Black paint on the bricks

[tomwys]

OP,
The blackstuff was traditionally applied as a hopeful barrier to prevent further damp after damp had already appeared inside the house.
It was not "applied to hide damp".
There are no indications in your pics of: "a drain fault".

1. Can you indicate on one of the above pics where your solid floor level is?
2. Was the solid floor concrete laid on a membrane,(a DPM)? Removing a piece of skirting might show plastic?
2. Can you post a pic showing the interior damp?
3. Does the down pipe go into a gulley?
4. Do the bottom courses of painted brick project a little from the brickwork above them? Creating a lip?
Whatever, render should typically end with a Bell Cast.
5. If, for some reason, you want to test your drainage then there are various very simple very cheap, methods of doing it.

1. I marked floor level on the photos
2. I havent checked yet, will comeback about this one
2. Attached
3. Yes, there is definely a gulley and as mentioned earlier the water flows smoothly during rain.
4. The bottom courses are almost flush with the render, so without render the would be a lip. No sings of Bell Cast or anyting like that. See the photos

Re 5. What would you recommend, that can by done by a DYIer

These photos are from the front of the house. Previous ones are from the side, where you can see the paving is two courses higher

 

[ree]

OP,
Thanks for the new pics.
Given the solid floor(?) & the solid wall & the high ground level, and no signs of a DPC then maybe the best you can do would be the following:
As above, grind out the beds & perps to 25mm depth, & point up with 3:1 sand & NH lime mortar.
Inside, remove the skirtings & lift the floor boards, & then hack off damp plaster to a 1m height or up to the window board height.
Then post pics of the work so far.

Examine removed skirtings & floor boards for wet rot?
To later make good to the walls use the same above mortar mix for a lime render & a Limelite skim finish.
The floor boards appear to be fixed to joists but you say its a solid floor? Maybe its battens in concrete?

The render wont cure anything but it will give you 25 to 30 yrs free from damp signs on the wall surface.

 

[JohnD]

It was pouring last few days, so I did go out to check the drain, it wasn't overflowing, water was going smoothly down, the gutter above was fine too.

The soil around though, is very wet and more like clay than soil.

It is very common for an old clay gulley or pipe to be cracked or broken and leaking in the ground. The soil and the adjacent wall will have long term wet. If lime mortar is in the wall, it may be softened or washed away, especially below ground level. If there is an old adjacent solid floor it will usually be damp. The paving or soil around may have cracked or subsided, and the gulley may have sunk or show signs of earlier futile attempts at repair such as mortar benching or added concrete surround. Often burrowing into to the nearby ground will reveal wet or hollow cavities. Sections of wall that are not near a drain may be noticeably drier.

 

[tomwys]

I dag around the corner yesterday, down to the footings. Under the last course of bricks there is only chalk, no foundation.

The gully is cracked but only a the top, rest (as much as I can see with cheap endoscope) looks and seems solid. Precious owner mitigated the crack but using piece of gutter.

I'll dig more today and tomorrow, and then re point. Got 5 NHL Lime mortar.

I'm not sure what to do with the trench afterwards. What to fill it with, how hight etc.


Regarding the floor
There is a bit of confusion. Survey says left side of the house is solid, that's where kitchen, wc and landing are. I checked and that is definitely the case. Kitchen and wc have concrete floor, landing is made out of bricks.

Now, the right side of the house, Survey says it's suspended floors. There are two rooms on this side. The front one (the one with damp wall) and the back one both with floorboards.
I Lifted couple of floorboards in the back room and there is kind of concrete there but it crumbles very easily. Haven't lifted any boards in front room, so I can't tell what's below. Will do it next week. But floors in both rooms feel really solid, have do bounce. But again will report more when get a chance to pull out more boards.

 

[JohnD]

How old is the house?

If lime mortar was used below ground level, the joints might now just be packed with dust and mud. Squirt them with a hose and see if it washes out. This is typical of a long-term leak.

IMO it's better to repair old underground brickwork with cement mortar. Underground masonry is not exposed to the air so there is no question of it "breathing" to dry out. Cement hardens best in damp conditions, and is undamaged by water. Lime is the opposite.

You can pack in quite a stiff mix because it will absorb water from the wet bricks. An ordinary mix can go sloppy and runny in a wet wall. Wash out all the perished mortar first. Clean and refill in in patches to reduce the risk of loose brick slippage. Above the DPC you can use lime mortar to match original because it ought to stay fairly dry.

You can cut out the damaged gulley and replace with plastic. Broken gullies and clay pipes are very common on old houses. When you scrape away the surrounding soil you will find out if there are other breaks. It's usually at bends and joints. If the gulley has been leaking from the top, the water running down can wash away the soil supporting the pipe and gulley causing it to subside and break the pipe. If yours is standing on chalk it may be OK. Look out for water escaping during and after heavy rain or having a bath.

