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Help! My Cupola Leaks

Help! My Cupola Leaks

If you have a leaking cupola, I can understand why you would be looking for help. Only twice ever have I gotten feedback from a client with a leaking cupola. In first case client’s builder somehow neglected to read installation instructions in Hansen Pole Buildings’ Construction Manual.

Aforementioned builder decided to defy Isaac Newton (Laws of Gravity) and installed cupola and flashing directly to top of roof purlins, then butted steel roofing and ridge cap up to cupola. According to Mr. Newton, things like water will flow downhill, resulting in water leaking around said cupola.

In today’s dilemma reader PAT from TRAFALGAR writes:

“If possible I would like a direct response via email

My 30×40 pole barn was completed in September. When it rains it get very small amounts of water leaking in through the cupola. Is this normal? Should I require my contractor to repair, under the warranty? Will repairing result in other problems?”

As much as I would like to have sent a direct response via email, Pat neglected to share his email address. For those who are curious, Pat did not invest in a Hansen Pole Building.

Water leaking in through or around a cupola would be abnormal. Your contractor should indeed repair it and a proper repair should not result in other problems.

Most often provided cupolas are pre-manufactured. If site built instead, it should probably be replaced with a manufactured unit.

Pre-manufactured cupolas come with either standard flashings or a universal base. Universal bases do involve a slightly greater investment, however save a significant amount of labor as well as greatly reducing (or probably eliminating) chances of a leak. Many builders are short sighted and will go the cheaper route, ignoring end result challenges.

Assuming the builder wants to fix rather than replace – find the leak (sounds pretty simple, eh?). This requires a hose and someone to stand inside and tell a person upon the roof when water starts coming through. Begin with downhill edge flashings, run a pretty good stream of water onto them (one side, then other) for a minute or so. Even if the leak happens to be along one of them, keep checking along the way, as it could be multiple points. Next, check ridge cap side flashings, using the same process. Then check each side of the cupola individually (letting water run down from cupola roof).

If a leak exists, it should have shown up in the hose test. With leak isolated, a repair can be done using the best silicone caulking money can buy. If a flashing edge happens to not be sealed to the roof, Emseal AST expanding closures work quite well to fill those gaps. https://www.hansenpolebuildings.com/2016/03/emseal-self-expanding-sealant-tape-closures/