Help WTF is this?

[LoveGigi]

This is the state of my bricks immediately behind my front door in the void under my floor boards. Recently my pine floor boards have been sweating over night and we have slugs. The problem has spread to my living room too which is not too far from this wall. There is clearly an issue possibly coming from beneath ground level below my front door step. What are the next steps I should take and is it worth speaking to my insurance company?

Could be minerals leaching out of the bricks due to water ingress.

You need the view of @PigletJohn !

Does it have a mushroomy smell? Could it be dry rot?

Do you have airbricks? Has anyone blocked/covered them up ? Is there an outside drain near by that is leaking or blocked?

Another vote for dry rot

Thanks for your replies, I don’t think it has a mushroomy smell. Re the air bricks, the other side of this wall is underground level. It could be a leak from the drain that takes the roof surface water to the sewer perhaps. Who do I need to speak to? I spoke to the insurance company they said I need a water leak tracing company to diagnose problem first? Does this sound right. Apparently the trace access on my insurance isn’t for this type of issue.

show usd what's on the other side of the wall.

very often it is a leaking pipe or drain

draw a sketch plan, please.

Include the outside stopcock (usually next to where the front gate used ro be when the house was built), the indoor stopcock (usuallu underneath where the kitchen sink used to be when the house was built); the route of the pipe between then (pretty always a straight line); and the gutter downpipes, kitchen and bathroom drains, manhole covers and, especially, the brown glazed clay gullies set into the ground beside the house.

(as it is getting worse, and is next to the front doorstep, it's quite likely a leak in the incoming water service pipe. How old is the house, and do you have a water meter, and someone in the house with sharp hearing?)

Hi PigletJohn, thanks for your message. I’ll do the drawing and post a pic of it soon. I really appreciate your help. Thanks

Hi again PigletJohn,

Here is my sketch. The exterior stop cock is about 1.5 meters from the building exterior, the lead water pipe runs straight from this and enters into my Livingroom void before moving through to the downstairs toilet (which used to be part of the kitchen) the stop cock is under the toilet floor and it converts to copper from there.

The downpipe from the roof sits directly between my front door and the neighbours front door. Which is about 1meter from the wall with the problem. My house is a Victorian terrace built in 1890. I’m second from the end of the row. There are no visible man holes

There is the mould substance on all walls beneath the hall floor and some on the livingroom wall on the same wall as the hall wall. The most mould though is on the wall that the door sits on.

Thinking about it, we’ve had a lot of rain over the past month or so which would mean more surface water which suggests that it will be my drain that is the issue. Possibly.

Do I need a drain surveyor with camera?

Thanks

Lg

well, if you can see the incoming water service pipe, and it doesn't seem to be leaking (even in the garden outside) then you probably have the very common broken brown-glazed clay gulley.

Can you take some more photos into it.

Commonly, an old one will have had new concrete built up round it, because the leak washes away the soil beneath, and the original concrete cracks and sags into the void. The gully itself may have tilted and sunk. Any ground around it will be surprisingly wet and muddy, and the concrete may sound hollow when banged (due to the void below). The new concrete often bridges the dpc. See if you can find one.

If it is just rainwater you won't have wild tomato plants and red worms, but you may have slugs. nearby trees and bushes may be unusually lush, green and fast-growing.

If your house is close to the road you might not have a manhole, or it might have been buried or paved over.

If you put a gloved hand into the gulley you might feel a crack, but it may well be on the other side of the bend. The water level in the trap may be lower than it should.

As all the drains in your road are likely to be the same age, other similar houses may already have had theirs done. Look for a modern plastic downpipe and gulley, and concrete or paving that looks new, and may be at a different height to yours. Perhaps you can engage neighbours in conversation.

BTW, even if the leak is not from the waterpipe, ask your water company to test the drinking water for lead content. There might be a subsidy, or free reconnection, when the time comes that you replace the lead pipe with a larger plastic one. It may be a good time when you are digging up the drain.

Have you got a water meter or a person with sharp hearing?

Cameras are usually poked up the drain from a manhole, but I expect they could wangle one down the gulley. You may have an (iron) manhole in the road, but prod round your garden. if you look in neighbours gardens you may see where it is usually put.

Don't allow anybody who sells silicone injections near your house.

btw I think the "mould" is likely to be gritty mineral salts, mostly limescale. Scrape a bit off and drop it in an eggcup of vinegar. It may fizz. look up "efflorescence."

If it is fungal you can heat it and it will dry out and shrivel up.

Prod the joists with a flat-ended screwdriver (nothing round or pointed) to check for rot. The joist ends might be on brickwork with an isolating piece of slate, or they might be built into the exterior walls.

p.s.

interesting to see that your porch has wainscoting. This is often applied to hide damp. So maybe parts of the wall have been wet for a long time. There ought to be an airbrick or iron grille under the doorstep. If the concrete "step" was poured after the house was built, it may have blocked the original ventilation.

I found a pic of an old glazed clay gulley. They are usually dark brown like an old teapot, but sometimes orange like a flowerpot.

the water level should be up to the bottom of the curve, which forms part of the trap. But the trap is usually broken, so water will drain out at whatever height the break occurs.

Mud, sediment and stones fall to the bottom of the pot so you can spoon them out.

IME they are always broken, but I've been told there is an old house somewhere in the country without a broken gulley. I have never seen this house, and don't know where it is.

did I mention the fern?

only grows where the soil is constantly wet and the air is humid.

I see the neighbours have recently raised the paving even higher, doubtless bridging the dpc (even more). They will be sad when it has to be broken out to dig up the drain.

Piglet John is fabulous! Just had to say that!

@Chunkymenrock

Piglet John is fabulous! Just had to say that!

That's exactly what I was thinking Also, LoveGigi's diagram is ace. Sorry, nothing useful to add.

couple of pics from someone with a similar problem from a different website. The poor fool though he only had to mend the top, but by page 2 he realised it all needed digging up.

Seriously, it is very common.

Wow tonnes of amazing info there PIgletJohn thank you so much! I’ll have a good second read in the morning and have a rummage in the gully! I may have to come back to you with more pics! I’ll also be conducting the experiments armed with some vinegar and a hairdryer! What this space! ;-)

Watch! Not what!

@PigletJohn

couple of pics from someone with a similar problem from a different website. The poor fool though he only had to mend the top, but by page 2 he realised it all needed digging up.

Seriously, it is very common.

@PigletJohn you are amazing. You're like having a very knowledgable dad on hand (in fact, maybe you are my dad?!).

I would love you know what your background is (are / were you in a trade, or just a competent DIY'er?

Does anyone in your real world know of your cult status on Mumsnet, or do you keep it very hush hush (like Banksy).

I would love you know what your background is (are / were you in a trade, or just a competent DIY'er?

PJ likes to remain a mystery about his persona, Isobel - many people have asked. I'm guessing he's a prof, not a DIY-er.

*retain

I found it a mistake to divulge my name when my Ladies Relaxation service in Hull was mentioned.

I'm only coming on to say that even before piglet John mentioned the fern I was going to point it out because he had mentioned their relevance on an earlier thread this week and even though I have absolutely no problems with damp courses I always absorb a piglet John tip [girlie swot]!

And to compliment OP on her excellent diagram and for knowing where her stop cocks are. Am utterly clueless on that front...