How to identify the cause of paint bubbling?

[HaruS]

Hi,

Apologies if this is not an appropriate question for this forum but I just wanted to ask if anyone knows what is causing this bubbling on top of the skirting board? I scabbled a small section of it to see what behind it and from what I saw,  it was a bit of a gap.
 

I’m just a bit alarmed because behind this wall is a shower.

Any response would be appreciate thanks. 

  

[JacobZ]

Hi @HaruS,

Thank you for your question about bubbling paint at your home.

It is entirely possible that there is an issue with moisture coming through the wall, but it is difficult to tell from these photos alone. 
 

Has the bubbling paint been there for a while or has it only appeared recently?

Does the area where you've scraped the paint away feel damp?

Is there anything else that would indicate moisture? Is the skirting board soft? Are there any watermarks on the floor?

You can use an Ozito 6 -60% 0.2 -2.9% Digital Moisture Meter to confirm whether or not moisture is present. 

If you find that there is moisture present, there's a good chance the shower on the other side of the wall is the source of the moisture in which case I would suggest contacting a leak detection specialist for their assistance locating and rectifying the issue.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob

[Noyade]

It does look like (me = amateur painter) a moisture issue @HaruS 

How does that moisture meter work @JacobZ? What readings are acceptable/unacceptable?

Looks interesting.

Cheers.

[JacobZ]

Hi @Noyade,

This moisture meter uses pins that are inserted into the building material to produce a reading. The pins send a small electrical current between them then measure the electrical resistance of the material and produce a reading.

On the building materials mode on this specific moisture meter, 0.2 - 0.7% is reasonable. Anything above this is damp and is an indication of a moisture problem. 

They're a handy bit of kit for carpenters, builders, plasterers and painters amongst other trades and professions. They are handy for ensuring building materials are in the correct range before installation to prevent issues related to excess moisture.

Jacob

[HaruS]

Hi Jacob,

Thanks for your response. 

I've only noticed the bubbling recently but I suspect that its been there for a while (before we moved in).

The area where I scraped off was pretty dry. I also didnt see any watermarks and the skirting board was soft. 

I did get the digital moisture meter, I tested the area with bubbling and also area around it and all came back within the 0.3-0.7% range. 

I also tested the skirting board and it came back within normal range. 

I'm planning to scrap off the rest of the bubbling, put some filler in and paint over it. Then ill observe whether it comes back again. 

[JacobZ]

Hi @HaruS,

If there's no moisture present, then you shouldn't have any issues going ahead.

If you run into any trouble along the way feel free to reach out, I'm happy to help if required.

Jacob