Damp/Condensation Bottom corner of room

[d4rkcell]

Hello, I hope this is the right place to post?

Recently we have decorated our front room. This basically involved us removing radiators and having the chimney breast re-plastered. The weather was really really cold (around 3 celsius). So the room got really really cold and that may have caused the problem I am having?

When we finally got to painting the room we noticed that the paint in some of the corners near the floor wasn't drying. We never had this problem a few years back when we painted. Anyhow I got a small heater and pointed it in the direction of the wet paint and it dried... ish. The paint is now dry but there seems to be a damp/condensation dark mark on the wall that gets worse when we cook etc. I am assuming this is condensation hitting the cold wall. This was never a problem before we decorated the room so I am curious if anyone might have an idea of why it may now be a problem? We have had no rain at all so doubt its rising damp.

We did have cavity wall insulation put in about 12 months ago and I have only recently noticed that one of the holes the cavity wall guys drilled was missed when they were filled in. This hole is on the outside wall which is suffering from the damp/condensation patch in one corner, could this be the cause? e.g. cold air in cavity causing inside wall to be cooler than expected resulting in condensation forming?

I have tried leaving windows on the night latch and this seems to help the issue but it worsens and gets better but never completely disappears in this one corner. It isn't wet to touch its just a dark patch. Thankfully it is behind some furniture but I can't help looking to see if it is getting worse etc. I intend to fill the hole on the outside wall when the weather picks up here.

Any advice would be welcome, the room has never had this problem until we decorated. It has one Air Brick/vent in the room that does appear to be venting a very light breeze into the room. Anyone got any ideas?

TIA
d4rkcell

 

[d4rkcell]

I hope this isn't construed as being rude...

bump

 

[jeds]

Certainly condensation. Bottom corners is the classic area due to being the coldest spot and lack of air movment in the corners. Lack of insulation would make that worse and my guess is the insulation has not been properly installed around the corner. If I were you I would check that and invite the installer to make good if not. And also make good the hole afterwards.

 

[dann09]

I agree with jeds ref condensation.

The hole you refer to, it's probably only 20 to 30mm( irrelevant) - a little plug of sand and cement will fill it.

The only foolproof way to determine the coverage of cavity insulation is to remove a brick or two and observe.Research on here and google the difficulties encountered with all types of cavity insulation.

 

[d4rkcell]

Thanks guys I can't remember who the installer was but it was all arranged through EDF I will pull out the 25 year gurantee certificate I have and see if there are any details about the installer on there and get them to come and inpect.

I suspect that they will deny any liability and deny the cavity wall insulation is the cause of the problem. Any tips on what i should do to convince them this may be the problem? You suggest removing bricks etc. Would this be best to do on my own before inviting the installer back?

I feel I should mention that whilst this is the corner of the room it isn't the corner of the wall thats insulated. Its actually my gable end wall.

Thanks again, you have given me some things to think about and investigate.

Will keep you posted on any developments.

CW

 

[^woody^]

There would be a cold spot at the corner, either no/reduced insulation or maybe some rubble in the cavity at that location

Now that the rest of the walls are warmer, condensation is settling on a cooler part of the wall

It does not mean that the installation is faulty. It could be argued that you now need to adapt your lifestyle to the better insulated property. The wall would need to be opened up to investigate whether the installation is in fact faulty, or you can get hold of a IR thermometer and plot some readings, or better still an thermal imaging camera

 

[jeds]

Thanks guys I can't remember who the installer was but it was all arranged through EDF I will pull out the 25 year gurantee certificate I have and see if there are any details about the installer on there and get them to come and inpect.

I suspect that they will deny any liability and deny the cavity wall insulation is the cause of the problem. Any tips on what i should do to convince them this may be the problem? You suggest removing bricks etc. Would this be best to do on my own before inviting the installer back?

I feel I should mention that whilst this is the corner of the room it isn't the corner of the wall thats insulated. Its actually my gable end wall.

Thanks again, you have given me some things to think about and investigate.

Will keep you posted on any developments.

