The most recent article on our website looked at fascias and rake boards at the start of a two-part series on the topic. Today we will continue looking at these elements where they create the termination or outside edge of a roof membrane, mainly a transition between the top of an exterior wall and the roof system.
In the picture below, you can view down between two different buildings in a rear elll area. On the left side, it is the side termination of a roof system which feeds into a gutter. The gutter is a five inch aluminum gutter which channels or funnels water away from the rooftop system over to a downspout at the rear side of the roof. On the right side of the picture, the neighbor’s roof has a gravel stop at the higher side. Traditional freestanding homes with gable roofs will often have a ridge in the middle. In this case, the gravel stop works a little bit like a ridge, except the gravel stop does not set a demarcation between rooftops with different slopes on a row home configuration like this.
In the picture below you can see that the wall below this side of the roof, on the right hand side of the picture, has vines growing up to the roof edge and up under and around the fascia board. Those plant roots and tentacles, from a Virginia creeper vine, in this example, are causing damage because as they grow they go deeper into the crevices between the roof system and the building framing and as they grow thicker and wider, they spread those materials out causing gapping and separation which can allow weather and rodents to enter into the building. It’s very important for a building to be able to maintain an exterior envelope. An exterior envelope doesn’t have to be watertight without permeation at all locations, but as the space between the termination of the roof widens, it can allow these elements to come inward in through the building envelope and cause serious problems.
In contrast to the building shown in the picture above, the next building shown in the picture below, is not clad with an aluminum siding. The rear facade of the building is the original historic brick masonry. and the projecting part of the building is an actual open rear deck / balcony. The area where the fascia board would typically be installed is covered with an original rusting ferrous metal which was installed on top of the original rooftop framing rafter. A portion of the old rotted wood is exposed below that ferrous metal. That lower area of the rafter wood was once covered with a historic 15 lb asphalt impregnated felt paper. Now, at this point today though, that paper has long deteriorated and blown away in the wind. In the many years since that time that portion of the deck roof framing has slowly rotted and withered away, today it looks like a wind-torn piece of driftwood. At the top of that old ferrous metal flashing, you can see the gravel stop, which allows the modified bitumen membrane to terminate, run past the edge of that old framing. In modern construction, in the case where this was an actual building wall, a rake board would be installed at that location.
The next picture below shows the same building, at the same rear area of the building but also shows a portion of the larger building covered with the same modified bitumen rooftop membrane, but with a closer to complete system of elements. At the rear wall of that main building, a fascia board would normally be installed to terminate the modified bitumen membrane or allow that portion of the modified bitumen roof membrane to transition and feed into a gutter.
Here though, there is an anomalous detail which is different to other typical or more common row home roofs. Because the rear portion of this roof runs from side to side, the rear edge of the roof does not require a gutter. Also, since the porch roof connects to the main part of the original building at a location lower than the level of the main roof, a transition of modified bitumen has been overlaid on top of that area of the rear porch’s modified bitumen rooftop membrane.
The next picture below shows an example of a rake board with a gravel stop aluminum gravel stop termination on top of the rake board area. The rake board is not actually in place and instead the previous contractor took a shortcut and installed the siding all the way up to the top of the wall. In this case though that will actually work okay, the only problem is that this is also a location where rodents can work their little bodies into crevices between loose building materials.
Often, our company is hired to check the condition of roofing and rooftop elements, in some cases after new clients have recently purchased an old property and began living there for the first time. In many cases though, generations of prior owners have lived in these buildings and been tight on cash and hired very poor quality contractors. Looking at the picture below you can see some of the work done by low quality contractors dripping fiber modified aluminum paint down the side of the building, for example.
Smart and proactive replacement, construction, upkeep and maintenance of low slope roof and mansard roof systems requires an enthusiastic interest and understanding of historical methodologies, waterproofing principles, and building science. Here in Washington DC, historic and modern residential and commercial buildings are extremely expensive and the roof and related systems provide the shield that preserves the building.
We encourage all of our clients, and all readers of this article and to our blog in general, to prioritize the value of quality construction and building maintenance, and develop a relationship with our company. You can learn a lot more on our blog. Feel free to check it out. If you have questions about the roof and related systems of your building in Washington DC, contact us or fill out the webform below and drop us a line. We will be in touch if we can help.
