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Sideways Leaks

April 14, 2016

Sue & I came home from last year’s holiday trip to find our dock with an enormous puddle of water stretching from the dock door over to our refrigerators (about 50′). Suddenly I worried that the Phase 2 Roof Replacement less than two months old had failed miserably and a new un-tarped leak was making it all the way down to the first floor. I immediately went to second floor, and it was dry as a bone. Puzzling.

I inspected the dock door and thought maybe all the water came through cracks in and around the door. But it would have had to have blown very hard with a lot of rain to get the huge amount of water we had on the floor and trailing away.

Since it was not raining at the time, I would have to wait until the next big rain to see exactly where the water was infiltrating.

Several weeks pass before our next big precipitation, but I was finally able to watch during the rain and see where water drips started, and for a couple minutes I didn’t understand it. The leaks were appearing right in the middle of the brick wall in the dock! As if someone was standing outside in the alley spraying high-pressure water at the wall, and the water was coming in sideways through the wall. But I eventually figured out that the downspout from the roof was involved. There is a point where the downspout makes a bend into a vertical recess in the brick wall before it goes into the ground, and this bend has developed some holes.

I noticed this back in the fall when we setup our DIY trash chute for the first time.



I didn’t think much of it – I saw that a few big blobs of roofing pitch had jammed themselves into into the holes, and back then didn’t think it would lead to an issue.

So while still raining, I popped outside in the alley and found the water that dropped from the roof scupper was spraying all over when it hit this “bend” because now the blobs of pitch were gone and it was a free-for-all and the rain water went everywhere. Which then caught on the rail for the dock door, and with the mortar being soft and probably containing a few holes, found its way to the inside.

When it was finally warm enough, repairs were in order.

I set up a ladder and inspected the situation. On closer look – this bend had been a problem for quite a while because there was evidence of several layers of repairs. Bad repairs, and now it was a mess. I peeled off the old layers, and strangely they felt not much thicker than aluminum foil. As if the last repairman thought Reynolds Wrap would take care of the problem.


Super-thin old repair material – you could poke a pencil through this.


The hole in the bend was now quite gaping:

The "bend" with old repairs removed.

The “bend” with old repairs removed.


I kept peeling and cutting, through layers of old aluminum and dirty globs of silicone. I needed to get rid of all of the loose and craggly bits if any new repair was going to take hold.

Here's the bend free from crappy old repairs.

Here’s the bend, free from crappy old repairs.



I also trimmed the edges of the original copper with shears to make everything as neat as possible.

Any new patch would also need sealant around it, so I had to make sure the old copper was as clean as possible so the sealant would stick. So I used a wire wheel on an angle grinder to remove as much of old coatings as I could. I realized it couldn’t get it back to 100% clean copper, partly because of time and partly because of the position – I was high on a ladder which made everything a little more difficult.

All the work was done at the top of the ladder about 15' above the alley.

All the work was done at the top of the ladder about 15′ above the alley.

Okay – with the prep on the old stuff done, now to work on the repair.  A couple things; this repair was not going to be “permanent”, as in, beyond our lifetimes, which is what I normally aspire to. Because the long-term plan for this wall was to get opened up for a drive-in garage, this downspout would eventually be relocated or replaced. Not sure when though. Which led to thing #2 – this repair needed to be “just good enough” to last 3-5 years, which was a little difficult for me mentally.

In this “in-between” repair mode, I decided that the sheet material at least needed to be copper, because the original downspout is copper and there would be zero galvanic action if the repair was the same metal. (Click to learn about galvanic corrosion.)

Buying a sheet of copper seemed wrong – weren’t there tons of old copper around BAB? I pulled a lot of old copper flashing out of the old roofing projects – but those seemed to not have the square footage – they were only 10-12″ tall by whatever-length… but then I remembered that HUGE sheet of copper I uncovered that was lying flat on top of the concrete roof, during our last phase of new roofing…

Uncovered this huge sheet of copper beneath old roofing,

Last fall I uncovered this huge sheet of copper beneath old roofing,



I took some dimensions of the “hole” in the downspout and quickly guess-timated the size I needed. After whacking off the appropriate chunk of sheet material, I brought it down to my metal workbench.

The raw material for the new patch, extracted from the roof.

The raw material for the new patch, extracted from the roof.


The old copper sheet had some spots that had heavy coatings of pitch. It needed lots of cleaning. Since I didn’t want to clean anything I wasn’t going to use, I laid out the limits of how much copper I needed (based on the hole, and folding the sheet on the sides) and squared up the sheet to cut away the nastiest areas so I didn’t have to clean them.

I scored out the area I needed and cut away the scrap with tin snips.

I scored out the area I needed and cut away the scrap with tin snips.

I did some rough flattening, with a metal working hammer. The goal was to just get it flat, but not perfectly.

Rough-flattening the old copper.

Rough-flattening the old copper.

