When Downspouts become Blocked

Fall is here and the leaves are changing colour. Sooner or later they will land on the roof and in the gutters. A clogged gutter system as the result of a bird’s nest, wet leaves, or clumps of dirt can inflict a lot of damage to a home’s exterior. When downspouts become blocked, runoff can backup into the eaves or overflow the gutters and then down the siding.

Water doesn’t drain properly.

A fully operational gutter system takes runoff from the roof, guides it through the gutter trough, and deposits it safely away from the house’s foundation via the downspouts. Blocked downpipes prevents the water from exiting the system. If you suspect that water doesn’t drain properly from the gutter system, check the downpipes during a steady rainfall or insert a garden hose into the gutter outlet near the top of the downspout. The biggest telltale sign that there are clogs somewhere in the pipe is no water flowing from out of the spout or there is just the thinnest of trickles.

Clogs cause overflowing gutters.

Clogged downspouts can also cause the gutters to overflow. Water inside the downpipes backs up into the gutter channel, resulting in water pooling under the eaves or runoff that runs down siding and collects near the foundation. Saturated soil or increased soil moisture levels leads to foundation problems related to compromised structural integrity such as shifting, sinking, cracking, and pitting. Oversaturated soil can also cause basement flooding.

 Water escapes from the seams.

When clogs in downspouts form near seams, they restrict water flow, causing water to build up, putting pressure on the places where two sections of pipe or an elbow and a section of pipe are joined together. If the sealant weakens or wears out, seams are damaged and start to leak.

Downspouts are too small.

A residential 5-inch gutter system is usually matched with 2 x 3 inch downspouts. Downspouts that frequently become clogged even when the gutters are cleaned regularly could be too small to handle the current volume of water and the amount of debris flowing through the system. Downspout replacement or upgrading to a larger downspout size will help stop repeated clogging.

Gutter sections start to sag.

Sagging gutter sections could be a sign that there is standing water in the gutter troughs. Downspouts that aren’t draining properly or are backing up due to blockages add additional weight to the gutter system. When parts of the gutters pull away from the fascia (your roof), inspect the downspouts for damage and/blockages.

Find the source of the blockage.

To prevent water damage as a result of clogged downspouts, you will have to find the source of the blockage.

At the top: You will need a ladder. Start with a visual inspection of the gutter outlet – the part of the gutter system that connects the downspouts to the gutter trough. If there is no debris or buildup impeding the runoff from flowing into the downpipes, the blockage is somewhere in the middle or bottom the pipe.

In the middle: To find a clog inside a downspout that isn’t readily visible, tap gently on the outside of the downpipe. If you hear a “clunk” instead of “ringing” there is a blockage that needs to be removed with a plumber’s auger.

At the bottom: Look into the opening of the bottom elbow to check for an obvious clog that’s preventing proper drainage and remove it.