Making Repairs To A Built-Up Roof

A built-up roof, or BUR, is made from alternating layers of asphalt and tar paper. When workers place one layer of paper on top of what is already there, they place the seams of the top layer in the middle of the tar paper from the row below. This way, if there is a leak at the seam in the top layer it won't be able to leak through the layer below—at least not right away. While a three- or five-layer BUR should be fairly durable, leaks can happen, and when they do, you need to know how to make repairs. 

What Leaks Look Like

The first step in making repairs to a BUR is inspecting your roof frequently so that you can find leaks before they become a big problem. You should look for cracks along the edges of your roof or against any objects that protrude from your roof. As the sun beats down on your roof, it will dry up the asphalt tar, leaving your roof brittle and prone to cracking, so you might also find cracks in the main body of your roof. Finally, you should look for blisters where water leaking through one layer pools up on the layer below. 

Making Repairs

Use these steps to make repairs:

1. Pull back the gravel that coats your roof. 

2. If you have a blister, cut out the blister and allow any water trapped between layers to evaporate. 

3. Cut two patches. The first should be one inch wider on all sides than the blister or crack you are trying to repairs. The second patch should be one inch bigger on all sides than the first. 

4. Paint a layer of tar onto your roof. 

5. Push the smaller patch into the tar until it becomes saturated with tar. 

6. Paint a second layer of tar onto your roof. 

7. Push the larger patch into the tar until it becomes saturated. 

8. Paint down a third layer of tar. 

9. Push the gravel back in place. 

Making repairs to an asphalt tar roof is not complicated. However, sometimes water can run between layers of your roof until it finds an access point into your roof. Thus, locating roof damage can sometimes be complicated. If you have already made your own attempt to repair a leak, or if you simply want to make sure that it is done right the first time, you should call in commercial roofing professionals to make sure that you get a quality, long-term patch.