Five Common Leak Sources NOT Associated With The Roof

It all starts with seeing a small drip of water or a stained ceiling tile. The little nuisance that a roof leak is to a building owner always is cause for concern to get addressed and repaired before it ever turns into a larger major problem. Many times a real estate building owner will call for a commercial roofing contractor to service a building for roof leaks they see but they are not always necessarily coming from the roof itself. Yes it may come from the ‘roof area’ but there are several other key things that need to be considered and looked into which a majority of the time, can be major causes of roof leaks in the commercial building world.

1. HVAC Units – Air conditioning units are many times found to be the culprit of a roof leak. From a backed up condensate line, to a rusted out drip pan, or a unit that is not properly sealed – HVAC units are common causes of every day roof leaks on commercial real estate buildings. Taking the time to locate a leak from the inside of the building and seeing if it lines up with a mechanical unit on the roof surface is a great step in determining if the HVAC unit is a possible cause. Also look for holes or missing screws on units where rain water can easily gain access into a unit or penetration and make its way into a building.

2. Cracks in Walls and Wall Joints – If a leak of water appears to be coming down from an outside wall of a building, this may be caused from cracks in walls or bad mortar. One of the most common sources of leaks on the wall of a building are found at wall joints especially when the sealant at these areas crack and deteriorate over time. Always keep regular observation on the upkeep of a buildings exterior walls and if cracks/voids start showing in wall areas, they should be addressed right away.

3. Plumbing from Roof Drains – As buildings age, the plumbing and seals of a building often need to be inspected regularly as plumbing seals can deteriorate and wear over time. If a so called ‘roof leak’ is coming from an area with a roof drain or drain pipe located near it, there can be cause for concern that the leak is actually associated with the plumbing of a building. This may take thorough examination by a roofing contractor and plumbing contractor together but once it’s determined to be coming from the roof drain bowl or the roof drain line – a plumbing contractor will have to take it from there. One side note to consider if the leak is at the drain bowl / pipe connection – a metal retrofit roof drain might be an option to fix the issue.

4. Condensation and Moisture – If you ever walk into a cold grocery store or temperature controlled environment, the temperature from cooling equipment can cause major moisture issues which can lead to condensation and moisture drips. Most of this comes down to the design of a buildings air cooling systems via piping or duct work that may be up against the roof deck in the ceiling but it is usually very easy to identify. If stained ceiling tiles or drips of water are coming from areas with duct work or pipes in the ceiling area, the main thing to monitor is if these drips of water are occurring during normal sunny days where no rain has been present. If this happens to be the case, a professional HVAC technician might have major issues to address in the insulation and function of the air cooling system in a building.

5. Foundation Water Entry – There are times when a commercial building owner comes into their building one morning and they find water all over the ground or up against walls. A common source, especially on older buildings is that the water may be coming in via the floor or wall-to-ground areas of a building. If the puddles of water are large or extremely saturated but no staining of ceiling areas or old water marks are found, this foundation issue may be the main problem. It would be wise to wait until a good heavy rain and see if it actually leaks in the rain from the roof at all.


Roof leaks or leaks that may be believed to come from the roof can be a common occurrence in the commercial real estate world but having proper professional contractors who know how to investigate and sort through the different water entry items of a building are a great resource to have.


For professional commercial roofing services and consultation for a real estate building which is facing leaking issues – contact one of the fifteen (15) national commercial roofing offices of Peach State Roofing Inc. Their information can be found on the locations page of our website.