Hello HAIL hole ? Heck no hail hole, that’s one of three……….

Hello HAIL hole ? Heck no hail hole, that’s one of three………. what?


Have a look at this hole, looks like an impact puncture from this angle. Hence the ‘hail’ in the title. But if hail did this ‘damage’ there would be lots of other impacts as well. Then I found another one (2nd photo) ;

Roof hole but not a hail hole


And this second one was similar but had a new wrinkle;

A new wrinkle

Now this one has a debris ‘bulb’ strainer, the type normally used to keep leaves and other junk out of the drains for flat roofs. This roof is definately not flat and needs no drains here, right?

You can also see what probably is flashing under the shingles at that tab slot below the ‘hole’. So it’s not likely to be impact damage, it was intentional.

So what is it?

Well , though I had a good idea about it,the mystery was solved when I got to see the attic side of things;

plumbing stack


Well this is what you see from the attic side, and it’s no impact hole, hail or other wise. Neither is it a roof drain, though it will drain a few square inches of the zone immediately above it (them, remember there are three.).

What they are is plumbing stacks (vents) for the 5 bathrooms/powder room and kitchen of this large home.

The good news is that there are no leaks in this very non-standard installation. (so far)

Look closely at the copper parts. You can see that there are 2 sections. The top one is sleeved into the lower one (very tightly) and it has a soldered seam facing us, the ‘up-hill’ side. That’s because it is not a pipe section.

It is a flashing boot that has been installed up side down.

Here is a similar product made in galvanized metal and available at Home Depot and other hardware suppliers;

This is a modern galvanized version of ther same thing.

This is meant to be installed uptight on the surface of the roof with the plumbing stack pipe coming out the opening and extending up to at least 18″ above the roof.

The edge where the pipe comes out can be sealed but a better treatment is a counter flashing sleeve extending down from the top of the pipe to a point a few inches below that joint.

The top of the sleeve has a smaller opening than the pipe diameter, which works fine for it’s function of letting in air, but it restricts rain and incidental debris entry.

The top of the flashing base gets tucked under the upper shingles and the lower end is meant to be on top, just like it was a shingle itself. That’s how it’s designed to work.


So these three holes on this roof are incorrectly installed amateur or non-professional work. The materials have been used inventively but incorrectly.

The only saving grace is that the work was done carefully enough so that there have been no leak problems to date.

But there have been problems. I asked the house keeper who was present at the time of the inspection if the drains made noise or here slow to drain. Yes to both symptoms was the answer.

I then asked if it was worse under heavy rains and through the winter snow season? She said Yes, how did you know that?

The answer is of course is that’s when those roof ‘holes’ are blocked with snow, leaves or taking in high volumes of rain water, so the ‘stacks’ can’t draw air to allow the drains to operate and run freely as they should.

The roof shingle surface is new and in good shape. But the flashings do not lap over the lower shingle courses so sometime in the next few years water will be getting under those shingles, risking damage to the roof below those ‘holes’  and of course eventually admitting water to the homes interior.


How many real estate professionals who are not inspectors would identify this condition and recognize the problem and realize that correction is required?  How many homeowners and buyers?

There is no book or course out there that will explain any mistakes, errors or ‘inventive’ details that may be found. You need experience working for you. You need analytical thinking applied to your inspection., not just a check list.

When you are looking at, or investing, in a home or property in the Montreal or the surrounding area you know who to call.


Original blog post on ActiveRain: Link to Blog Post