Roofing Tar 101: Main Uses and What to Expect for a Quality Service

a man repairing a roof

Roofing tar has been the flat roof covering substance of choice for more than a century. The vast majority of commercial buildings and flat roof constructions in America have a roof tar substrate that holds out the wind and the rain. Roofing tar resists water effortlessly and will even “heal” from minor damage. However, it is extremely heavy, requires time and expertise to install, and cannot be removed without great effort. There are also environmental concerns. Still, those have been largely mitigated by research in recent years.

Uses of Roofing Tar

Roofing tar is a petroleum or coal based substance. It is heated and spread across a flat or slightly inclined roof. The tar sets and forms an impenetrable barrier between the rain and the tar paper roof or other surface below. Roofers will often cover it with a layer of gravel to disperse heat and protect the surface. Roof tar weighs an enormous amount, and the roof will carry a substantial burden when coded and prepared. Gravel is also not inconsequential in its weight.

A Short History of Roofing Tar

Roof tar was originally made from pine tar, a natural product of pine trees. It was difficult to obtain, difficult to work with and melted at much lower temperatures than what we are used to. In the 19th century, workers realized that coal tar was an effective substitute. They found out that once this material is mixed with asphalt it became the composition roofing substance of choice.

Ideal for flat roofs or roofs with gentle slopes, coal tar was the roofing standard for the world and remained so for years. Even today the petroleum products used to seal modern roofs are extremely similar two coal tar in both composition and application. However, modern materials have given amazing options to those who take the trouble to obtain the proper formulation for their purpose. For example, we now have cold tar. This is a polymer-modified petroleum tar that has been specially adulterated with specific chemicals to let it poured and spread at room temperature.

Roofing Tar Application

a damaged tar roof

The first thing needed for any roofing tar application or tar roof repair is the proper sort of day. You need a dry day with at least 40 degrees Fahrenheit. The ideal situation would be a day with a temperature of at least 70 degrees. This is necessary for the tar to set properly. Roofing tar must be carried onto the surface, a substantial task in and of itself. Cold tar is ready to spread immediately. However, hot tar roofing must be heated to approximately 125 degrees.

At that temperature the thick, solid substance becomes viscous and liquid. It can then be poured or spread easily, usually with tools quite similar to mops. After applying the roofing tar neatly and evenly to the designated surface the roofers will coat it with gravel. This loose stone will meld with the setting tar, intermingling with the top layers and granting protection from the sun’s rays. Moreover, it allows workers to walk on the roof without damaging the tar. This material forms an incredibly durable layer of weatherproofing.

After this the tar and gravel roof is allowed to set. This means that it cools to the proper temperature to form a solid and waterproof mass. The tar will not set properly when it is raining or wet outside, because the precipitation mixes with the tar unpredictably and cause blisters and breaks in the surface. These could someday form points of vulnerability from which the weather can begin to work its way inside.

Roofing Tar Maintenance and Patching

One of the vulnerabilities of roofing tar and tar paper installations is that water, once it has found a gateway into the surface, has a tendency to travel before it penetrates the ceiling below. This makes holes and leaks extremely difficult to find. They tend to develop around flashing, creases, and points where tar paper meets. However, once the leak has been traced back to the source, it is simplicity itself to repair. Simply remove the damaged tar, cut back the tar paper, and treat the exposed area like a new installation.

Roofing Tar Removal

workers removing roof material

Unfortunately, the advantages of tar become disadvantages when removing it. Taking off a tar roof takes an incredible amount of work. There is simply no way to do it other than intense manual labor of the most detail-oriented kind. It is messy and creates enormous amounts of waste. The average tar roof will create two full dumpsters worth of debris. This debris can often be recycled, so the harm to the environment is minimized, but there is no easy way around the labor required. No amount of chemicals or solvents will help. The roofing team simply must use hand tools to scrape every bit of tar off the surface. At the end you will be left with a sticky, dirty roof, but it will be flat, free of obstructions and ready for a new layer of tar to be applied.

What to Expect from a Quality Roofing Tar Service

Whether a service is taking an old roof off, putting a new one on or fixing an existing installation, there are certain things that all professionals have in common. They are clean, which means they will be organized and prepared. Dumpsters and garbage chutes are installed and tarps cover all vulnerable areas of the home and grounds. Professional roofers arrive to work on days with appropriate weather. This is considered because roofing tar simply does not behave properly when it is raining or even notably damp.

Their accouterments will be as clean and tidy as possible when dealing with such a sticky and messy substance as tar. Upon inspection of a completed surface the satisfied customer finds no blisters, bald spots or splits in the tar, gravel or paper. Water placed on the roof will absolutely not leak through. If the roofing team has removed an existing tar surface, then the work will be done neatly and completely. No puddles of tar or piles of debris will remain.

When it comes to inexpensive, durable impermeable surfaces for flat roofs, there is no way to beat roofing tar. It has been the standard for over a hundred years precisely because it works so well. Whether you want to build a new building, fix an existing roof or remove the tar from an aging installation, preparation and attention to detail are always rewarded. Roofing tar installation, maintenance and removal are specialized to tasks that will generally be carried out by professionals. However, this does not mean that you should not know anything about the subject. Informed consumers always get the best results for the lowest prices. By educating yourself about what to expect to cost you get the best roofing service possible.

Image sources: 12, 3