Why do walls in a house without an outer finishing layer get wet?

Question

Why do walls in a house without an outer finishing layer get wet?

The brick house had been standing for six years without finishing, there were no problems with the walls getting wet. Last year the repairs were made, and the wallpaper was glued. The repair went on for six months, and during that time, too, nothing got wet. This year, in January, the house began to live, two bathrooms were used. Soon I began to notice fungus on the wallpaper, and only on the interior walls, at floor level and up to half a meter in height. The wallpaper began to peel off a little. On the outside walls, where the radiators are, everything was clean. The other day I found wetting and efflorescence on the facing bricks, only in the lower rows, so far only on two walls. Decorative stone, which is used for facing the foundation, is swollen, it is kind of cracked.

What could be the problem? There is ventilation in the bathrooms, the exhaust fans work.

Hennie

Answers

– Hennie · Answer 1 · 2022-09-08 18:23:16

It looks like there is no waterproofing of the foundation, and what 8 years the house took in itself, now gives away.

Debuilder

But it is somehow very strange. All these years everything was dry, and all of a sudden the moisture began suddenly? For example, three years ago we were gluing facing stones on the foundation. If there had been the slightest moisture, nothing would have stuck, right? The inside of the house has stood for six years with no trim. It started out with brick walls, then stood plastered for a couple of years.

If the foundation had drawn water, there should have been some signs, moisture stains, efflorescence, etc. after all these years, shouldn't there have been? None of that happened. The problems have only appeared in the last six months. In addition, wet spots appeared only on two walls, and not along the entire length. At the same time, the fungus on the wallpaper in all the rooms on the first floor, on the interior walls.

Did the problem occur after the heating was turned on?

No, the heating also worked in previous years, but not always. There were seasons when the house was cold. But, for example, last year there was renovation from February to August, the heating worked, and everything was dry, no fungus or moisture on the bricks.

– Hennie · Answer 2 · 2022-09-11 20:02:35

You have nothing to do with ventilation or walls – then there would be no containment downstairs, the upper corners would get damp.

You have something with the basement (waterlogging) – the sewer/water pipes may be leaking. The moisture is most likely from the ground.

A flooded basement takes all summer to dry.

Carmen Gordon

There is no basement in the house. A monolithic strip foundation about 1.5 m deep was laid and a monolithic concrete slab on top of it. All poured at the same time. Regarding sewer and water leaks – thanks for the idea. The first floor has underfloor heating, so maybe it's leaking. And if the sewer was leaking, there would probably be a horrible smell. And as it is, it just smells damp. The question is, how to check all this?

Another thing I don't understand is why there is mold on the bottom of the wallpaper only on the interior walls. And on the outdoor ones, which are wet and high on the outside, there is practically nothing on the inside.

Also noticed that outside, in the areas where the walls are soaked, not only the foundation cladding is swollen, but also the paving stones laid on the concrete sidewalk around the house. I easily picked up a couple of stones with my fingers. Underneath them, the concrete base was damp, too. It looked as if water had oozed from the brick walls, flowed under the facing bricks on the foundation and under the paving stones. Then, apparently, it froze and spread out the stones. That's just my guess.

– Hennie · Answer 3 · 2022-09-12 15:38:37

The slab (if it is a slab) should hang in the air, and if it is on the ground – there is no need for a strip foundation. If you mean slab – floors on the ground, they should be waterproofed and separated from the walls.

A radical move is to dismantle the floors and lay new ones on the joists (this is if the warm floors are leaking).

And to make a decision will have to drill holes along the wet walls (inside the house) to determine the level of wetness – below the floor, flush with the floor, above the floor.

Fidelis

The slab rests on the strip foundation, like a cover over it. But whether it hangs in the air is doubtful, because I remember that inside the foundation were some blocks of soil. If I remember correctly, the reinforcement was placed in this mold, and then all together it was poured with concrete. I do not want to lie, after all, eight years had passed, and I did not build it myself, I just watched. But as far as I remember, all the earthworks were wrapped with roofing felt before the pouring

Is there any way to determine whether there is waterproofing and in what condition? Maybe digging up the foundation in some places? Drill holes in the floor, close to the walls? What is the approximate diameter and to what depth?

Yes, the closer the better (but not in the strip of the foundation), the depth – to pass the slab to the ground, the diameter of 1 cm, the task is to determine the level of wetting and the place of maximum moisture Digging under the foundation (to see the transition from wall to foundation) would be the most correct solution, but how to do it inside the house – the inner walls get wet.

Especially attention to the places of passage of water pipes, sewerage and heating – it is possible that just leaks some pipe, and for your case is enough just a bucket or two of water a month, and there will be such a result.