Mould on interior walls and ceiling

[ubonr1971]

We have a room thats directly exposed by the rain on the corner of our building. Its the only room that has mould inside. Whats the best way to prep it before paining. Should I use vinegar or bleach? Any suggestions?

 

thanks

[bankruatsteve]

Not sure what "directly exposed" indicates but mold is usually the result of water leaching.  It won't help to paint until the water source is stopped.  Otherwise, most household cleaners will remove mold including bleach.

[johng]

Water leaking from pipes burried in the floor and walls is a big problem and cause of mould...you must stop the water leak first before any painting is done.

Edited December 29, 2019 by johng

[Dumbastheycome]

Is the  mold actually a result of exposure to rain or is it possible it is a room that is rarely ventilated? Is it only on the exposed wall or thoughout the room?

High levels of humidity combined  with  gloss surfaces can rapidly cause mold growth.

Try cleaning it  and  see if it reoccurs.

[wayned]

I found that the best thing to remove mold and "kill" it is to use Vivol bathroom cleaner.  Be careful and wear protective clothing and gloves as it contains 10% HCL.  Everybody, and I do mean everybody, used it to clean their walls after to 2011 flood.  The cost quadruples at the local 7-11.

[ubonr1971]

On 12/29/2019 at 7:50 AM, Dumbastheycome said:

Is the  mold actually a result of exposure to rain or is it possible it is a room that is rarely ventilated? Is it only on the exposed wall or thoughout the room?

High levels of humidity combined  with  gloss surfaces can rapidly cause mold growth.

Try cleaning it  and  see if it reoccurs.

Im wondering if its a bit of both what you describe. Can you look at the photos and tell me what you think?

 

The room is at the top on the corner and exposed a bit to rain perhaps? I think the previous owners havent opened the windows for 20 yrs. 

 

He put in a new roof a yr ago and thus I dont think its water leakage. Would you agree?

 

 

[ubonr1971]

On 12/29/2019 at 7:48 AM, johng said:

Water leaking from pipes burried in the floor and walls is a big problem and cause of mould...you must stop the water leak first before any painting is done.

Looking at the photo would you think thats its just due to poor ventilation and perhaps that the wall is exposed to the rain being high up on the corner?

 

[CGW]

Lot to be said for using decent AC! sure a lot of those that "never use AC" have similar problems!

[johng]

2 hours ago, ubonr1971 said:

The room is at the top on the corner and exposed a bit to rain perhaps?

 

Yes definitely not much roof overhang to protect from rain, check the gutters are not full of crud  and even with a "new roof"  it can still leak.

[sometimewoodworker]

2 hours ago, ubonr1971 said:

Im wondering if its a bit of both what you describe. Can you look at the photos and tell me what you think?

 

The room is at the top on the corner and exposed a bit to rain perhaps? I think the previous owners havent opened the windows for 20 yrs. 

 

He put in a new roof a yr ago and thus I dont think its water leakage. Would you agree?

 

 

Whoever put the roof on or commissioned it did a very bad job, so no I definitely would not agree.
 

The most likely cause is water running back under the roof so getting on to the wall and saturating it or going through the gutter mounting points and doing the same. The roof should have an overhang with the gutter mounted away from the wall. 
 

With the current pictures it’s impossible to tell and you will need to get up to the roof to find out what’s the problem and if there’s a simple fix.

Edited January 4, 2020 by sometimewoodworker

[bankruatsteve]

Totally agree with Woody ^  

You can see the mold also on those ventilation (?) strips on the near side but not the other making it obvious that the gutter is the cause.  Maybe can get some kind of flashing in there but it doesn't look like an easy fix.

[Dumbastheycome]

4 hours ago, ubonr1971 said:

Looking at the photo would you think thats its just due to poor ventilation and perhaps that the wall is exposed to the rain being high up on the corner?

 

Looking at that I would say it is  more likely  to be seepage from the exterior due to the concentration of the damage. Is your  accomadation  on the top  level or the  next down? If on the  lower level is the effected interior wall mostly the one with the wide concrete lintel the downpipe is mounted on? If so maybe the problem originates there with water not being shed off and away from the  wall?

If you are on  the top floor then perhaps the guttering is clogged and water is running down the face of the building?

Unfortunately if the  water is entering from the outside there is not much on the interior that  can solve it IMO.

[WayWokeWhiteGuy]

How long has it looked like that?

 

Did it look like that before the new roof?

 

What is directly under the roof?

Edited January 4, 2020 by WayWokeWhiteGuy
added note

[Don Chance]

The way to clean it: a scrub brush and some some cleaner solution.

The way to fix it: Remove the eavesthrough, clean the mold and seal the exterior surface with a rubber paint or vinyl paint would work. They stuff is called blue seal that i have used. Another option is black tar.  What they use in Thailand is some sort of water resistant exterior paint, which is not really water proof.

 

Actually, looking at the picture again there seems to be gaps with the black bars coming out of the roof. You can try to seal any holes or gaps with caulking might fix the problem.

Edited January 6, 2020 by Don Chance

[ubonr1971]

the update is that we decided to pull out the old gyprock ceiling that had mould on it and replace it in a few weeks. After that we found that there were some holes in the wall that could thus explain that rain was entering and hitting the old ceiling. I've filled all the holes with silicon and thus problem solved

[phetphet]

I had mould on the ceiling in my bathroom. Used hydrogen peroxide solution, available from the pharmacy, to clean it off. Used one of those plastic  spray bottles to apply, left a minute and wiped off. Worked well.

[johng]

4 hours ago, ubonr1971 said:

I've filled all the holes with silicon and thus problem solved

Has it rained yet ??

[sometimewoodworker]

5 hours ago, ubonr1971 said:

the update is that we decided to pull out the old gyprock ceiling that had mould on it and replace it in a few weeks. After that we found that there were some holes in the wall that could thus explain that rain was entering and hitting the old ceiling. I've filled all the holes with silicon and thus problem solved

The walls near the roof should not be seeing much water on them. So you may have fixed a symptom (you will probably find out the next time you get serious rain) but probably haven’t fixed the cause.
 

Now it’s the cold season is the perfect time to take action. It’s going to be much more interesting to have to do the work when you are getting heavy rain on most days.

[ubonr1971]

On 1/8/2020 at 12:13 PM, johng said:

Has it rained yet ??

He had a huge downpour a few days ago and I got up in the ceiling and couldn't find any leaks

[sometimewoodworker]

5 hours ago, ubonr1971 said:

He had a huge downpour a few days ago and I got up in the ceiling and couldn't find any leaks

Unfortunately not finding leaks doesn’t mean that you have solved the problem.
 

As far as I know you haven’t looked at the gutter and roof beside the gutter, so while you don’t have water running into the ceiling, that may well be the silicone that has stopped that, you almost certainly do have water on the wall, quite possibly onto the top of the wall. Most wall paints etc are not designed for water flowing down them.