Understanding Gravel Roof Restoration

By Cayden Wemple.  

Sometimes it can be hard for building owners to know if their roof has gravel on it, let alone if it can be restored, but Greg Hlavaty has the answers. 

There is so much that goes into the performance of a roof, and there are many important details that make up a roofing system. In the case of roofs that have gravel on them, it's important to understand what the purpose of the gravel is. On a new episode of the Understanding Roof Restoration podcast, host Karen Edwards sat down with Greg Hlavaty of Western Colloid to discuss the matter. 

Many people think that restoring a gravel roof can’t be restored, but it certainly is possible. The first step is understanding why the gravel is there in the first place.  

“Gravel does three things,” Greg says. “It adds a little bit of weight to the roof for wind resistance and what have you. Then it adds UV resistance, because no sun's going to get through that. It doesn't keep the temperature cool if it's a hot day, but it doesn't let the UV in. If you keep a good heavy layer of gravel on there, no UV is going to get through and degrade that asphalt. Next it is fire resisting. If you put enough gravel on a roof you can get a fire rating with paper towels. It is a barrier to the heat.” 

When the gravel roof is nearing the end of its lifecycle, the gravel needs to be taken off. This has proven to be an obstacle for contractors. “The first thing they'll do though on a gravel roof, is they'll sweep it and vacuum it. We always recommend a vac, sweep, vac. Where they vacuum it, sweep it with either a power broom or a very stiff bruise, then come back and back it again,” says Greg. “There's a layer of gravel that is uniformly embedded into that asphalt. That doesn't come off very easy.” 

For four decades, Western Colloid has been able to restore gravel roofs because of their asphalt emulsion. “An asphalt emulsion is an asphalt that isn't readily flammable. It is relatively inexpensive, so you can use in the higher quantities,” Greg shares. “Asphalt emulsion is a combination of a straight run distilled asphalt, one that's not been oxidized like hot mopping asphalt … It is mechanically ground with a bentonite clay, which hence colloided. It becomes a colloid product and once the water evaporates, it's a combination of bentonite clay and asphalt.” This product is not only waterproof, but it’s low cost as well, providing owners with peace of mind that their building is protected while also protecting their bank accounts. 

Listen to the rest of the podcast to learn more about gravel roofing restoration.