Code requirement for depth of Counter Flashing and material sealant

chimneyflashingmasonryroofing

Okay, I've got a recently-installed standing-seam metal roof. The roofers ground out the brick in my chimney to install counter-flashing. Recently there was a big leak around the area of the chimney. We had 2.1 inches of rain the night it leaked.

Now, the roofers came out to inspect the cricket, and they think it's the chimney. I've had two masons (one more scheduled) come out and look at it. Both said the old mortar is fine, but it would be a good idea to tuck-point and seal the chimney anyway, and the cap could use some work. Neither seemed to think the chimney was letting in that much water.

The second of the two masons was very concerned about how the roofers installed the counter flashing. To him it looked like they only got about 1/4" of the metal under the top brick, and filled it in with mud. He say's this needs to be much deeper, and using a high grade polyurethane instead.

My question is, is there anything in the International Building Code about installing counterflashing in masonry? I've done some looking, but haven't turned up anything official. Though every source I've seen recommends a minimum of 3/4".

Depending on how far I get with the roofers and masons, I may end up just re-doing the flashing myself.

Best Answer

The IRC covers roof assemblies briefly in Section R903 but it's not very specific.

It does say (and this is a common theme throughout the IRC and virtually all building codes):

Roof assemblies shall be designed and installed in accordance with this code and the approved manufacturer’s installation instructions such that the roof assembly shall serve to protect the building or structure

So if you know what specific product was installed and can find installation instructions from the manufacturer (maybe call them?), then you would have something more specific to point to.

It may also be worth calling your local building inspector and find out whether there are any more specific local building code rules that may be applicable.