You can fill in round drains with shingle which is free draining and allows a little movement without causing a break. No large stones or bricks that might press on it and cause a break. It will settle a bit after filling in. The plastic is much lighter so does not stress the joints and pipes.

Finished level of ground or paving should be 2 bricks below DPC. More is better than less.

 

[tomwys]

@JohnD
Would be able to tell me where is the DPC. I'm poking aprund and can't find anything in between the courses.
Only that the third row from the top has been laid in different pattern.
And the biggest joint between 4th and 5th course is just mortar

 

[ree]

OP,
Forget about any possible DPC - simply crack on with grinding out & pointing.
The course of headers that you refer to were probably laid to act as bonding in a 9" wall.
Your interior floor material could be the main culprit for the interior damp signs?

My post #17 shows you a way to proceed, and you will now have to make a decision about : "Do you dig out the existing floors, & replace with correctly installed concrete floors or leave them alone?
Another alternative would be to leave the floors alone, & spread a plastic membrane across the surface with the edges lapped up the walls - with the finished flooring material laid on top. Not a favourite method.

 

[Ivor Windybottom]

The height of the damp shown inside suggests there's something severe going on. It's unlikely to result just from normal groundwater.

There must be an issue with the drains, downpipes, gutters, outdoor paving or indoor plumbing. Look upwards, the water may be coming from up above, running down and collecting at the bottom. Gravity does that!

I have a damp room. But I know the cause, it's an old corroded green 1950s copper water supply pipe that's gone totally porous embedded in the concrete floor weeping away into the slab. It took me 5 years to find, as it's behind the bath. But I know it's there and it will be eliminated within the next couple of years.

I'd stand back and have a thorough look at everything, rather than messing about with waterproof plaster and other botched cover-up jobs.

I doubt that some random bedsit expert on the internet is going to work it out for you.

It would be interesting to see what happens within that hole you've dug the next time it rains. If it fills with water then that could give a clue.

If you have a water meter then take a photo of it before you next go out for the day. Take another photo when you get back and compare. If it's moved, there's a leak somewhere.

 

[JohnD]

Would be able to tell me where is the DPC. I'm poking around and can't find anything in between the courses.

It is most likely two bricks or more above where ground level or paving used to be when the house was built. Sometimes you can see it under or beside a doorstep, or immediately over or under an airbrick to a subfloor void.

It might possibly be at the bottom of the render. Render is not supposed to be applied where it bridges the DPC.

Once you have found it, it will be at the same height all round the house, unless perhaps you are built on quite a steep hill. So have a look at the front and sides.

Gullies and drains would originally have been at ground level, which gives a clue.

Sometimes you can see it if you look at the inside of a wall, under the floor.

 

[JohnD]

You showed a picture of a wet-looking floorboard next to a radiator, where there seems to be rubble beneath the floorboard.

Rather than this being a concrete floor, I suspect it is where a builder has swept or shovelled his rubble under the floor to hide it and save him the effort of disposing of it.

This is very common, especially when an old fireplace is removed or bricked up. It is very bad practice.

Clean out the void and see what you find.

Damp patches next to radiators and their pipes are often caused by plumbing leaks.

 

[Ivor Windybottom]

This...

...looks too wet and too high to just be rising damp. Not impossible, but I'd be looking for bigger issues to be causing that scale of problem. It's barely inhabitable, you'd get in legal trouble if you rented it out.

It's unlikely to be the result of it rising from soil that's anything other than utterly saturated with water.

There's likely to be something going on. Better to actually fix it than muck about with cosmetics, waterproof or breathable plaster etc.

Dig some holes outside, get the floor up, find out what's going on. I doubt it's just a characteristic of the building.

 

[foxhole]

Appears the render is a second coat over original which was applied crudely up to down pipe and not behind leaving gaps for rain to penetrate but not escape .

 

[JohnD]

The gully is cracked but only a the top,

Looking at that picture, I think the gulley is missing, and all that remains is the broken socket it used to fit in. The original gulley probably incorporated a trap, and would have been about 16" high. Do you think that matches where the original ground level used to be?

Is the wet internal corner close to the broken drain?

The wet patches on the internal walls are mountain-shaped, and the source of water is likely to be close to the highest point of the mountain.

 

[Ivor Windybottom]

Appears the render is a second coat over original which was applied crudely up to down pipe and not behind leaving gaps for rain to penetrate but not escape .

Based upon what evidence do you spout this nonsense with such great certainty?

It's wet, very wet. Something is making it wet. Beyond that it requires investigation to find out why it's so wet. I think that's about all we can get from the photos.

 

[Ivor Windybottom]

If that drain (or the remants of) are connected to a soakaway then it may work initially, until it gets full, then it overflows. You need to wait until it next rains very heavily and for a prolonged period to check.

Soakaways can even turn backwards - take in water from the surrounding soil and deliver it to the house. Very possible with yours, as it's open below ground level.

Definitely don't fill that hole in, and keep a close eye on it over the next few weeks.

And don't listen to anyone spouting nonsense with great certainty!