A Word about Roof Tops

A Word about Roof Tops

For most of us, the rooftops of our restaurants are not a normal part of our preopening or closing walk through. In fact, a trip to the roof often means something is wrong: i.e. a leak in the roof, an A/C unit not working, or the exhaust fan making a funny noise. It isn’t that any of us are neglectful of the condition, it’s just something fresh on our minds. Any of us that have replaced a roof top in the recent past know first-hand, that it can be one of the largest investment we will make, and maintaining a new roof top quickly becomes top priority.

Your kitchen exhaust cleaning provider’s job is to clean your kitchen exhaust system to bare metal. Most of us only see the KEC Company every three months, so it is important to keep grease off of your rooftop in between these cleaning. In fact, if grease is left on your rooftop, it will void the warranty that comes from the roof manufacture.

Most exhaust fans come with a metal box attached to the side often referred to as a “grease box.” The bottom of the fan bowl has a drip spout coming out which flows into the grease box. The grease box is fire, wind, and water resistant and is a good solution for many lower volume applications. Sometimes, however, you will find small puddles of grease underneath the grease box. This happens for several reasons like the spout not dripping directly into the box which is an easy fix. The box is possibly overflowing which means you should look at your cleaning frequency or get a bigger box. A more common issue is that as it rains, the box fills with water. Grease and oil will float, and as the rain fills up the box, it will push the water out and onto the roof.

Omni-Side-Kick-259x300 Omni-Grease-Gutter-294x300

In the case you find your grease build up is larger than the receptacle, you can look into what is called a “Sidekick.” A good feature with the sidekick is not only the larger capacity, but it comes with grease absorbing filter. This filter is specially designed to absorb only grease and allow water to filter out. This video gives a little idea of how the absorbent materials work (fast forward to 7:30):

Grease Gutter Video

Many times we find that the grease absorbent filter reaches its life faster than the scheduled frequency or that grease is seeping out of the fan in more places than just the drip spout. Instead of box or gutter style container, many companies are utilizing an entire roof top protection system. This entire system rests on the roof top itself and surrounds the entire fan with multiple layers of grease absorbing material, grease dispersing material (so the oils do not pool into on place), and fire retardant material in case of combustion to contain the flammable material. Often times, these are significantly higher price points, but are quite cost effective compared to the replacement of the entire roof top.

Whatever your grease containment needs regarding the rooftop, get with your trusted Kitchen exhaust cleaning vendor to discuss an individualized solution.

Evaluating the Cause of Grease Build Up on Your Roof Top

Evaluating the Cause of Grease Build Up on Your Roof Top

There is a common misunderstanding between kitchen exhaust cleaning service providers and facility managers regarding grease build up on their roof tops. Most restaurant or Facility Managers feel that if there is grease on their roof top then there must be a deficiency in the work being performed by their service provider. Often this can be the case. However, there are some cases that grease can accumulate on your roof top in between services. There are three different ways that grease can accumulate on your roof top. It is important to be able to evaluate whether the service being performed is below par or if there is a need for preventative maintenance at your facility by knowing how grease accumulates and what to look for.  

 The first way that grease can accumulate on the roof top is through poor waste water management during the cleaning process. This is the easiest of the three to evaluate, though it does require follow up by the restaurant staff. During the cleaning process there are a few ways that grease can accumulate on the roof top. An example of poor waste water management is when a technician is spraying the bottom of the fan blades with the fan off the duct or when the fan is held open by the hinge kit. What typically can happen in this example is the technician sprays the bottom of the blades while allowing them to spin. By doing this, the blades spin and grease and water are slung out of the fan on to wall, roof top, A/C units, etc. This can cause multiple problems but typically can be detected easily. When evaluating your system to see if this is happening, you need to look for a spray pattern the size of the bowl of the exhaust fan. If this is occurring, grease will be accumulating in a concentrated area in the pattern of a “v.” The other way grease can accumulate is if the technician allows the waste water to run out of the exhaust fan and on to the roof top. This can be detected by evaluating how the grease is accumulating from the fan. If the grease is fairly light and extends down the roof toward the drain, then the grease accumulation was probably caused by poor waste water management. 

Grease Build up from Poor Waste Water Management

The second way grease can accumulate on the roof top is through grease leaking from the fan between services. This can happen for multiple reasons such as excessive rain between services, improper seals on the joints of the exhaust fan, and a bad seal between the fan base and the duct curb. When this happens, grease leaks from around the base of the exhaust fan, from the seams of the reservoir at the base of the exhaust fan, or from grease overflowing from the grease collection box mounted under the drain of the exhaust fan. All of these are fairly easy to detect. In most cases if you are getting grease accumulation between services, the grease will be accumulating in concentrated areas next to the fan. On roofs with a slight slope the grease can spread a little due to rain water. You will also be able to tell where the grease is leaking by looking at the side of the duct curb under the fan and at the grease collection box to look for drip marks where the grease has been leaking from. In this situation, we recommend to our customers that a preventative maintenance product be installed to protect against roof damage. There are many types of roof top containment products on the market, but your service provider should be able to walk you through your options and what works best for you. 

Grease Build Up on Roof top

The third way grease can accumulate on your roof top is through airborne particles. These can accumulate on the roof top due to the frequency of your system not being set properly. Typically when this happens grease is collecting in the base of the exhaust fan in a liquid state. Once the grease fills to a certain level, the air flow starts to sling the grease out of the fan reservoir and into the air causing grease to accumulate throughout the roof top in the form of small little drops of grease. At times, it can also accumulate in the form of a light film. If this begins to occur, you need to contact your service provider and discuss evaluating your frequency over the next several months to get it set properly where the problem will not continue. 


Your roof top is a part of your facility and can get overlooked. Understanding how grease can accumulate on your roof top and the ways to evaluate how it is occurring can save you thousands of dollars in unnecessary repairs. If you are experiencing grease build up on your roof top you should contact your service provider and set up a time to look at the build with them. As we say at Hood Boss, “Expect what you Inspect.”

If we can be of any assistance to you please do not hesitate to call at 972-704-1812 or you can visit us at our website at www.thehoodboss.com.