How to determine if damp smell, marks, cracks, mould, on internal walls is from; rising damp : condensation or other

Question

I live on the ground floor of an art deco complex, with 2 apartments above me.

We have lived here for almost 13 years and have never had a problem with damp / mould issues....other than our bathroom that is also houses our washing machine and dryer, that I regularly clean and remove small amounts of spotted mould on ceiling.

I am looking for others opinions / suggestions, through their experience and what you think the cause of our new mould / damp issues might be please

The Internal walls of apartment are made of rendered plaster. The outside external walls are double brick and were recently painted with a 4th or 5th layer of paint in 2017/2018

Majority of my problems are in 2 x bedrooms. Both bedroom walls share an exterior wall.
And ONE (1) bedroom wall also shares the complex's communal laundry wall

The bottom of these walls have recurring mould that has now gone onto furnishings and a horrid damp smell is in everything.

A few areas of the lower parts of walls are now showing a bubble like growth - see photos

And the lower corner wall that both bedrooms share now has a cluster of small bubbles

Mould is now in the crevasses of 1 x wardrobe that shares both the outside wall and the laundry wall

New mould has now shown up in my lounge room, this wall also shares an outside wall and 1 side is a 2 panelled permanent glass and the other side my courtyard sliding door moves towards when door is opened. There is no mould or cracks between the 2 panels of glass So why only the bottom area of lower wall and small areas of wood frame attached to wall?

I am continually cleaning and washing everything. Have hung damp bags in the wardrobe but the smell is again coming back to these clothes.

QUESTION: Do you think there is untreated mould behind this wardrobe and this is why i can't get rid of mould in crevasess' of the wardrobe?

For the past 12 to 18 months, I've noticed more and more cracks appearing. The cracks are at different heights of bedroom walls, some are spider like....1 crack with smaller coming out of larger crack

January this year is when I really started to take notice of these cracks as this was the same time I had to clean mould from all walls and furnishing and wardrobes etc...

Now it's July and some of the cracks have partly lifted from the rendered plaster wall

QUESTION: Why are these cracks in different areas of the walls and why so rapidly the increase of more cracks and the now lifting of plaster?

There is a new 15cm long x 5cm high bubble on the upper wall of the hallway that is over 1 of the bedrooms doors. When I touch these bubbles, they seem firm and don't crack with the pressure of me pushing them.

And since moving my bed into the lounge so Insurance can deal with the issue, I see there are 3 stains... one side of wall and 2 on the ceiling - these are left side of loungeroom and away from the bedrooms but closer to the bathroom that has the clothes dryer.

My 2 x lounges feel really cold when I touch them but not my chair. Looked and found that both lounges now have spots of mould on the lower wooden framework that sits on either my rug or the wooden floor of the lounge room.

The Insurance assessor came yesterday and says there is NO structural damage and maybe a small amount of rising damp but in all my issues of above are from my clothes dryer that lives in my bathroom.

Explained, my kitchen and a hallway are between between the bedrooms and bathroom and there is nothing and has never been any signs of mould

He took photos of the lounge room but didn't see the discoloured stains? If I noticed the night he 1st came to my apartment why did he point these out the same afternoon he was here?

Please let me know what your thoughts are to all of above.

Maybe there is more than 1 factor to my dilemma.

Would appreciate your experienced opinions and possible options please :)

Insurance fellow told me while I wait for his report, I should buy a couple of steel bladed fans and put them at bedroom opened windows height for 1 hour a day.

Realy?

I asked if a trapdoor was a good idea to see if there is anything going on under the subfloor and they said NO.

When I asked if best to move out because of mould, damp issue as I think it's affecting my health as I have very unwell through all this, they replied "absolutely not".

They must of noticed the discoloured stains in my lounge and didn't mention a thing. They are the experts so why not help or give advise? Not just wait for a report that is not looking at the factor and or cause.

They asked a heap of questions and yes we've had condensation on windows but no more or no less in winter months of past years. We've had a clothes dryer since we moved here...so why NOW and why is this showing more and more so fast?

Thank you

Answer 1

One of the big long cracks could be due to moving/oscillating earth issues as seen in houses on a slope or near earthquake/continental plate borders locations or in houses next to (abondened or active) mining/subway/oil field/construction areas.

The cause for the mold issue/other cracks can be inside the walls (leaks in tubes) from tubes/apartments above, even a cracked roof can sometimes result in moisture problems on lower floors only. Of course, asking neighbors for similar problems may help.

Or the mold problem could be caused by too high air humidity and unappropriated venting issues - e.g. in combination with windows having been replaced with new ones with better insulation.

To investigate, 3 simple test devices for air humidity could give a hint. Most of those inexpensive testers are not well adjusted/calibrated, placing all 3 in the same room at a time gives a more accurate averaged value for the relative air humidity.

There are more expensive wall testers which use the correlation between electric capacitance and moisture inside the first few centimeters in a wall or ceiling. It will disclose a problem inside a wall. A thermo view camera can show the different temperatures of the wall (wet from faulty tubes/dry). Maybe there is an option to rent a wall tester and/or a thermo camera.

In order to reduce the humidity, night venting is an easy way, i.e. closing all windows during the day and exchanging the air during the night will convey water out of an apartment.