CW

Just bear in mind that lower corners of rooms are classic condensation spots due to lack of air movement. If there is a gap in the insulation that will now be worse than it was before because the increased gradient between insulated and non-insulated spots. It is tricky to check it out; drilling into the joint might enable you to see into the cavity but it's obviously very limited. A boroscope might be helpful if the cavity is actually clear but if you happen to poke it into a spot where there is insulation you won't be able to see anything beyond. The best alternative is a thermal camera but they are expensive to hire. I'd probably drill a couple of holes if I were you and see how you go.

 

[d4rkcell]

One thing that puzzles me about this is that the cavity insulation was installed over a year ago now and the corner in question has shown no sign of condensation build up since and it only started once we emptied the room and painted etc.

I didn't discover the holes until around November/December just gone and the weather hasn't been great so was leaving them until this time to fill in. They are quite high up the holes, above head height so aren't immediately noticeable. They are pretty large about 1.5 cm diameter so about the size dann09 mentioned are these holes really irrelevant or could they be allowing colder air into any gaps in the cavity and thus causing the issue? I am reluctant to remove bricks.. pretty novice DIY'er but would the way to do this be to use an angle grinder? My father has told me removing bricks sounds easier than it is.

 

[JohnD]

Is the floor concrete or wood?

Is there a potential source of water on either side of the wall such as a radiator, sink , waste, water pipe or dripping gutter?

Tape a piece of clear plastic tightly to the wall. Does water form on the wall side or the room side of the plastic?

 

[d4rkcell]

Hi no potential source of water either side of the wall.

It is the side of my house/gable end and it is basically just an side path down the side of my house.

The floor is wood. I will tape some plastic to the wall and see if any condensation forms on the plastic and which side. I have never seen "droplets" on the wall just varying darkness levels in the patches in the corner. It hasn't gotten any worse in recent days and infact seems to have gotten better though it does seem to get a lot worse when we cook and there is more steam in the house.

 

[JohnD]

look to see that the airbricks are not blocked, and that the path is not above the DPC

it is useful to look under the floorboards for damp or water uner the floor.

 

[d4rkcell]

here are some photos of the wall outside and the DPC and the area where the marks are inside.

The wall has a chimney breast and the damp marks appeared in the cornrs near the chimney breast and the corners of the room (4 marks). I immediately opened windows to ventilate the room and when we got our radiator back on immediately heated the room up. 3 of the areas affected dried out but the far corner at the back of the room hasn't We haven't really had any rain here and as you can see from the photos its pretty dry.

I have tried to keep the temperature of the room at a decent level (20 celsius) indeed we aren't using our central heating anymore as the weather has recently been quite mild.

I have checked all the air bricks with a screw driver and whilst there were some bits of dried debris in some of the holes they weren't overly blocked.

Hopefully you guys will be able to identify the problem better from the photos. I also included a photo of the hole thats on the gable end from when the cavity wall insulation was put in.

You may also notice the DPC seems to stop suddenly, does this look like the DPC hasn't been fully installed by previous owners? Would you guys recommend i get this done down the whole gable end side of the property? The DPC seems to stop about a meter away from where the condensation/damp is forming inside. Would it be a pricey job to continue the DPC along the rest of the gable end?

Untitled

• d4rkcell
• 17 Apr 2013
• 1

Untitled

• d4rkcell
• 17 Apr 2013
• 1

Untitled

• d4rkcell
• 17 Apr 2013
• 1

Untitled

• d4rkcell
• 17 Apr 2013
• 1

The last image of the inside and the marks the part of the wall on the left in that image is the outside wall the part of the wall on the right is an internal wall.

 

[JohnD]

does water lie on that concrete path in rainy weather, or splash up e.g. from a dripping gutter?

Is the wall on either side of that slat dpc newer, e.g. an extension?

 

[d4rkcell]

Hi when it rains it lays on the path there is no guttering as it's a flat/straight gable end. The slat from the dpc isn't part of an extension no its part of the original structure but it looks like a previous owner filled in a window on that corner. There was a lean too shed on the side which I removed 4 years ago since then this side of the house has been exposed but never had any problems until now.