and the far side of my gutter - easy to fix as I can push tiles back a bit if they overhead too match.
    – Walker
    Jul 11, 2012 at 13:14
  • 1
    You should not push the tiles back beyond manufacturer recommendations because you need to make sure you have a proper drip edge. If you don't have that, water will collect at the end of the tile, wrap around and soak into the underlying surfaces that aren't supposed to get wet. Jul 11, 2012 at 13:27
  • 3" seems like a lot. If you start at 3", you'll be at 3 3/4" at the end of a 30' run. Depending on the slope of the roof, the water might cascade right over the gutter (but I'm no physics major, so I'm not sure how to calculate the path of falling water).
    – Tester101
    Jul 11, 2012 at 15:04
  • @Tester101, You got it the wrong way round, 3" is the point away from the outlet, so it gets less closer to the outlet.
    – Walker
    Jul 11, 2012 at 15:55
  • 1
    @Walker Huh? your gutters slope up towards the downspout, not down? You must have some odd water where you are, if it flows up hill. The 3" would be the distance measured from the drip edge (the point at which the water falls from the roof), to the top of the gutter. Since the gutters have to slope down towards the downspout, this distance will increase as you get closer to the downspout.
    – Tester101
    Jul 11, 2012 at 16:01

Start at the highest point with the back of the gutter as high as it will go (up against the bottom of the slate or tile or galvanised iron roof). Slope the gutter down form there towards the spout. If the run is long, you may need flashing to cover the exposed part of the facia. Water will blow in there, and rot the timber facia. Flashing will start from underneath the roof and bend down and overlap the back of the gutter.

Don't assume that the gutter is already sloping to the spout. Check it, get the slope right before installing brackets etc. Use a transparent plastic hose filled with water to check levels.

P.S. Some modern guttering has the back lower at the back than the front. Don't use it. When the gutter overflows, where do you think that the water will flow? Back to the house, and depending on the design of the house, water will find its way inside the exterior wall. If it doesn't do that, it time it will rot the facia.

In some modern houses in Sydney, overflow water found its way inside the exterior wall, rotting the timbers supporting the interior wall, floor timbers, and carpets.


My understanding is that if the gutters are placed too high that a sheet of snow could slide off and if it catches the front of the gutter it can tear it off. I read that the start of a gutter needs to be low enough that if you took a level and laid it on the roof it should clear the front edge of the gutter. This way any snow sliding off would clear the gutter and not damage it. My understanding is then a 1/16" per inch pitch is standard..

Gutters that are too high can enable runoff water to drip down their back side, which in turn can cause deteriorating fascia boards and stains on siding. Hanging gutters too high is a common mistake..

  • 2
    Your post cuts off mid-sentence. Please edit it to add the rest.
    – Niall C.
    Oct 25, 2019 at 17:19
  • Hello, and welcome to Home Improvement. It would be good to finish your answer, or it may be deleted. And, you should probably take our tour so you'll know how best to contribute here. Oct 25, 2019 at 20:41
  • sorry I can't explain why that happened as I didn't intend for my comment to be cut off in mid sentence... Maybe I was confused and was thinking I was talking to my wife...lol... Oct 26, 2019 at 18:05

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