Penetrating Damp from Guttering/Pipework

[Chuckles586]

I'm getting some penetrating damp on an interior wall. In pretty much exactly the same spot on the outside wall is this.

The top brown pipe comes down from the guttering around the roof and the others carry waste water from the bathroom - not sewage, just the stuff from the sink and bath.


Is it possible that this is overflowing? Some of the pointing behind it isn't in great shape either.

Should I replace it, or is there some other way of sealing off the wall?

All suggestions greatly received.

 

[Burnerman]

For sure, some of your pointing there is a bit moth eaten, but a couple of points to check.
Does water ever shoot out of the hopper head - when you pull the plug from the bath or wash hand basin?
Next, there doesn't seem to be much moss or other verdigris on the outside of the wall, and as the bathroom fittings are presumably just behind, are you satisfied there isn't any drain leakage anywhere?
John

 

[Chuckles586]

Thanks for the reply. Is there a definite way of checking for drain leakage?

As far as overflowing goes, I guess I could just turn all the taps on and see what happens.

I figured this might be a combination of overflowing and damaged pointing but I'm certainly no expert on what I'n looking at. Might this be a re-pointing job?

 

[Burnerman]

Check for overflowing by filling the basin / bath or whatever, then pull the plugs just to see what's what.
It's unlikely for plastic drains to leak in the wall ( unless there's a joint or coupling in there) so can you give us a pic of the damp, please?
Any cracks in the pointing is best attended to, obviously, but it doesn't seem too bad from what we can see.
John

 

[Chuckles586]

It looks a bit worse than it is here 'cause of the flash, but it's appearing between the join in the wallpaper. It looks like it's then running down to just below the dado rail.

There's a damp course fitted into the wall that comes up to just below the dado rail, roughly where the damp ends.

 

[Burnerman]

Check the outside for overflowing.....obviously if there is rain water there too, the hopper has lots to cope with.
How about the bottom of the down comer .....is water running free there, and not backing up the pipe?
John

 

[Chuckles586]

There's no problem with anything backing up in the pipes that I can see. I'll have to check for overflowing but I guess that's a possibility.

If that is the case, is it best to take it off, re-point and put it back on?

 

[Burnerman]

Water penetration to that extent should surely come from an overflow, I'd guess......see what happens, and if you need to remove the hopper head and downcomer to repoint.
If you suspect porous brickwork or pointing, solutions such as Waterseal may have an effect - but they only soak into the solid wall and repel from there as they don't fill any gaps.
John

 

[theprinceofdarkness]

I would say the hopper is OK as there is no "tide" mark of soap or muck around its rim. I reckon that the area was needs cleaning up and all the pointing redone, especially behind the hopper. It could help if you put a thick bead of silicone along the top of the hopper to stop water getting in behind it. Also you should stick a black bag in the hopper over the top of the pipe entries to stop leaves getting in and blocking it.
Frank

 

[Nige F]

Water penetration to that extent should surely come from an overflow,
John

Indeed - that overflow pipe leaning back toward the wall - like they do

 

[Chuckles586]

If that pipe has come loose what's the best way of fixing it? Chiseling it out and replacing it?

 

[Burnerman]

If there's any visible fault, it could be behind that black elbow as I think I can see some moss at the back.....has the hopper head been cut there?
John

 

[Doggit]

Strangely, the inside looks damper than the outside. It's unlikely that there's a crack in one of the outlet pipes in the wall, but it's possible that there's a leak from the water services in the room above that's tracking down the pipe to the wall. But you'd need to life the boards to check this. The other question is how well ventilated the room in question is. If the rooms closed up, then you're getting internal damp problems rather than external ones.

 

[Chuckles586]

Thanks for the replies - what does it mean to "life the boards"?

The room was getting rising damp around the bottom, so we had damp proofing put in when we bought the house (August '14).

 

[Burnerman]

Doggit means to 'lift' the boards.
Just looking at this again, I don't think this problem is coming from where you say......is the damp historic - i.e just stained - or is it recent?
Does it actually feel damp and encourage mould, or is the wall just cold?
John