Moisture in exterior wall

[Globetrot]

Hello,

I don't know if this thread fits here or somewhere else.

A company is building a dormer for us on the south side/shady side of our house. Now it has leaked due to poor coverage with tarpaulin to the lower floor. We have approximately 2-3 dl of rainwater out on our parquet floor on the lower floor. A window, wallpaper, and parquet floor are damaged.

The contractor is going to restore this, but I wonder if the insulation and the window are affected? Should they replace the insulation and replace the window? Or will it not be affected. Mold and moisture are not fun to have in a wall.......

Brrr.

 

[cecar33]

That it gets wet once does not necessarily mean permanent damage, but to know that, you probably need to open up the wall and let it dry out properly; otherwise, it is an insurance claim that falls on the company doing the work.

 

[Globetrot]

How do we know? Should we ask them to open the wall and take a look?

The company has taken responsibility (hard not to...). I'm just wondering if we should ask them to open and look.

The visible "problems" downstairs seem to be drying out well.

 

[Globetrot]

Can the moisture even theoretically dry out in the wall? Can it become 30 degrees if you're lucky... in the wall, that is.

 

[cecar33]

Moisture does not dry due to heat, but with ventilation. As is well known, it's not humid outside if it's several degrees below zero; in the summer, the humidity is greater even indoors.

 

[Locke]

Heat provides the driving force for moisture migration. Sometimes microwaves are used to heat up building components that have become damp, so surely heat is a good way to dry out?

 

[Globetrot]

Thank you. Practical to know if there is sufficient ventilation and drive to dry out exists, should one then measure moisture? When? After 2 weeks, 3 months?

 

[Locke]

A distinction is made between quantitative measurements and qualitative ones. The hard part is interpreting the data.

 

[Mikael_L]

As is well known, it is not humid outside if there are several degrees below zero, during the summer the humidity is higher even indoors.

Well. It is known to be humid outside even at sub-zero temperatures.

In fact, the relative humidity (rH) is often at 100% or close to 100% during the winter months, especially in southern Sweden.
However, the absolute humidity (grams of water / m3 of air) is low, as cold air cannot carry much water.

 

[Globetrot]

Now some time has passed. We have a pin moisture meter at home with two pins that can be pushed into, for example, walls in moldings. At the place where water was running, I can measure over 30% moisture at the tip... in other places in the house, it's under 11%. It should dry out to below 15%, right? Or at what moisture level should you tear out and dry? We have wallpaper, so it's probably not extensive, maybe a wall section of about 2m...

 

[Globetrot]

31-33%...

 

[motives]

If the contractor is going to fix the faults anyway, it's probably just as well to take it down and see what it looks like. That way you can sleep well at night too.

I probably wouldn't be able to handle the thought of potentially having a growing mold infestation in one of my interior walls

 

[Mikael_L]

Now some time has passed. We have a pin moisture meter at home with two pins that can be pressed into, for example, walls in moldings. At the place where water ran, I can measure over 30% moisture in the tip....in other places in the house, it is under 11%. It should dry out to below 15%, right? Or at what moisture level should one tear out and dry? We have wallpaper, so it's probably not that extensive, maybe a wall stump of about 2m.....

What you've used is a moisture content meter.
It does measure slightly differently depending on the wood species and whether you are measuring on the absorption curve or the desorption curve, i.e., during moistening or drying.
But a moisture content above about 15% is not good, then there is a risk of growth and/or other problems.
http://www.traguiden.se/TGtemplates/popup1spalt.aspx?id=1531

 

[Globetrot]

We bought the meter at Claes Ohlsson, but it shows 11% on the plaster on the other side of the house and 33% at the damage. In water, it measures "overload".

 

[Globetrot]

...but we have been affected by an irresponsible contractor so they are likely to argue to the maximum about whether they should fix it or not.....sigh.