Valley gutter: Trying to think of a neat solution

[GMM]

Sorry, but this has turned into a long one (ooerr vicar).

My place has a coach house, aka a 2 storey garage, which is paired with a similar structure next door. The two roofs have a valley between them and this was relined not long ago by my neighbour in zinc.

Every last leaf or bit of loose moss in the city seem to find its way into this. Consequently, it blocks, fills and overflows into both sides. I was reminded of this at the weekend whn I found a drip, so got up there and cleared a clot of moss. Soon, it will fill with leaves and, if we don't keep an eye, the same will happen.

The key to this problem (in my view) is the outlet, which is a running outlet before the end, the end of the valley being blocked by a full height (~6 inch) vertical 'stop end' formed to finish the zinc.

Of course, there's no sunstitute for regular maintenance but I would rather devise a means where the need for this isn't indicated by a leak inside the strucure, ideally without making a huge meal of it (ie strip all the roof tiles and form a deeper valley). Had a chat with my neighbour today and he's happy with whatever solution I come to.

Now, I reckon that reducing the height of the stop end would do the job and it's tempting to just cut a deep groove in it. That way, a blockage in the outlet would lead to water spilling out of the end, which could be spotted and the blockage cleared.

Easy-peasy....but: I would like to ensure that when this overflows, the water falls clear of the brickwork, so really need a bit of an extended (3 - 4") lip on the groove and I'm trying to think of a way to form this neatly. So far, I've thought of:

1 Getting another piece of zinc and forming an extended spout then fixing this to the cut end stop. Probably the Rolls Royce solution, but I'm not sure I fancy my chances forming a decent solder joint at height in winter (I know about soldering zinc and it's a bugger).

2 Cutting a circular groove and laying a piece of grey mini drain pipe in this horizontally, with about 6" protruding.

3 As 2 but with a piece of mini-profile plastic guttering. (I can't seem to find a local source of zinc drainage or I would use that instead of plastic)

The issue with 2 and 3 is securing the plastic pipework so it doesn't slip out or in. A pipe or gutter clip might stop it slipping out, but would look a bit of a bodge on the outside. Basically, I want to form something, bet up there, cut the groove, and clip my piece in.

So....Any bright ideas chaps? (Or is everyone glued to the footie?)

[harryagain]

You can buy mini "tunnels" made out of mesh that fit over gutters etc and filter the water and keep the rubbish out.

[Kevin]

Could you cut a hole in the vertical stop-end, then fit either a shower waste, small basin waste, or even a tank connector, each appropriately connected to a short length of plain pipe?

[Chris Hogg]

Consider pop-riveting the extended spout, applying silicone sealant to the mating faces before doing the riveting, to seal them?

[GMM]

Sounds like a good plan. Now all I have to do is find a source of a scrap of zinc to form it from!

[Harry Bloomfield]

I would also look at stopping the moss forming in the first place. Bare copper wire strung across at the highest level, so the copper sulphate washes down the tiles, works well here.

[fred]

Sounds like a great idea, I'd be inclined to add a little compliance to the joint too by way of a rubber gasket and smear this with silicone for a belt and braces approach. Stainless self tappers may be better than pop rivets as they're not hollow ;-)

Also, I assume there is some kind of guard on the downpipe and that is the point where clogging occurs? Here it might be an idea to create a longer (up to a metre long) sloping grill that would provide a larger surface area that would need to be blocked before the gutter/drain would block.

I take it there is a preference not to use a full length mesh guard suspended in the valley?

[GMM]

Indeed: I think that will help, although in a few weeks there will be an enormous collection of leaves there, which is the worst aspect and wouldn't be affected.

Of course, getting to where the wire needs to be strung is another chalenge given the complicated geometry of the location .....

[GMM]

And self tappers means that I don't have to turn the garage upside down to find my rivet gun!

Yes - I was thinking of something like that, eg a length of the 'right' mesh (not too fine, not too coarse) shaped to space over last bit (maybe

2ft) from the outlet. Of course, it would still clog up in the end, which is why I want the spill to go over the end instead of up the sides and into the structure, but it might increase the time between clear-outs.

Given the difficulty of access, it would be a bugger of a job to get up to the 'far' end (about 40 ft) to clean the guard compared with letting the cr@p get washed down to the front then scooping it out off a ladder. Although the valley lining looks quite robust, I'm not sure it would do it a lot of good to walk along it every few months.

[Chris Hogg]

I assume you're correct in saying it's zinc, and not lead which might be easier to source. An alternative for the spout might be aluminium, copper or even a bit of lead flashing, although clamping two dissimilar metals together in a wet environment runs the risk of galvanic corrosion.

[GMM]

Yup, definitely zinc, as it turns out my neighbour (a retired mechanical engineer) actually built and installed it, and a very tidy job he did of it too, despite this small design fault.

I suddenly had a thought on Saturday: I was driving past a scrap metal merchant so pulled over and asked. He happened to have a big pile of scrap zinc roofing sheets. Pulled out a fairly good one sized, about 4 ft by 18 inches at a charge of.....70p a kilo, a total of 1.40, so I gave him £2, feeling generous (!). It scrubbed up easily enough and it took about 10% or less of this to make the spout. An hour or so later, I had my spout. Haven't fitted it yet as I need to see the neighbour and find out if he still has any of the paint he used - It's a lot simpler to paint it off the job then mount it and cut the end stop after fitting.

Anyway, the moral of the story is, if you need an offcut of metal of any sort, your local scrappy might be a place for a bargain.

Now...What am I going to make with the rest of this sheet of zinc?