Water dripping from woodwork

[Munch]

I recently noticed a damp patch on the concrete floor at the front of the house. The boiler is installed in the loft and the condensate drain has been poked out of the loft to empty the condensate onto the roof, where it makes its way down to the guttering and off on its merry way.

I assumed that the guttering was full of leaves and just needed clearing but it's clear - then I discovered that the water/condensate is not getting as far as the guttering and is actually dripping from the woodwork. The end of the condensate pipe and the location where I've seen drips forming are both arrowed in the two photos below:

What's likely to be the problem? What's behind that woodwork and in the 'overhanging' section - just empty space?

[Bob Minchin]

At the risk of stating the blindingly bleeding obvious you have a leak somewhere. Maybe the outlet has blocked and the pipe work has not been properly solvent welded or repeated thermal movement over the years has parted one of the joints. You need to get up there and trace it through or maybe easier fit a new pipe run as trying to solvent weld old dirty pipe might not be 100% successful.

It clearly has been working until fairly recently as the acidic condensate has been running down the tiles. Not sure what the long term effect on the concrete tiles has been - wonder if they have gone porous? A less pretty but sounder solution would be to run pipe down the roof slop and direct it into the gutter. If the tiles have become porous, painting that strip with bitumastic paint might save having to replace them.

[Munch]

No, there's no leak in the loft. There's a short drop from the boiler, an elbow and then about 4ft of pipe that goes out. Everything is dry in the loft and condensate can be seen coming out of the end of the pipe onto the flashing. It's once it gets there that it's not running down the flashing and/or tiles as far as the guttering and is coming out of the woodwork instead.

Now that's a possibility I suppose.

Thanks Bob, good idea.

[harry]

Yes, the acidic condensate water affects concrete in a bad way. Could be the water is in fact running down the roofing felt underneath the tiles.

You need to get up there with a ladder and look closely at what's happening.

[Andrew Gabriel]

A roof will normally have the edge tiles lifted at the outer edge to prevent water running over the edge - yours doesn't do this. I can't see in the pictures, but the barge board doesn't seem to be set back far enough under the roof edge either. I suspect rain water also runs over that edge, i.e. the fault is nothing to do with the condensate drain, except that probably generates a more continuous flow than rainwater (and it's slightly corrosive, and running over the leadwork is not great). Another possibility is if one of the edge tiles is cracked.

Replacing the barge board with a plastic barge board is probably the easiest fix (note that's *replacing* and not overboarding). Changing the edge tile bedding would be more work.

If there's a soffit behind the barge board (can't tell from pics, but shadowing looks like there may be), then behind the board will be outrigger timbers supporting a verge rafter, to support the batten ends and the barge board.

[Munch]

Andrew Gabriel explained on 13/11/2016 :

Thanks very much Andrew. Plastic barge boards are on the list but it'll be next summer before we can afford that. The car needs new tyres all round before winter begins to bite :-(

[Jeff Layman]

Yes, but don't do what the installers did with my neighbour's condensate pipe. The idiots extended it almost to the bottom of the gutter. When it snowed, and that partially melted in the gutter and refroze, the bottom of the pipe was below the surface of the water and got blocked by ice. It didn't take long for the boiler to detect the blockage and turn itself off on one of the coldest days of the year!

[Andrew Gabriel]

I recall an incident here when domestic condensing boilers first appeared. Installer had the condensate dripping onto a conservatory roof, which was OK until winter, and a 4' icicle came crashing through the conservatory.

[tabbypurr]

Well, if you've got a soldering iron.... Oh, this is not India.

NT