After flattening, I thought I should clean the copper as much as possible. I used some solvents to remove the pitch and tar, but there was still some deep patina and tarnish. I used a wire wheel again. In combo with the solvent.

Combination of solvent and wire wheel cleaned the old copper.

Combination of solvent and wire wheel cleaned the old copper.

It was coming clean moderately fast. Then I realized – if I cleaned this copper all bright & shiny, and then stuck it on the building in the alley, it would practically be an advertisement for copper thieves. So I stopped cleaning.

The minimal amount I needed to do was just clean the copper enough so that a sealant would stick to it.

Once I was satisfied with the cleanliness of the copper sheet, I figured out the shape I needed to fit onto the downspout and “unfolded it” in a backwards-origami-style and scored the lines where folds and cuts would occur.

The patch laid out and scored where folds would occur.

The patch laid out and scored where I would need to fold or cut it.

There is a specialized tool called a “brake” that fabricators use for folding metal. I’ve never owned one and the last time I used one was in 1974 in 7th grade shop class (when we weren’t afraid of kids using real TOOLS!) In a pinch I had to improvise so I used some clamps and metal straightedge to fold my patch.

Setting up a "fold" on the copper.

Setting up a “fold” on the copper.

With proper setup, tight clamping, and a rigid straightedge, the fold is actually pretty easy. Of course – the thicker your metal, the harder it is. This copper, which was pretty thick, wasn’t too hard to bend.

The first fold is the easiest.

The first fold is the easiest.

I’m going to skip the minutiae of snipping and folding and testing the shape of this patch – it took a lot of careful planning to make a three-dimensional patch as needed.

But here’s the version I got to that I thought was reasonable enough to test and see how well it fit.

The patch folded enough ready to test for fit.

The patch folded enough ready to test for fit.

So I brought it up to the top of the ladder and slid it onto the “bend” to see how well it would fit.  The dimensions seemed to work out well, and there was plenty of overlap for fasteners and enough area to apply sealant.

The new copper patch - test fit and ready to go.

The copper patch – test fit is good.

Back at the workbench, some final touches were to fold over the corners – where they overlap would be the best place to fasten it to the original downspout.Imagine those paper Chinese take-home boxes – the sides where all the folds are.

Ready to install...

Ready to install…


But… what to attach it with?

At one point I thought I could just GLUE it in place with silicone sealant. But it can take a while to set up and the whole thing might fall away. So some kind of screw or something was needed. IDEALLY – it should be a copper fastener – I know small copper sheet metal screws are available but I didn’t think I had any. I wasn’t ready to run to the store just for those yet.

Then I thought: maybe the Robert Vavra treasure has some copper rivets!? I had a recollection that there was a whole drawer of pop rivets. So I scanned the drawer fronts, carefully labeled…

Vavra dedicated [nearly] a whole drawer to pop rivets

Vavra dedicated [nearly] a whole drawer to pop rivets

And found one with pop rivets. HOPEFULLY there was both a tool, and if I was really lucky, some copper rivets.

Super score! The pop rivet tool, AND copper rivets!

Super score! The pop rivet tool, AND copper rivets!

Woo-hoo! Everything I needed was in there. The Uber Bench pays off again.

And another freebie, when our good friend PTK moved to D.C., he gave me a bunch of random silicone sealant tubes. I sorted through them and the most suitable colors were white, almond, brown and black – so I chose brown to seal up the joints.

I gooed the silicone liberally, then drilled holes for rivets, popped them in (sorry no closeup photos – sometimes I get too involved in work and forget to document) and voila – all done!

Final photos:

Patch completed.

Patch completed.



Closeup of the patch.

Closeup of the patch.

So the silicone was messier than I preferred, I felt a little rushed and it was a little tricky to do from the top of the ladder. But as I said earlier, this is a short-term fix and will likely be removed sometime.

A couple weeks after I installed this patch, we got a good rain, and there was no more water coming through the dock wall!

5 Comments leave one →
  1. Tom permalink*
    April 14, 2016 11:56 pm

    Yep, we have copper thieves. They’re crafty and will use whatever means to pull down copper, without ladders.

  2. Stefanie permalink
    April 14, 2016 9:59 am

    I hear ya on the copper thieves. In our ‘hood, they even take aluminum gutters/downspouts. 😦

  3. Jim Peterson permalink
    April 14, 2016 9:07 am

    Nice job Tom! Ah, shop class where there was potential dismemberment….good old days! I’m not sure if you had the same shop teacher as I did, but I recall him having one missing finger, maybe even two. And yet, we all signed up for the class.

  4. Rick Peterson permalink
    April 14, 2016 6:18 am

    Good job Tom.
    You’re funny, copper thieves. How many thieves walk around with an extension ladder ? As I tell my customers, if you see a person walking down the street carrying a ladder, ask them what’s up.


  1. BAB takes a leak | B. A. B.

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