Preventing Clogs in Underground Drain Pipes
This past week, we looked at issues caused by and related to cleaning (or technically, the lack of cleaning) leaves from gutters. We looked at how leaves can decompose And break down as they work their way from a gutter all the way down into the underground drains, if not simply cleaned from the roof and gutter in a proactive fashion.
Cleaning out underground drains though is much more difficult. In many cases, as well, the underground drains are also shared, in DC, between sewer and roof run-off. DC is a bit unique, because our historic city was built so many centuries ago, lot of the parts of our drainage systems are remnants of earlier times of historic building and engineering technology. The same scenario holds true for many parts of our underground urban infrastructure.
This matters to us, as roofing contractors, because we try to help our clients and even though this is outside of the scope of most roofer’s work inclusions, when the underground drains become clogged, it’s very difficult to remove the sludge and debris caused by leaves in the gutters and downspouts.
The types of leaks caused by clogged gutters and downspouts will often look a lot like a roof leak. The water will generally enter the rear of the building, but at the top of the wall, not through the roof itself. From that point, the water will drip down at the rear of the building, and make itself evident somewhere on the inside of the wall by damaging plaster and or drywall.
Where original historic building walls have been furred out so that the interior side of those walls are set inside of the original brick walls, the cavity created by that framing may allow the water to run downwards before it hits a horizontal ledge such as the sill or sole plate or the floor area where the leak will puddle and generally make itself evident by showing signs of leakage.
This isn’t exactly where the problems actually start, but it is where they’re often identified. These problems are often identified here at the floor areas or areas where there’s a horizontal ledge on the interior of the framing, because the water will pour out into the room where it puddles and builds up at a ledge. While it’s problematic, on one hand, it’s also beneficial on the other hand.
The picture below shows a typical Washington DC low-slope roof gutter in late October of 2024. This type of leaf build-up is typical, even early in the season when all the leaves have not all fallen off the trees yet.
It’s helpful to at least know that the leak is happening. When water runs unabated on the interior cavity of a wall, where we cannot see it and where it does not become evident, it still incurs damage. As the materials in the inside of that cavity are hydrated, again and again, with successive rainfalls, and meanwhile we’re not aware of the damage occurring if it cannot be seen or if it does not leak through or permeate from the inside of that cavity to the outside of that cavity, it causes much greater damage. This damage takes shape or form in rot and deterioration of the surrounding building materials.
When building materials are let to rot and fester in an area that is hidden from view, the damage is most often much more extensive before the problem is recognized and treated properly.
The picture below shows a typical Washington DC low-slope where numerous leaves have fallen and landed upon the rooftop. When the first rains come next, these leaves will wash down into the gutter.
The next picture shows a similar but different rooftop with the same conditions.
The next set of pictures below shows an alternative type of scenario where the roof is actually clean, by just coincidence, but the gutter has a leaf guard. Leaf guards are not a perfect solution because they also can clog which can cause leaks at the rear fascia of the building, the same way the problem would happen if there were no leaf guard at all. Both conditions, with Leaf guards or without leaf guards require upkeep and maintenance. As we mentioned in last week’s blog article, for this reason, we recommend that our clients have our company or others come out at least in the spring and fall season to check and clean out the gutters.
Here on our website, in other blog articles, we show several different examples of gutters with leaf guards. There are several different styles and types of leaf guards which have different characteristics and different pros and cons. This particular type of leaf guard is like a microfilter screen. It can work well to keep out most objects from the gutter, but also clogs easily and as we mentioned above and therefore also requires maintenance and cleaning.
The next picture below shows a handful of leaves into an otherwise open and clean gutter at the rear of a standing seam metal roof here in Washington DC. This particular roof doesn’t even have any trees nearby or above, yet still even in cases without trees towering over a roof, in the fall through spring seasons, leaves can often blow in with the wind from a great distance.
We recommend every building owner in DC who values the longevity of their roof (and their investments) and building use a contractor who values the simple and important principles of proper roof construction like Dupont Roofing DC. Learn more about our company and the proper techniques of working with roofing on historic buildings in Washington DC here on our blog at DupontRoofingDC.com, and you can call us at (202) 840-8698 and email us at dupontroofingdc@gmail.com. We are happy to help and at least talk through options.
