Rising damp?

[Helen Mari]

My mum has a midterrace Victorian with an external injected dpc around the side return.
There’s damp on some of the internal walls, like between the hall and what is now the kitchen (was the middle room).
The hall floor is solid? The kitchen floor’s awooden, but as there are fitted units there I can’t get at it. No water there just cupboards.
Maybe 15 years ago I gave it a couple of coats of damp seal and re wallpapered

 

[Helen Mari]

Sorry I hadn’t finished
Basically -
can you get rising damp on a freestanding internal wall?

 

[JohnD]

It's interesting to note that the damp has existed for quite some time and silicone injections did not cure it.

That is normal.

Post some photos please, inside and out. Include drains and downpipes. A house of that age usually (always) has drains that are cracked and leaking. Show the position and shape of the damp patches (flat, hilly, or mountain).

Walk round the house looking for the DPC. Mark it with chalk. It is pretty certain to be at the same height all round the house. Note any points where it has been covered up with paving, earth or render.

Find the outside stopcock (usually next to where the front gate used to be seen the house was built) and the inside stopcock (usually underneath where the sink used to be when the house was built). The supply pipe almost certainly runs in a straight line between them. It may well be leaking into the floor, often at the elbow where it turned up under the sink.

 

[Helen Mari]

Sorry, I’m not being clear, the damp is on internal walls nowhere near the dpc
Nothing to see unless I remove the skirting and wallpaper perhaps
I thought rising damp was on external walls or party walls

 

[Helen Mari]

Lots of photos but now I’m wondering if it’s the central heating pipes?
No idea how long they’re supposed to last?
Do they inject internal walls?
I know they’ll tell me that’s what she needs but I’m not sure she could cope with the disruption. Although if it’s the heating that’ll be worse.
If pics in order
123= outside and water main
4= lounge behind tv unit party wall
5+6=hall+kitchen behind
7+8=kitchen above sink +boxed in pipes behind
9= also hall under stairs party wall other side
10=dining room behind unit
Post other photos later as it won’t let me do more
I can’t thank you enough

 

[^woody^]

All walls built off foundations or a concrete floor should have a DPC, else rising damp may well happen.

However rising damp would only be at a height of around 900mm or so, and looking at some of the photos there is dampness at higher levels which would mean a different cause or problem

 

[JohnD]

in the picture with the thermometer, it looks like it is running from above, for example if there is a bathroom overhead with a plumbing leak. Or, if an addition, perhaps a roof or gutter leak. Was there formerly a water-heater above the tiles?

in the pic with the TV, is that corner damp, and is that a boxed-in pipe in the corner? What is above?

i can't make out other damp walls.

though it does look like the incoming water pipe will be under the hall floor. is that damp?

 

[mrrusty]

My opinion is the same as that of Heritage House https://www.heritage-house.org/damp-and-condensation/managing-damp-in-old-buildings.html and correlates with my own experiences in old houses. I don't believe rising damp exists. I believe that what we see is nearly always caused by condensation or penetrating/leaking damp. The latter should be fairly obvious to work out, the former less so. The problem as I see it is we like to live in nice warm draught free houses which means house air now potentially carries lots of water vapour. The bottoms of walls are the coldest area, not only because heat rises, but also because of the heat sink effect caused by the direct ground connection. The other contributing cause I believe of damp-looking patches, growths, crumbling plaster etc, is salt poisoning caused by combustion products from burning coal reacting with building materials. The salts created are highly hygroscopic - absorbing water vapour from the air. Condensation + salt = crystal growth/efflorescence and flaking paint/wallpaper crumbly plaster etc..

I know there are many different opinions, and this is my point of view.

 

[jeds]

Lots of really useful information on rising damp in this thread.

Rising damp does not exist | DIYnot Forums

Sorry, I meant useless.

 

[Helen Mari]

Apologies guys
I’ve been up a ladder with a paintbrush all day

mrrusty and jeds
I’ll read those later thank you

woody
I agree

JohnD
Sorry I’m so tired now but in brief
The thermometer is near the kitchen sink with a bedroom above There’s a bathroom next to that and there’ve been a few leaks (repaired now) but the damp predates that
Pic 11 boxed in piping behind
Builder today said not pipe work but I’m going to check water meter the way someone explained

Tv’s in lounge with bedroom above with fitted wardrobes- no smell- but who knows? There’s no boxed in pipe but wallpapers bubbling/detached same as under stairs and behind unit in dining room.

The hall floors the original ?tile? from maybe 1900. I think it’s got ply then underlay then carpet. I’m hoping to replace with engineered wood.

I’ll draw a plan tomorrow which should explain things better but I know the water mains the original so probably lead?

Please bear in mind my mums in her 90’s and I’m not so young now either so any really major upheaval will have to wait for the next owners in a few years time