Pitch pans are used to seal around pipes penetrating the roof. When pitch pans are not maintained or they are filled with materials that do not seal well, water will run down the pipe and through the roof. This is the most common maintenance problem on flatroofs today.
Blown-Off Chimney and Vent Caps
High winds can cause these caps to blow off allowing water to get into the pipe. The simple fix is just to install a new cap.
Standing Water on Commercial Roof
Sometimes this is due to a clogged or blocked drain but most of the time it is due to poor drainage. If the roof is “dead-level” or if there are low areas, the best way to solve this problem is to install a taper insulation system at 1/4″ of slope per foot of roof, and put a new roof over this. If the drain is clogged it may require a plumbing contractor to unblock the drain.
Roof leaks are not always roof leaks. Sometime the mortar in masonry walls deteriorates and falls out allowing moisture to penetrate the wall allowing water to get under the roofing system making it look like a roof leak. Masonry walls can also become porous and absorb water like a sponge. Masonry sealant is the best way to protect brick walls and tuckpointing is the only way to replace mortar that is damaged. (See our partner page for a mason)
Clogged drains can be a huge problem for a low slope roof system. Water backed up on the roof is very heavy and can cause stress to the building, the roof structure, and the roof system. A regular roof maintenance program will alleviate this significant problem.
The flashing that is installed on walls and curbs usually fails before the roof system does. That is because most of the expansion and contraction takes place here causing the flashing to tear of break. Often the top of the flashing is not terminated properly and this too breaks loose allowing water to enter. It can also cause damage to masonry walls and to the interior of the building.
Membrane roofs that are heat-welded or glued together can sometimes split apart with expansion and contraction. Often it is due to a weak seam caused by poor workmanship or, if it is an older roof, it will just lose its elasticity and the weaker areas will break loose.
Metal Edge Breaks
Often the field sheet of the roofing system is sealed to a metal edging that is installed along the outside perimeter of the building. Expansion and contraction can cause the membrane to break loose from the metal edge. This allows moisture to seep under the roof system and down the wall of the building causing structural damage to the wall if it is not corrected.
Sometimes roofs leak just because the roofing system was installed improperly. This is especially true of flat roofs because water will accumulate on the roof during heavy rains causing defective areas to leak because of the enormous water pressure on the roof from the standing water.