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Where to route gutter?

The back of my garage roof does not have a gutter and rain, snow, etc. ponds on the paver walkway below AND when cold enough...freezes. I want to install a gutter but I have no where to route the downspout. No matter where I bring it down, it will be on a surface that is walked on and could freeze. I'm thinking about routing it underground. Has anybody done this? If I dig a hole and fill it with stone, etc., should this work to remove the water? Let it perc into the ground? Thanks in advance.

Re: Where to route gutter?

Ideally you want the water going to the street, which is lower than the house. But if the house is below street grade, this can work, depending on your soil type. Why don't you run a simple test: flood the area and see how fast (or slow) the water disappears.

I once poured a concrete driveway which was lower than the street. To channel the rainwater away from the house I dog a 3'x3'x4' deep hole in the lowest spot, filled it with crushed rock and set a drain crate on top, flush to the finished concrete.

Re: Where to route gutter?

I have a really good (old) post hole digger that was given to me by my dad. I'm thinkin that I will simply dig a post hole (core) about 4' deep or so. I've dug holes this deep for fence posts in my yard and hit sand. I'll then fill the hole in with stone (to stabilize it) and have the downspout terminate in the first foot or so. I think I'll do the test like you mentioned though and fill the hole with water first to get an idea of how fast it percs.

Re: Where to route gutter?


The post hole digger idea will almost certainly fail---the amount of runoff you're getting from the garage roof will overwhelm such a small hole in no time, and the first freeze cycle will stop it cold!

You need something like dj suggests, where you would build a low-cost, simple dry well approx 10' from the garage foundation and connect it with 4" plastic drain pipe.

I've always found putting in a simple dry well VERY SATISFYING and REWARDING work---it's one of the few chances a DIYr has to spend the least amount of $$$, a minimum amount of labor & and get a satisfying result.

Consult the Google site by Philip Schmidt below entitled "building a dry well"---once at the site, click onto the DRAIN PHOTO (Page 104) and scroll down to the section entitled "Building a Dry Well"-----click onto the left "magnifying glass" to enlarge the print & images-----the diagram of the simple system he has there is INVALUABLE---it shows all the low-cost components and how they're arranged with the least amount of manual labor.

The YOU TUBE videos are also great as a guide to this project----if the You Tube site won't load, Google the phrase "You Tube Video Installing a Dry Well".

For additional sites on this topic, Google "installing a dry well".

If the catch basin item is too expensive you can buy a 5 gal red plastic gasoline container at the discount stores for $10 and bury/feed the downspout directly into the buried gas can after cutting a hole for the downspout and a hole for the 4" drainpipe going to the dry well---the job of the catch basin is to catch & hold the roof runoff debris like shingle and leaf particles, etc. so they won't eventually clog up the 4" pipe & the dry well----a separate hole and drain cover with a short length of pipe can be installed in the gas can to provide a "cleanout"; the catch basin is cleaned out once a year by extending a gloved hand down into the catch basin to remove accumulated material, usually the only maintenance needed for this system.

All the parts for this project can be bought at the big box stores like HD/Lowe's---please note that drain materials for a dry well have a separate classification, having thin-walled piping not more than 1/8" in diameter---they are located in a separate part of the store, and NOT to be confused with the MUCH THICKER (and more expensive) Schedule 30 plastic drain pipe used for indoor code plumbing or sewer drains---make sure you're buying the thin-diameter plastic 4" pipe & fittings designed for outdoor drain & dry well work; the 4" drain pipe can include the black 4" corrugated sections or coils and fittings that are also used for this purpose, but I prefer the solid white 10' sections of 4" drain pipe.

The plastic trash barrel used as the dry well has to be drilled full of holes----the site recommends large rocks to fill it, but, in fact, anything you have hanging around the house, such as broken bricks, small rocks, broken pieces of concrete, etc., can be used to fill the barrel---but do not use any wood products.


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