Clogged Downspouts and downspout Drainage

Clogged Downspouts

Clogged downspout filled with tree seeds and leaves
A clogged downspout can also cause water to run back under your roof line, causing water damage to the plywood under you roof and the soffit that holds the gutters by the roofline. Fixing either of these parts of the house can be a very costly repair which could have been avoided with routine downspout clean outs. This can be the hardest part of gutter cleaning since material jammed down in the downspouts is hard to bring back up, so it either has to be broken up or the leaders and joints in the down spout system taken apart. This just takes more time to do but prevents making it worse.
Places Downspouts Clog
At the very top of the downspouts where the gutter and downspouts join is where the most clogs occur. Leaves, seeds, tree flowers and Debris tend to float to the opening of the downspouts. With relatively low flow these materials can hang there and then the gutter dries out and gets stuck or almost glued there. Then the next rain comes along and hangs up on the dam that was created by the first piece hung up at the down spout. As this happens a number of times the downspout opening gets bridged over and literally plugged up. Then the entire gutter system stops working and overflows damaging the house, landscaping, and foundation. What is often remarkable is when the blockage is removed from the top of the downspouts the rest of the system can be perfectly clear.
Clogs at the bends in the downspouts are the second most frequent area of blockage. With perfectly straight runs from the gutters down to the ground there is nothing for material to hang up on and they seldom get clogged. With Bends to fit the profile of a house the potential for twigs, screws, or debris to start a back up greatly increases. The farther down the system the harder it can be to clean out.
Clearing Clogged Downspouts
Pressurized water from a hose pushed down the system can flush the blockage out. Be careful not to put a hose down with a nozzle on it since it can get stuck so that it can not be pulled back out.
Plumbers snakes have a auger tip that can cut through a blockage and pull lose some debris to start the clearing of the Downspouts. The disadvantage to this is your can also dig through a joint in the gutter system if you are not careful. If the material can be loosened up then running it up and down the system can clear it so the water will flow freely. An electricians snake works at the first elbow when the gutter curves under the fascia to push and or probe for any blockages, but not well for problems lower down in the system since all you do it jamb material down further into the downspouts.
Downspouts that go into underground drainage can be hard to make sure they are clear. If there is a clean out access point at the ground or a way to take out the downspout then a snake or hose can be inserted to check if it is clear. Often to really be sure a large amount of water is needed to see if the downspout drainage is working well.
Downspout Drainage
Keeping the water flowing from the roof and gutter system is what the downspouts or leaders do as part of the gutter system. If they do not drain well you can wind up with over flowing gutters from clogs at the top or too much flow at ground level not handled well. Drainage systems parts often are a second thought when the house is first built. Over time it becomes clear with observation if there are problems with down spout drainage. Solutions can be as simple as cleaning of the system at the top and all bends, or adding to the system.
Soil Type
Rainwater that drains onto soil near your home from the downspouts is generally not a problem if you have sandy or very well drained soil. Here splash blocks may be all that is needed. However, poorly drained soil, pavement and patio’s that prevent good dispersal of rain water. With non porous surfaces or clay soils that don’t drain that well basements and crawlspaces can become indoor swimming pools in periods of heavy rainfall or sustained wet spells.
Downspouts drain water to the area of the foundation and if there is no slope away from the foundation it can remain there and soak the soil along the foundation wall. With good sloping away from the downspouts the water will be harmless. Overtime many changes occur that change the slope such as settling or landscaping that changes the slope resulting a storm or winter thaws bringing a wet basement. Older homes that have never had a problem all of a sudden are wet. I find this situation especially prevalent in older neighbor hoods with relatively flat lots.
Drain tiles can stop soil erosion under downspouts. Many people do not realize just how much rain falls from the sky in a moderate rainfall. For sake of discussion, let’s consider a normal ranch house that has an attached two car garage. If the structure measures 30 feet by 66 feet and has a 2 foot roof overhang, there is 2,380 square feet of roof ready and waiting to catch rain drops. A moderate 1 inch rainfall will generate 1,483 gallons of water on this roof. This water will hit your splash blocks and enter the soil about 30 inches away from your foundation. If your region receives 40 inches of rainfall a year, you will inject about 59,320 gallons of water into your wife’s gardens. That might be a little overkill, don’t you think? If your foundation is currently leak proof, your sump probably accepts a good portion of this water. If the sump pump discharge pipe merely dumps the water along side your house, you end up recirculating this same water time and time again. This wastes electricity and leads to premature pump failure. I feel that your storm water and sump water should be piped away from your house. Some urban areas allow this water to be connected to public storm sewers and water retention basins. If this is not available, pipe the water to the lowest portion of your lot where it would have drained naturally before your house was built.

Clogged gutters and leaders
The cumulative numbers are high and normally the water is dispersed away from the house. The soil absorbs and disperses water up to a certain amount then it can only hold so much. When this happens and the water is up against the foundation it may well find it’s way into the basement or crawl space on the other side. Damage from over flowing gutters can be rotting siding and your home building components. Landscaping erosion from water spilling over uncontrollably can be with both force and volume.
Check for Problems
Look for problem areas and signs of clogged gutters and leaders. Things to look for are mulch being washed away under the gutter system. Stains on the side of the house from water flow. Lateral areas were plants do not grow in from the water damage. Lots of times water will create a small valley from the erosion.
Down spouts that are clogged often will show discoloration or black sections were water repeatedly leakes out. During a rain water may not come out of the downspouts at all or take a long time for a very slow flow of water to developemeaning it is blocked in the system.
Downspouts should have extensions if needed to direct the rain water away from the foundation and the side of the house. If the area around the house slopes away well then only a splash block may be needed.


We use high pressure jetting equipment to clean out downspouts and drainage piping.  We also replace pipes under the ground when cleaning is not possible.  We use the latest in camera technology to locate problems and provide a permanent solution to your rainy day problems.