Paint bubbling and flaking off wall

Yorky

I noticed that a line about a cm thick has appeared on both sides of an internal wall. When touched this line is puffy and then flaky and powdery underneath. The wall hasn't cracked, just the paint is affected.

Does anyone know what may be causing this? The house is two years old.

metalscrubber

.

John Mason

this happened in my wonderful house but it was a damp problem. is it on outside wall? or are there any pipe running behind it ?

Yorky

This is an internal wall and the radiaor pipes are in the floor

I've taken some photos of the wall from both sides:

http://i238.photobucket.com/albums/f...n/P1020768.jpg
http://i238.photobucket.com/albums/f...n/P1020763.jpg
http://i238.photobucket.com/albums/f...n/P1020761.jpg

Any ideas what it might be?

10-10-20

Sorry - image page not found!

Yorky

Aplogies - here we are:


http://i238.photobucket.com/albums/f...n/P1020768.jpg
http://i238.photobucket.com/albums/f...n/P1020763.jpg
http://i238.photobucket.com/albums/f...n/P1020761.jpg

Kaldorn

can you actually use this site?

Yorky

I'll try again:

http://i238.photobucket.com/albums/ff250/Kilnadrain/P1020768.jpg
http://i238.photobucket.com/albums/ff250/Kilnadrain/P1020763.jpg
http://i238.photobucket.com/albums/ff250/Kilnadrain/P1020761.jpg

yop

bit odd that, downstairs is it?

Any flooding of late?

Is it a brick or block external wall?

Sounds like rising damp to be honest.

Is your lawn or footpaths higher than your damp course by any chance?

Can you get a pic from outside?

Yorky

Downstairs, no flooding,block wall, ground level lower than DPC.

I've had a very close look at the valves and one of them has a minute leak which is dripping onto the floor but this is not porous. As I say, the leak is so minute I can't see how this would be working its way under the floor and then up the wall.

The radiator in question was recently (last August) moved from another room as the original one was not providing sufficient heat output. It was too long for the existing pipe connections so one side was extended using an elbow,length of pipe and another elbow. There is some play in the pipe and, if there is leak, it may be at slab level where the elbow connection from the pipe running along the floor is fitted to bring the pipe up to meet the radiator. I fear that this elbow connection may have been disturbed and that is where the leak is. Is there any way of telling without ripping up the floor, including the concrete finished floor?

yop

That sounds like ur problem for sure, over time a little drip will build up for sure. Can u isolate the rad and turn off the water to it? see if the patch will dry up over time

Yorky

Unfortunately not as the suspected leak is below ground level.

Yorky

Thanks again for the replies. The plumber came back and fixed the drip on the valve which was so minute that there was only one drip on the floor after twenty four hours of wiping it. I just cannot see how the water was getting through the floor as the floor is laminated and it wasn't dripping onto a joint.

I suggested there may be a leak elsewhere, such as on the elbow joint within the finished floor, and asked for a pressure test and/or to tie up the ball-valve to see if the level drops over a few days but the system is pressurised so this is not possible. There is, however, a central heating pressure gauge in the airing cupboard and the plumber suggested aligning the red adjustable pin with the actual gauge pin to see if this changes over a couple of days - is this an accurate method of assessing whether there is a leak or not?

Assuming there is a leak, I asked the plumber what methods of leak detection are there and he said that the floor would have to be dug up. Surely some sort of non-invasive testing can be done first?

I've just checked it and it is now measuring 0.8 bar and the setting last Thursday was 1.2 bar - does this mean there is a leak?

Wertz

Yorky wrote: »

Downstairs, no flooding,block wall, ground level lower than DPC.

I've had a very close look at the valves and one of them has a minute leak which is dripping onto the floor but this is not porous. As I say, the leak is so minute I can't see how this would be working its way under the floor and then up the wall.

The water (assuming it's coming from this small drip) is unable to penetrate the laminate as you say, but IMO it is instead running back beneath the skirting, into the expansion gap of the floor and is being wicked by the skimcoat/plasterboard leading to the effloresence you're seeing in your paintwork. This leak may have happened a good while ago and has only recently shown a reaction in the wall as it takes a while for efflorescense to show.
I know little about plumbing but the only method I can think of to detect a leak without ripping up boards is to use a damp meter/tester on the wall to see if it's still actually damp, which it may not be.

