Help needed. Stairs/Concrete/Damp

[Willsa]

Hi I've started a thread previously about my dry-rotting Victorian terrace. I'll update that one as I make progress in dealing with the rot. However, to make that progress I need help to unpick what is going on beneath the stairs.

Here goes:

The picture one is of the stairs unboxed and with the rot-affected treads removed.

The second picture is of the stairs from behind/below.

As you can see, the suspended floor is replaced with concrete that does not extend below the stairs... I think that's purely due to unwillingness remove lath/plaster from below for access!

 

[Willsa]

The resulting hole due to not extending the concrete floor is covered with:
Plastic sheeting
A slab of terrazzo
Rubble

The plastic sheet is wet underneath. So is the terrazzo slab. No wonder there's rot!

 

[Willsa]

It's a complete mess as the stair timbers are effectively hanging suspended in the air or on bits of moving rubble, so there's no structural support and the wood is prone to cracking.

 

[Willsa]

Questions:

1.What is the thin lead pipe running along rhe wall? It's cut and bent just inside the bottom step.

2.Why might be the underside of the plastic wet? Properly wet.

3.What would you do? Once the damp is dealt with - fill in with concrete? How to go about that? Unfortunately there is no way to dig out and replace.


I'm sure I can fill in some more details if needed...

Thank you in advance forum dwellers!

 

[malcolm]

Looks like a world of pain there. The underside of the plastic will be wet. That's the problem with waterproofing - anything on the other side of the waterproofing will be soaking wet because the water can't evaporate away. If you also waterproof the walls on both sides too the water will go up and up.

The ideal would be to have exterior ground levels around 6 inches lower than the plastic level and an absence of cement or paint on the outside so the floor can slowy dry out without shoving water up the walls. What are your outside ground levels and coverings? It looks like someone has put 6 inches of concrete over a previous floor covering.

The pipe looks too small to be lead and looks more like 1/2 inch copper. Could be the water supply.

 

[Willsa]

Looks like a world of pain there. The underside of the plastic will be wet. That's the problem with waterproofing - anything on the other side of the waterproofing will be soaking wet because the water can't evaporate away. If you also waterproof the walls on both sides too the water will go up and up.

The ideal would be to have exterior ground levels around 6 inches lower than the plastic level and an absence of cement or paint on the outside so the floor can slowy dry out without shoving water up the walls. What are your outside ground levels and coverings? It looks like someone has put 6 inches of concrete over a previous floor covering.

The pipe looks too small to be lead and looks more like 1/2 inch copper. Could be the water supply.

I'm glad to have company in working this out!

I've had your typical trades-people in and have gotten no further than "leave as is and rebuild the stairs" and "DPC injections". Ermmm... How's that going to stop the new steps from rotting?

Let's start slowly with the pipe.
Yep, that's copper - vintage enough for me to jump to lead conclusion!
Were water supply pipes that tiny?

The pipe feels cold and clammy. Could it still be connected somewhere? How to trace? One end is compressed shut next to the bottom step, the other side disappears under the concrete...
I wrapped a tissue around the compressed end to see if it gets wet overnight.

I'm not on the water meter so it's difficult to identify possible leaks.
I have been told (but trades have been wrong in every instance thus far so I'm not sure how much weight this holds) that the current water supply goes via the coal alley to the back of the house and into the kitchen.
How do I find out for sure? Ask the water company?
The rot and damp seems to follow the mid line of the house from the hall to the back. If there are buried leaky pipes, that might be the issue. But not sure if there are pipes!

 

[Cubist]

Hi Willsa,
In a domestic setting pipes, copper or lead, would be used to carry either water or gas and you can infer which of these from the points of origin and destination of any pipe you may come across. As this pipe has been buried for whatever reason its best to at first assume its a gas supply as this is the most dangerous. To make a more informed decision you can consider the likely points of origin and destination by considering the layout of the rooms and the orientation of the pipe you can see. Are there kitchens, bathrooms or toilets nearby? Do you know where the water supply stop-cock is and is the routing of pipe-work from it clear? Are there any gas appliances, stoves, fireplaces and in older properties any evidence of gas lighting? Be aware that sometimes copper pipe was used also to carry overflow water from a cistern from tanks in the loft or bathrooms added later in the buildings life.

With water pipes that are still in use you can also sometimes 'feel' the flow of water through a pipe by detecting movement and heat changes through your fingertips. Turning on the taps in the various rooms in sequence can help you to detect such.

Hope this helps.

Cheers,
Cubist

 

[Willsa]

After some more pipe investigations...
There was actual water on the pipe this morning. Just a couple of drops worth but exactly where the bottom step is and the base of the rotted away stringer!

I haven't been able to recreate the drops by running taps or anything, so I assume it's a tiny leak that takes time to accumulate the water. I'll check again in a few hours to make sure I'm not going mad!
Leaky pipe = sound mind

There is no sign of equally thin pipe/tubing anywhere.
However, there is no radiator in the hall but clear signs that there used to be one. The pipe might be a microbore for a radiator?
But there is no radiator and I have a combi boiler with standard copper, so...

If I find water again : plumber or heating engineer? Try both?

 

[Cubist]

If the pipe were part of a central heating system I would expect there to be two pipes; a feed from wherever the pump was/is situated and another direct or indirect - via another radiator - back to the pumping circuit. The outer diameter of micro-bore c/h pipes is approximately 10mm and standard about 15mm. The latter being the same for gas pipes. Don't be lulled into a false sense of security - the water you are seeing may very well be condensation forming on a cold metal pipe. Have you checked the routing of the gas supply into and through the house?

 

[Willsa]

If the pipe were part of a central heating system I would expect there to be two pipes; a feed from wherever the pump was/is situated and another direct or indirect - via another radiator - back to the pumping circuit. The outer diameter of micro-bore c/h pipes is approximately 10mm and standard about 15mm. The latter being the same for gas pipes. Don't be lulled into a false sense of security - the water you are seeing may very well be condensation forming on a cold metal pipe. Have you checked the routing of the gas supply into and through the house?

Thank you Cubist, you have confirmed it for me : I'll call in a pro to have a look.
However, that does mean my sanity goes unconfirmed due to variables

I have solid concrete all through the downstairs so I'm out of my comfort zone in identifying what goes where. And the fact that everything is a bodge, doesn't help if we are trying to deduct things via the regulations or common sense!

Just found a cable running around the dining room behind the skirting and nothing in common with the safe zones. That'll be my kitchen loop too then... Sigh

This house needs an x-ray to be safe to touch anything!

 

[Willsa]

On a positive note, I found 1875 half-penny whilst mucking around under the stairs. That's around the time the house was being built. It's kinda sweet. I need (much) more though!

 

[Cubist]

Happy to have been of some, albeit limited, help. You're right to discount the regulations and common sense as the inspiration and guidance used by others but, having said that, you can always rely on the fundamental laws to govern their behaviours. In particular; they will always follow the line(s) of least resistance, or rather, least work, and if theres a dumb way to do it they invariably will do it that way.

Believe me, your outlook will become just as jaded as you work your way through you home. Take care and keep us briefed.

 

[a twig]

When figuring these bodges out - I try and trace them back with WWALAD. “What would a lazy ar*e do”.

i.e. if you just wanted to “get it done” and didn’t care about regs etc, what would be the easiest way. It’s helped me in the past understand “interesting” solutions.

The most confusing I had was a pull switch in the loft above one bedroom that turned off half the upstairs lights. Turned out the sparky had been up in the loft and couldn’t be bothered to climb down and fetch a junction box when re-wiring, so had used the an pull switch he had found up there instead