HELP: Patches on plaster - Damp?! :(

Newuser0

Hi guys,

I have a problem with a wall in my house at the moment which is driving me mad.

I had bought my first house 5 months ago and had it skimmed approx 4 months ago. The whole house has dried up apart from one wall which has a few weird patches on it. I had noticed these patches after a couple of weeks of it being skimmed and from my knowledge they have not changed.

Before plastering, when I had taken off the wallpaper, the offending wall plaster looked quite dark and was coming off by tapping it. The previous owners had a fitted wardrobe against this wall so I couldn’t see it when viewing the house. Not knowing much about plaster, I didn’t think much of it and the plasterer didn’t mention anything either so I didn’t see the old crumbling plaster as a problem.

A little more detail of the wall: 

1. external wall 

2. The wall is in the master bedroom. 

This is situated on the first floor above the front room which has a working gas fireplace in it albeit quite an old one. Above the bedroom is loft space.

3. There was more than likely a fireplace on the wall in the past

4. chimney right behind the wall

5. The bedroom beside it which more than likely also had a fireplace in the past has no problem on it.

My question is, what could be causing this problem ? Is it a leaking chimney? Does the plaster need to be taken back to brick? 

I had a roofer round who is saying the chimney flaunting would need to be redone and that would resolve the issue, but I don’t want to be paying out if the issue has nothing to do with the chimney.

Any help would be very helpful. I’ll also attach some pics 

thanks in advance !

Newuser0

Pics attached .

the room is situated beneath the first chimney stack (the one closest in the pic)

Doozergirl

It's almost certainly something to do with the chimney, but have you checked the gutter during rain to be sure that they aren't leaking in any way?  

There should be some ventilation of the chimney into the room as a start.  Vents can be ugly, so maintaining a fireplace opening is usually my choice.  

Up top, you're really going to have to trust a roofer.  What the one you spoke to was referring to is called flaunching, not flaunting ☺️. It's the mortar that holds the pots in place.  If there is a problem with it, a photograph will show it, much like any other roofing problem.  It's not hard for a roofer to photograph what they think the issue is.  Have they actually been up?  

What is the flashing made from?  Is it lead or is it cheap flashband?  Also I can't make out what is happening at the back gutter.  Is there vegetation springing out of it?  Maybe the capping could be better.  There are better options available than the rudimentary capping.  

There is a slipped tile up there too, by the look of it. 

Have you checked in the loft as well? 

Martin_the_Unjust

Doozergirl said:

It's almost certainly something to do with the chimney, but have you checked the gutter during rain to be sure that they aren't leaking in any way?  

There should be some ventilation of the chimney into the room as a start.  

Yep, fit a rain guard at the top and a vent at the bottom and it should, in time, sort out your damp patches.

Newuser0

Doozergirl said:

It's almost certainly something to do with the chimney, but have you checked the gutter during rain to be sure that they aren't leaking in any way?  

There should be some ventilation of the chimney into the room as a start.  Vents can be ugly, so maintaining a fireplace opening is usually my choice.  

Up top, you're really going to have to trust a roofer.  What the one you spoke to was referring to is called flaunching, not flaunting ☺️. It's the mortar that holds the pots in place.  If there is a problem with it, a photograph will show it, much like any other roofing problem.  It's not hard for a roofer to photograph what they think the issue is.  Have they actually been up?  

What is the flashing made from?  Is it lead or is it cheap flashband?  Also I can't make out what is happening at the back gutter.  Is there vegetation springing out of it?  Maybe the capping could be better.  There are better options available than the rudimentary capping.  

There is a slipped tile up there too, by the look of it. 

Have you checked in the loft as well? 

 Thank you for replying doozergirl!

sorry yes flaunching, stupid auto correct!

ive not looked at the guttering during rain but I will ask the roofer to have a look for me. The roofer who came yesterday didn’t go up, hopefully the couple coming today do go up. If so I’ll get them to take pics for me.

in terms of ventilation, do you mean I should put a vent internally where the fireplace would have been in the past? 

I have no problem with doing this as that wall will be covered by wardrobes in future. The fireplace in the room below is still working and I will be keeping it too.

the first roofer said the flashing is fine, but the weed growing around it he’ll clean up and if any problems sort it as well as the broken tiles. 

I’ve not been to check the loft, should I go in and check for water ingress?

Newuser0

Martin_the_Unjust said:

Doozergirl said:

It's almost certainly something to do with the chimney, but have you checked the gutter during rain to be sure that they aren't leaking in any way?  

There should be some ventilation of the chimney into the room as a start.  

Yep, fit a rain guard at the top and a vent at the bottom and it should, in time, sort out your damp patches.

The roofer said he would change the pot which has a sort of hat on it (lol) to a better one. Are you also referring to a vent in the room where the fireplace would have been? 

Martin_the_Unjust

Newuser0 said:

Martin_the_Unjust said:

Doozergirl said:

It's almost certainly something to do with the chimney, but have you checked the gutter during rain to be sure that they aren't leaking in any way?  

There should be some ventilation of the chimney into the room as a start.  

Yep, fit a rain guard at the top and a vent at the bottom and it should, in time, sort out your damp patches.

The roofer said he would change the pot which has a sort of hat on it (lol) to a better one. Are you also referring to a vent in the room where the fireplace would have been? 

I was but only only if the fireplace that was in the room fed a different flue to the one that's still being used below.

Newuser0

Ahh okay, if the flue is the same, how would I vent it then? Would it be a better if putting an external air brick?

stuart45

Fires have separate flues.

Newuser0

I had another roofer pop down not long ago, he’s of the opinion it’s the flashing and not flaunching.

As stated by doozergirl he’s pointed out the flashing is flashband so that would need changing.

he also said he doesn’t need to go up to the roof as he knows for sure that’s the issue.

i now have two roofers saying two different things lol 

one roofer was of the opinion it’s flaunching as the wall has dark patches towards the middle and it would have been the flashing if the edges had the patches.

and another saying it’s 100% the flashing is bad.

they both however said the chimney has enough ventilation as it’s not closed at the top so no need for ventilation in the room  

stuart45

You can also get hygroscopic salts coming through into the plaster from flues, which attract condensation.