Avns1s

Yorky wrote: »

I've just checked it and it is now measuring 0.8 bar and the setting last Thursday was 1.2 bar - does this mean there is a leak?

Not necessarily as the pressure varies with the temperature of the water in your central heating.

However, if you're comparing the pressure with the system cold i.e heating off for several hours and it was 1.2 bar and is now 0.8 bar, then you have a leak and I would suggest it's in the changed pipework under your floor.

Yorky

The pipework was not changed under the floor - it was extended above floor level to allow a longer radiator to be fitted.

Yorky

Update on this. The manifold is close to the affected area so I took the cover off it and there appears to be a leak coming from two of the motorized valves. I unscrewed the motor ( two screws) to reveal the spindle and mounting plate. There are two bolts securing the mounting plate to the metal body of the valve itself and these appeared to be tight but there is still a drip coming from underneath it.

Does anyone know why the motorized valve would be leaking in this area and how it can be rectified?

Yorky

I now have the same problem in an adjacent wall to the original leak. The paint is bubbling off the wall on both sides but this time there appears to be a mark at the top of the wall also. Could the mositure travel up to ceiling level?

I had a blocked shower drain recently and used a mini drain rod to clear it - could this have dislodged something? I've checked the shower and everything seems to be in order and the ceiling mark beneath it is not directly under the shower drain. Here are some photographs:

http://i238.photobucket.com/albums/ff250/Kilnadrain/P1040422.jpg (ceiling)
http://i238.photobucket.com/albums/ff250/Kilnadrain/P1040423.jpg (ceiling)
http://i238.photobucket.com/albums/ff250/Kilnadrain/P1040424.jpg (one side of wall)
http://i238.photobucket.com/albums/ff250/Kilnadrain/P1040425.jpg (other side of wall)
http://i238.photobucket.com/albums/ff250/Kilnadrain/P1040426.jpg

Is there a non-invasive leak detection test that can be carried out?

It seems strange that the affected wall is directly opposite the original wall which was affected by the previous leak in the manifold or perhaps that was not what was causing it at all?

There is a radiator on each side of the wall.

Any advice would be appreciated.

Yorky

Update:

I'm almost sure it is coming from a radiator(s) as the inlet valve on the central heating was turned off and the pressure dropped from 1 bar to 0.5 bar within two days. There are three possible radiators it could be emenating from - is there any non-invasive test that can be carried out to identify which one is leaking?

JamesM

Maybe I have this all wrong ?
The ceiling is damp - so I presume that the leak is from above this damp patch - but you are talking about downstairs rads !
Have you checked out the heating upstairs ?
From what you say there is a leak somewhere upstairs and it is flowing down the walls inside the dry lining.
If the heating system is loosing pressure - it is likely that the leak is from there.
Where are the motorised valves and did you get them replaced - the seals around the spindle often leak - although not in a 3 year old house.
Jim.

Yorky

Found the leak - it was both of the other motorised valves which had an intermittent drip which was travelling along the pipe lagging. That means all of the motorised valves have been replaced in a three year old house!

Does anyone know how to repaint a wall which has been affected by efflorescence ?

dny123456

I'm not a painter, but my builder recommended to me before, when painting a heavily stained ceiling. Before I did it, I was repainting over and over again, with the stains magically re-appearing a few days later.

First paint with a gloss paint mixed with white spirits, to seal the stain. Then paint over with normal paint. It did the trick.

Alternatively he said you could use a bonding mix (stuff they use to help plaster stick to walls)... but I just used the gloss paint.

Yorky

Have been advised to use zinsser bin primer (about €17 for a litre) which will seal the wall. Is it necessary to use this or would diluted PVA bonding suffice?

Juwwi

Yorky wrote: »

Have been advised to use zinsser bin primer (about €17 for a litre) which will seal the wall. Is it necessary to use this or would diluted PVA bonding suffice?

lm a painter and would recomend the zinsser bin primer.
l find that its about the best product on the market at the moment for covering up damp stains.