Bathroom Insulation (Thermal Bridge and Condensation)

[Melkior]

Hello everyone is everyone
Following the purchase of an apartment last year (studio + bathroom + separate kitchen)
We had the work done by a professional (supposedly, he disappeared )
To my surprise, for the past few weeks, I have observed traces of humidity on the false ceiling of the bathroom.
Attached the plan of the apartment in question, I specify that the apartment is in double exposure, the kitchen and the living room is in southern exposure and the bathroom is in northern exposure.


3 weeks pass, mold spots appear .... I decide then I contact my neighbor above to warn her that there is a water leak.
And the, surprised, the neighbor has not been in her apartment for more than 1 month, I still manage to access her apartment (super nice neighbor) and re surprised .... there are no leaks that could come from her water points and drains, ditto for all copper plumbing (fully visible)

The only option for me is a condensation problem.
I then do my research on the internet (google is your best friend) I then equip myself with PTD1 and I notice then in the corner of the bathroom a gap of 2,5 ° between the middle of the wall and the top of the wall .



So I start to make an opening in the ultra humid false ceiling







And there water flows (not much) and it is possible that the condensation can make as much humidity?


I continue the dismantling of the false ceiling, I still get a little water on the head







I notice that the metallic structures of the false ceiling condenses the humidity

What is the solution to avoid these humidity problems? insulation?
Note that a hygro aerator already works in this room.

[Melkior]

Since the condensation is mainly located on the metal structure I suspect the thermal conductivity of this structure since the room is very small and it is fixed directly on the walls.


Is extruded polystyrene (20 min) by wall and ceiling bonding a solution to bridge the thermal bridge which is in the corner of the room?
Is there still a risk of condensation between the extruded polystyrene on the ceiling?

Thank you in advance for your advice

[Christophe]

Welcome to econologie!

1) Is it the 1st winter that you spend in this apartment? (I presume not since the talk of work done by a pro who no longer exists but better to be sure)

2) Given the "quantity" of water and the extent of the damage, I presume (without being 100% sure) that there was indeed a small water damage! It only takes a few L's on the ground at the upstairs neighbor which have not been fully recovered (or too late) to obtain this result ...

I think that the condensation should have been limited to the level of the false ceiling ... since polystyrene panels do not allow moisture to pass through! Especially if the upper apartment was occupied (now that it is no longer it can actually promote condensation on the real ceiling)

3) Once the source of the water has been found with certainty. Redoing the insulation of your bathroom ceiling will not be a luxury, I advise you to put 6 or 8 cm of extruded polystyrene or polyurethane insulation (2 cm is completely insufficient for a bathroom !!)

It is always quite difficult to identify the source of a humidity problem ...

ps: your plan is made with which software? Sketch Up?

[Did67]

Unlike hristophhe, unfortunately I think yes, condensation can produce a lot of water!

Basically, in your small apartment, there is the perspiration of the occupants (not that you sweat, but you breathe - weigh yourself several times in the evening before going to bed and in the morning when getting up before peeing: the difference of weight is the water that we transpired).

We cook; go on, quickly made of spas that we let boil - a few more dl of water evaporated ...

A shower, and ground floor ...

Day after day, they are dl of water in the air.

And who go where? In winter, directly condense on the cold sparties ...

What is the "hygro aerator": a small "grinder" which is supposed to turn by itself? Not an extractor? And even less a VMC?

[extractor: small electric fan blowing on the outside; VCM: system that runs continuously]

I assume you have double glazing? [if not, there might also be condensation on the windows]

Waterproof ???

If you answer yes to all of this, don't look!

[Christophe]

Unlike hristophhe, unfortunately I think yes, condensation can produce a lot of water!

Certainly but why did it appear if suddenly? Because obviously it is not the 1st winter that they spend in their apartment and thermally, it must have been worse before the work they did ...

So it may remain the fact that the upper apartment is no longer heated and therefore decrease the T ° (corner) of the ceiling and therefore the condensation?

[Did67]

1) I said "I think ...". Implied: I'm not sure.

2) But indeed:

a) work done = waterproofing! (undoubtedly there was an "involuntary" natural ventilation before)

b) when we "isolate" it further increases the "pressure" on the dew point at the coldest point.

For example, if you have single glazing before, you cook your pasta, it "drips" along the tiles. So the humidity "dispersed" in the air is immediately "captured" at the level of the tiles, where it does little damage ...

c) and of course if the apartment above is no longer heated, this greatly accentuates the "cold spot". Especially if the insulation between floors is poor ...


So I think it possible.

But it is not certain, of course.

[Melkior]

Thank you for your welcome and your response,
It is the 2nd winter and also the 2nd summer that we spend in this apartment.
The 2 apartments are practically identical

Here is the history:
During the 1st summer 2012 (August): Water damage following a leak in the upper apartment, the leak was located in the interior wall between the shower cabin and the kitchen worktop at the elbow upon arrival, we had to remove the tiling from the shower to repair the built-in plumbing. Symptoms were wet wall and presence of water under the shower tray (upper apartment)
No damage in the upper apartment.
The damage was mainly at the level of the downstairs kitchen (drop of the glass cloth) and also the bathroom (but the false ceiling did not move), we waited until everything was dry and we redid the canvas of glass + paint in the kitchen and paint in the bathroom around January 2013.

And from September 2013 the problems were resumed again, however the kitchen is intact!

I also wanted to clarify that the readings made with the PTD1 from Bosh, we gave that all the exterior walls of the bathroom are pinkish point except the thermal bridge area where the temperature is even lower by 2,5 ° point of rosé (I imagine that it condenses thoroughly)
With in addition a false ceiling closed with ba13, not ventilated .....

However to reassure myself I will make an inspection of the entire installation of the upper apartment with an articulated telescopic camera, hoping that it is not a leak.

Insulation:
For the ceiling, you are absolutely right about the thickness of the polystyrene.
By cons on the walls, I face a constraint:
Tiles up to a height of 1,5M whose thickness is 2 cm.
I tell myself "no condensation on the tiles, I put extruded polystyrene to isolate the damaged areas (after treatment) and I then turn around with a flat wall from bottom to top."
Is my reasoning adequate in the face of this situation?

Before the works, this apartment had not received the least bit of work for 30 years!
I would even say unhealthy from my point of view!
Single glazed window trace of water flow on bottom, moldy solid floor (must be done) etc ...

In fact I already had the same traces last winter, but since there was a leak, we put everything on the back of the leak






PS: The diagram was made with floorplanner (web interface)

Thank you in advance for your advice.

[Melkior]

CI joins the aerator that I put at the top of the window

http://www.leroymerlin.fr/v3/p/produits ... eur&xtcr=5

With a flow of 90M3 / h I suppose that I even oversized

I did not put a VMC because of the noise, since the apartment is already really small.

[Did67]

It starts how, this extractor (so much more serious than what I had imagined at worst) ...

- on command ?
- timer?
- hygrostat?

[Melkior]

Activated by adjustable hygro sensor