The Pros & Cons of Waterproofing a Tar & Gravel Roof

Cost

• One of the primary advantages to waterproofing a tar and gravel roof is the fact that doing so can help cut down on other maintenance costs in the long run. A roof that is not properly maintained can spring leaks and cause significant damage to the home or building below. The cost of maintaining a tar and gravel roof is generally lower than the costs associated with many other types of roofing systems as well.

Drainage

• One of the disadvantages of waterproofing a tar and gravel roof is that doing so can lead to significant water buildup on a roof that is not properly drained. Of course, this is more a drainage issue, but the decreased capacity of the roof to hold water will make it necessary for water runoff to occur at a higher rate. Waterproofing sealant can create a layer that makes the space between the gravel impermeable. To prevent excess buildup, additional steps may need to be taken.

Materials

• One of the major cons of waterproofing a tar and gravel roof is that it tends to be an extremely messy job and may have to be performed under less than ideal conditions. Even on days when the temperature is modest, tar and gravel roofs put off considerably more heat than other types of roofs and can increase the temperature of the area in which the worker will be applying the waterproofing sealant. The messy tar coupled with intense heat can also create noxious odors.

Resistance

• Added resistance to rain and the elements is one major advantage to waterproofing a tar and gravel roof. These roofs already protect the home or building from the weather to some extent, but waterproofing creates an even greater barrier that prevents the effects of water erosion on the tar and gravel itself. This can help eliminate the need to replace the roof as often, which is the main way that these roofs are often maintained. Tar and gravel roofs can have anywhere from three to five layers, as it is common to simply place one layer over another for maintenance purposes. These roofs become heavy over time. If you simply waterproof the first layer, you may not need to add additional heavy layers over time.