Condensation, or water leak?

[A.Lee]

I had to visit a house today, as they had a water leak. Or rather, their downstairs toilet keeps getting wet.

I had a quick look, expecting to find a dripping pipe, but couldnt see any fault on the visible pipework. The water is all over the toilet walls/ceiling downstairs, and has been there for a while, as there is mushroom like growth on the ceiling. Directly above is the upstairs toilet and sink. There were maybe 20 droplets in one corner of the room, and the rest of the room looked like someone had just had a shower in it. The outside wall is also wet from just below window height. Unfortunately, upstairs is covered in laminate, so I couldnt take up the flooring to see if one of the pipes is leaking from between the floor onto the ceiling below.

I had a poke at the plaster ceiling, but it all seemed quite solid. At the rear of the downstairs toilet is an unheated small room (3' sq.), which has a slight dampness at the ceiling, but is otherwise dry.

My main thought was there must be a dripping pipe under the upstairs floor.Though the ceiling doesnt look like it has had water running through it.

My query- Has anyone come across such a bad damp problem that has been caused by condensation? Am I missing something? Thanks Alan.

[Phil L]

You are missing a leak.

Where can the water be condensing from for it to be condensation? - the ceiling fungus alone is an obvious sign of water penetration....if the bog isn't very big, it may be easier and cheaper to pull down the cieling in there and replace that rather than mangle a good floor upstairs. This is a good advert for not having upstairs bathroom floors tiled / laminated etc.

[A.Lee]

Well, yes, I was going to pull down the ceiling to have a look, but I need the owners go-ahead before I can do that. I was pretty sure it was a leak, but had no way of finding out, as any leak would be in the floor/ceiling void. I do agree with you about the flooring - I wont be putting any more laminate down in my house - I found out the hard way, needed a new TV aerial plug in the bedroom, and of course, the cable runs in the void, so no access to get at it under the laminate. Alan.

[Phil L]

Just tell them that you think there is a leak there as all signs point towards that, and in any case, the fungus ceiling needs replacing anyway. It obviously cannot stay as it is and something needs to be done, I assume they've tried various heat / ventilation methods?

[BRG]

Alan,

As I have obviously not seen the job, I am going to ask some possibly silly questions to try and get an idea of the situation - they are not in any particular order and they may help you elaborate on the situation.

How old is the property?

Where are the soil stack runs?

What is the outside wall made of - brick, stone, cavity, solid - or is it a prefabricated type of construction?

You say the "plaster" ceiling is solid, would that be plasterboard or lath and plaster - or possibly even the old asbestos cement type of board.

Is the ceiling wet and crumbly on the edges against the outside wall?

You say that the walls are wet on the inside, is that wall facing into the prevailing wet weather direction and is it wet only in one place or from ceiling level down to the floor?

Is that particular room well heated or well ventilated with vents through walls?

The reasons for the questions:

If there was a pipe leak above the ceiling, the plaster ceiling would feel very soft and probably bulging and if there is a light fitting nearby, water would possibly run down through that - unless the ceiling is of the asbestos cement type board.

If the ceiling is crumbly only on the edge, it may indicate damp penetration through a solid or through a blocked cavity wall.

If it's a cavity wall, and the soil stack is of asbestos cement or cast iron (even plastic) there could be a leak where it passes through the wall and dropping into the cavity onto the window lintel and soaking through the internal skin - ditto if it's solid or stone but then the water would tend to 'soak' down - possibly following cracks in the compo or black mortar jointing.

A number of possible suggestions that may be near or very far away, but I hope they will help.

BRG

[A.Lee]

1940's, directly where the leaks are, though the mains pipes also run along that wall.

Double brick with cavity

I think it is pasterboard, though am not sure.

Not particularly - I stuck a screwdriver into it, expecting it to go through, but it was quite solid.

No, only wet on the bottom corner,up around 3 feet, right where the soil stack enters the ground.

No heat, but they say they keep the small window open regularly.

It is cast iron, and I also suspected it was leaking in the cavity, as the wall where it enters the ground is thoroughly soaked. I've just sent off an email to the owner (in California), to see how they want me to proceed, i told them I cannot do a thing until I have pulled down the ceiling to inspect the pipework. Thanks for the thoughts. Alan.

[BRG]

Problems like that are a bitch to identify Allan and the best of luck to you.

BRG

[cj]

Hi Just to add another track to take ,whilst I think BRG is on the right track I recal a similar thing in a terraced house with 3 layers of 'Lino' on the bathroom floor .Turns out the family had 3 active kids who were bathed most nights and mum used a jug to wash them ,when she left them alone water fights started and the water ran to the edge of the flooring and ran through the edges of the room running down the walls of the toilet below also finding its way into the cavity by way of the exiting pipework AND electrical cables.( Yes it was wired in the cavity common then )

HTH CJ

[Dave Liquorice]

I've certainly seen walls running with condensation but that is normally under extreme provocation like in a bathroom after a shower or bath or close by but it normally doesn't last long on the walls. Another good form of provocation is the venting of a tumble drier into the space rather than outside.

[The Medway Handyman]

The OP refered to it as a 'donstairs toilet'. I assumed it didn't have a bath or shower?

[mogga]

Did you take some pictures of it?

[mail]

Fungus = ceiling needs replacing in not necessarily the case

I suggest for and INITIAL view you use an endoscope or small hole torch and mirror Small hole(s) can be done with, say, 2" hole cutter (keep the plug if poss) Identify source and fix it with or (possibly) without) removal IF fungus is Pezziza or similar plaster fungus (as is likely) then plaster removal can be limited to what is necessary to fix leak and dry out structure Of course it may be simplest to knock down the lot but without seeing.... difficult to say Chris

[A.Lee]

No, I should have done, as the fungus growth was quite spectacular - a bit like a lump of 6 inch by 1 inch evostick. If I get called back there, i'll do the pics first. Alan.