Penetrating Damp from Guttering/Pipework

[Chuckles586]

The damp's recent. We bought the in August 2014 and had damp proofing put in two rooms, including this one. At the end of the room that I've shown here they injected the stuff that goes into the walls, but only up to just below the dado rail that you can see. There was no mention of damp being higher up than that and no treatment for anything above the rail.

We then painted over the paper that was already there and everything was fine until around September last year when we first started noticing the problem. It's spread a little since, starting at the top and moving downwards, but the progress is very slow. It doesn't really feel damp and there's certainly no mould that I can see. I've checked as much of the piping around the bathroom (above this spot) as I can, but there isn't much that I can get to without ripping stuff out. There's a vinyl floor in there too, so taking that up could ruin it.

I appreciate all the help and replies - any more advice would be brilliant.

 

[loply]

Those elbows on the outside of your building look like pushfit elbows to me, I would chisel them out and replace with solvent weld... To my mind it's not a good idea having a push fit elbow buried inside a wall... A solvent weld one will never leak but pushfit I would always question when it's not visible/accessible.

One thing you could do, if you can be bothered, is to get rid of that hopper all together. Put a thing called a "strap on boss" on the soil pipe and your other bathroom waste can go directly into there. I prefer it that way as hoppers inevitably lead to water splashing overboard when someone empties a bath or has a big shower. Even if that isn't causing your damp, it's not nice when you're standing outside and get a glob of soapy water on your head! Just have to do it right so that the pipe isn't protruding into your soil pipe to make a snag.

 

[Burnerman]

So the outside pipes that you have shown us are above dado height, obviously.....what's the pointing like on the wall between the pipes and ground level?
I just don't think the pipes are the culprit, that's all.....please give us some shots of the wall from further back?
John

 

[Chuckles586]

I'm out at work at the moment but I took this one when I did the others a few days ago. You can see the pointing on it pretty well and I didn't think it looked to bad.

Yes, the hopper on this photo is roughly level with the very top of the wall where the damp is appearing, which is what made me think it was causing the problem.

It does look like the pipes are pushfit to me. Maybe that is causing the problem.

 

[nebjamin]

Looks to me like the pointing is almost completely missing from behind the hopper. If this wall is SW facing and gets hit a lot by rain just normal rain water running down the walls could get in through there.

I had a similar problem in my house 2 winters ago when we had all that wet windy weather... wind blown rain hitting the wall going through cracks in the render and appearing as stain marks on the inside.

Might also be overflowing if you get heavy rain.

 

[Chuckles586]

I'm hoping it is just the pointing, and it looks like that needs doing even if it isn't the direct cause of the problem.

Also, if I take the hopper off what's the best way of screwing it back on? Rawl plugs back in the existing holes then screw into them or something else?

 

[nebjamin]

If it were me I'd just unscrew it from the wall, fix up the pointing and fill any deep holes in the bricks with mortar, swap out the push fits for solvent welds and put it all back with the fixings you already have (maybe use new screws). No need to drill new holes unless it has to go back in the same place. Presumably there are already rawlplugs in there. I would be surprised if that doesn't fix your problem.

 

[Chuckles586]

How do I go about swapping the pipes for solvent weld ones? Can I just pull out the visible part and attach a new one or will I have to pull out the horizontal section of piping that's in the wall and replace that too?

 

[nebjamin]

I think it depends on the size of the pipe. IIRC the push fit is a different diameter from the solvent weld. Measure the pipe and see if you can find solvent weld corners.

TBH if putting solvent weld on there involves you replacing the whole pipe run and pulling up floor inside I wouldn't bother. Just fix the pointing and see you how you go.

 

[Chuckles586]

I might just do the pointing and see how it goes then. Thanks for the help, everyone.