How To – Extending Gutter Downspouts Around Doorways

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    In this HowTo we will extend a downspout from our roof gutter under a concrete pad that is near the front doorway of our home.

    Managing rain runoff from your gutter system is important for many reasons. In the summer months when rainfall can be heavy you need to have the water diverted away from your pathways and entrences to your home for comfort and safety. In the winter months when water can melt from snow on your roof you need to make sure that water will not refreeze in areas where it could cause slippery pathways.

    In addition to water problems from runoff at the surface level you need to make sure that water does not pool or enter the area around your foundation. This can cause water penetration into your basement or crawl space.

    Water runoff  from storms can actually flood your basement because the average home in a 1 to 2 inch rain storm may gather 10,000 or more gallons of water.

    In our situation we have a concrete slab that will be the pathway from our driveway to our front door. If you look closely the downspout from a section of the garage roof exits in a corner area which will flood if there is a large rainfall.

    To fix this problem before we plant the lawn and install the driveway we can install an under ground downspout extension pipe. If you have this problem at your home and your law has already been planted then you will need to dig up a portion of your grass to install the pipe.

    Cutting into sod should be done with a flat nosed shovel. This will give you straight cuts. To prepair for sod removal you should cut your lawn in this area as short as  you can. You need to dig the nose of the shovel into the ground about 3 inches below the surface then bring the shovel down somewhat parallel with the ground and dig across and under the turf. This will give you a section of grass that you can replant after you are done. Saving the grass that is in place is always preferred to replanting because you will see changes in grass color and texture if you just reseed.

    Now that you are ready you can dig a 10 foot long path to bury your perforated pipe in.

    We have already installed the 4 inch Solid PVC Pipe under the walkway slab.

    To do so before we poured the slab we nailed a few 2x4s together and buried them under the walkway location. You could just install the PVC Pipe if you want  but if you have a walkway that was already installed you will need to dig under the slab. Post Hole diggers or special shovels with a long 4 inch nose can be used to dig under small walkways pretty easily.

    Once the Solid PVC Pipe is installed you will want to backfill that hole the best you can to reduce erosion. This is why we use a Solid Pipe under the slab. If we used a perforated Pipe under the slab water would drain under it and cause failure.

    We can now attach our Elbow on the house side of the PVC Pipe with PVC glue.

    As you will see we also have a small grate cap that will sit loosely in the PVC pipe. You don’t want to glue it on in-case you need to remove it later for clean-out.

    Now that we have established a good angle for the pipe and installed the elbow we will duct tape the grate cap to the pipe and fill the surrounding area with gravel and then about 2 inches of concrete.

    It is important to create a basin with your concrete in this area so that water will head towards the drain opening. Remember to leave the cap on the pipe and duct tape it so it won’t covered with cement.

    After the concrete has had about 4 hours to cure you can pull out the drain cap and then use a large amount of silicon or siliconized exterior grade caulk to seal the area around the drain.

    During this time you can attach your black perforated pipe in the lawn area and backfill and replace your sod.

    To finish up your project you can fill the drain area with some large decorative river stone and maybe put a planter in that area. Adding soil right into the drain area and growing grass or flowers is probably not a great idea because it will clog your drain.

    This project should take you about half a day depending on the digging time.

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