Waterproofing SurveillanceBy Brian Rhodes, Published on Nov 27, 2012
Water destroys countless surveillance cameras each year. As big as the problem is, water remains a huge issue for surveillance systems year after year. What can be done to mitigate the problem? This report takes a look at how to successfully waterproof surveillance equipment, including:
- Limiting Exposure to Water
- Sealing Openings
- Maintaining Gaskets
- Waterproofing Sealants
- Keeping Cables Dry
Water Infiltration Core Problems
Three inargueable realities exist when hanging cameras near water:
- Water Kills Electronics: Because water is a conductive liquid, coming into contact with electrical circuits is damaging in unpredictable ways.
- Water Freezes: When water turns to ice, it expands. This expansion in vulnerable spots can lead to deforming or cracking of housings. Even if the ice itself does not damage electronics, the housing damage it leaves behind can provide opportunities for water leakage during subsequent precipitation.
- Water is Organic: Even if water does not directly damage the camera, it carries bacteria and biology that can grow unchecked inside of housings. If the interior of housings are able to become damp, they can become mini-greenhouses that host a variety of plant life. Since the utility of cameras are limited to what they see, rogue organic material smoking up lenses or covering housing glass is especially troublesome. The image below shows an example of a housing affected by algae growth. Take note of the attempt to clean organic film off the front enclosure glass:
Fundamentally, any camera that may be exposed to water should be enclosed by an IP 54 or greater housing. The universally 'ingress protection' ratings are used to quantify how resistant to water infiltration a housing is designed. The lowest acceptable (IP54) rating means that splashing water will not damage the contents, but for cameras mounted in more vulnerable or exposed areas call for higher (IP65/66) ratings. The chart below provides a brief interpretation of 'ingress protection' codes:
Installation Approaches to Waterproofing
Observing a few smart installation strategies will help prevent and ignificantly reduce the impact of water damage.
- Limit Exposure to Water: Hanging cameras where contact is minimized with water is important.
- Seal Openings: Any holes or gaps in the housing invite water seepage and must be minimized.
- Maintain Gaskets: Rubber, cork, or plastic seals must be clean and free of cracks. Gaskets are critical to keeping water out of cameras
- Waterproof Sealants: Smart application of waterproofing sealants like silicone keeps water out of housings and mounting surfaces alike.
- Keeping Cables Dry: Keeping video cable dry is an often overlooked aspect of waterproofing, but is just as critical as the camera itself.
Installing the camera according to manufacturer recommendations is always an overarching precept, but is even more important regarding waterproofing. Aside from simply installing non-outdoor rated cameras where they might be exposed to water, assembling the camera into the housing, hanging the housing correctly, and not gouging or damaging seals during install are critical to observe to prevent water damage.
In the sections below, we examine each strategy and illustrate its importance in the field:
Limit Exposure to Water
An obvious strategy, but arguably the most effective, is to mount cameras where the possibility of water gathering is unlikely. This includes mounting cameras under overhangs, on soffits, and out of direct exposure to the sky. Even 'optional' housing accessories like solar shields have value in protecting against water infiltration.
Even when hanging cameras in a protected fashion, gaps or holes can still invite problems. For example, a common problem in many outdoor dome cameras surrounds the mounting threads - if the threads are not gasketed or sealed with teflon tape during installation, even the minute gap between screw threads will allow rainwater to enter housing and potentially seep into the camera itself.
It is also important to consider the impact eventual weathering will have on a new housing. Even when housing material tightly overlaps itself, like the example of a sun shield or solar protector, it can warp or buckle due to weathering and create gaps where none was initally apparent. In the image below, we have highlighted examples of this problem on the same housing:
While the mounting elbow is partially sealled against water, the threads on the backside of the elbow also need sealing. In addition, the slightly warped sun shield on the top of the dome could trap water and potentially damage the housing when frozen.
Filling voids, holes, and gaps with weatherproofing sealant like Acetoxy Silicones or Coax Seal putty helps to prevent damage. As a general rule, the potential risks of applying 'too much' sealant is minimal. Common areas calling for sealant are:
- Cabling Holes/Pathways
- Screw Holes
- Gaps between Enclosure/Mounting Surfaces
The image below shows a common application of waterproofing putty to where a cable passes into a housing:
Some housings feature weatherstripping to keep water out of housings. Ignoring the affects of dirt, grime, and sun damage on these seals can result in failure to keep water out of camera housings. Many enclosure manufacturers list recommendations for maintaining seals - often including keeping them pliable with the periodic application of mineral oil or white lithium grease.
The image below is an example of how extensive water damage can be with gaskets that have failed:
Keep Cables Dry
Finally, a commonly neglected consideration in waterproofing is minding the cable runs behind the camera. Cabling should be run in water-tight conduit and connectors - troubleshooting water damage in connectors and cabling can be especially time consuming. The image below shows video cabling run atop a roof, where it not only is directly exposed to precipitation but is residing in a drainage gutter:
Even when cable is not run in a haphazard manner, it is important to consider the impact of wind and animals relocating cabling to exposed locations.
When service junctions are required, engineered IP65 rated 'butt connectors' like the style shown below, are designed to keep water out of connectors even if submeged: