Insulation by the ground, basement of the house

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Hello,

I'm going to do floor insulation in our basement this summer.
The basement includes a cellar, a laundry room, a large bathroom and a corridor + toilet. For the moment, there is only a tile laid on the ground (no chappe).

The basement is quite damp, which is not very pleasant for the bathroom, not very practical for the laundry room to dry the laundry, and not very healthy for the cellar with the equipment (tools and others) which are stored there.
We also have problems with paint that does not hold on the walls, and joints between crumbling bricks.
So I'm looking for a solution to regulate this humidity. I will place an extractor in the bathroom.

For the moment, I was referred to a hedgehog solution of washed pebbles + visqueen + cork slab insulation + clay concrete + finishing floor (clay or terracotta tiles).
For clay concrete, the store sells the Argilus brand.

Are there any other solutions?
Do you know of any good stores to buy all of this? I live in Liège. I was told that there are interesting stores in Germany (lower prices and VAT), but I don't know where to find this info.

Thank you!

[Obamot]

Hello and welcome!

You do not specify if there are windows in the basement overlooking "asus"? As following:



Your cellar is above all a technical vacuum (depending on how you seem to describe it) that is its initial function. Apart from good ventilation by leaving any openings in the open air permanently (window / s open / s permanently), there is nothing to do as is.

If you want to do "living rooms"by just settling for what you believe to be a question of isolation, you will start to see unsuspected problems of all kinds, but more serious than what you currently have => because we must take the problem from the right end (it would be necessary to make an inventory on the spot to identify all this but it is an obvious and known thing. This is not the first thread of this type, do your research here)

So there is no other solution than to evacuate this humidity ... which is precisely the role of a technical vacuum ...

To rehabilitate that, and change the initial destination of this volume. You should know HOW the house was built and WHAT materials (walls).

In the absence of plans, it is necessary to embark on sanitation works.

If the slab can be easily insulated by putting in an insulating material, a waterproofing sheet and the use of an appropriate floor covering, that will not solve the humidity issues that come mainly from the walls!

The only solution for these, is to excavate the topsoil all around the construction (be careful not to break the drainage) to clearly distinguish the different layers of sand rubble and pebbles of different particle size during the operation. Since these are responsible for discharging water (and this to the foundation soles). Then allow the walls to dry and then apply a tarred coating to them, then once dry, surround the house with a moisture barrier like PVC film type DELTA-MS. And finally to re-fill everything as excavated (following the layers: topsoil and other embankments and respecting their initial order) ...

Only then is it possible to rehabilitate the interior.

Not doing this exposes you to taking all kinds of risks for your construction => including cracks and other infiltrations and to assume the consequences. Because the pressures exerted by external wet flows are extremely powerful.

However, this is the ideal time of year to start this type of heavy work.

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Indeed, each room is windowed. The bathroom has 2 windows of the same kind as the illustration you put.
During the evaluation of the building, the expert said that it was a good idea to do the chappe for comfort, he also spoke of plates of a type of gyproc which let breathe the wall but would give comfort to the level temperature, I think later do a ceiling with lime instead.

The house is over 100 years old, the walls are made of brick. The conditions (neighborhood, dead-end pedestrian street, etc.) make it more difficult to insulate against humidity from the outside.

It is more a renovation for comfort than a rehabilitation.

According to the information I had, clay concrete was used to regulate humidity and the extractor improved the comfort of use of the bathroom. The cellar and the laundry room are permanently ventilated by the windows.

[dedeleco]

The humidity of subsoils buried in the ground has two very different possible origins to be separated, otherwise we can be wrong and have disastrous and unforeseen results, believing to improve, by ventilating.

1) Especially on an old house with not waterproof walls and floors, moisture coming in through walls and floor.
The best is the waterproofing from the outside with drainage of the foundations, currently done on all normal new houses.
Otherwise very expensive companies, seal the walls by injections.
Without external peripheral drainage, it is very very difficult to avoid infiltration if the pressure of the external water higher than the ground is strong.
In this case, an automatic drilling and pumping of this water reducing the pressure is a minimal solution.

2) condensation of outdoor air humidity on colder walls, especially in summer, even if the walls and floors are perfectly waterproof !!
In that case, the more you ventilate with warm outside air a little humid in summer, the more its water vapor will condense on cold walls and floors and make them hyper-humid, even if they are perfectly waterproof !!
Serious thermal insulation of interior floors and walls greatly reduces this phenomenon, 2 which exists in new houses as well with well-sealed floors and walls, but colder as deep soil in summer.
This type of condensation is strong in summer and not in winter when the ground is warmer than the outside air.
This difference between summer and winter allows us to discern.
On the contrary, winter rains increase type 1) infiltration in winter, often at specific locations.
This info

The house is over 100 years old, the walls are made of brick. The conditions (neighborhood, dead-end pedestrian street, etc.) make it more difficult to insulate against humidity from the outside.

suggests that you have both effects 1 and 2 at the same time and therefore even more difficult to remove.
Since you raise the problem in summer, I think that 2), condensations, is stronger than 1) predominant in winter ?????

With 2) the ventilation only worsens the condensation !!

This type of basement with humidity was ideal for having a saltpeter which was used for gunpowder, more than 150 years ago !!

If a business or advice don't explain these 1 and 2 clearly and how it resolves each one separately, you have the right to strongly doubt this enterprise !!
Indeed it is very easy to assert a solution by being totally mistaken !!

1) it is drainage or even pumping, more sealing of the walls and their ventilation with very dry air (otherwise condensation on the cold and no drying) !!

The 2 is not to ventilate especially in summer and insulate the walls thermally.

If poorly thought out, the result may be worse than before.

Finally, understanding the concept of dew point in a concrete way is essential:
http://fr.wikipedia.org/wiki/Point_de_ros%C3%A9e

In Europe, air above 25 ° C in summer always condenses its residual water vapor (apparently dry at 25 ° C) on a waterproof basement wall at 15 ° C or less with plenty of humidity. unbelievable !!!
We can completely be mistaken, confuse condensation with a water leak !!.

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The problem is raised in summer because it is more pleasant to do this kind of work during holidays and when the weather is nice ..;)

I never noticed a difference in humidity level between summer and winter.
I also don't think the cellar is unusually damp, for a cellar .. the only difference with a normal cellar .. is its use as a bathroom.

A drain could be installed in the layer of the hedgehog of stones. Is it worth it? Is it necessary?

The work here is really to gain a few degrees by insulating for heat and trying to cut the humidity effect, hence the clay.

The expert who came to assess the house said that the whole basement was healthy.

Am I completely wrong in my approach?

[dedeleco]

Try to separate 1) and 2) and did the expert come in winter or summer?

Did he explain to you the "cowardly" of condensation ??

The expert did not see any infiltration of clean water, wet stain, if it is healthy.

But in winter the risk is higher of arrival of liquid water.

The bathroom increases humidity and therefore condensation in summer on cold walls.

The pebbles are perhaps a kind of drain connected with the outside already which helps to make healthy, ie to drain the liquid water towards the outside which could go up in the cellar. ???
To check !!

In this case, only the soil water remains through slow evaporation.
waterproofing the floor and walls should remove the effect 1)

Then, if waterproof, a good thermal insulator should prevent condensation.

Your info:

The basement is quite damp, which is not very pleasant for the bathroom, not very practical for the laundry room to dry the laundry, and not very healthy for the cellar with the equipment (tools and others) which are stored there.
We also have problems with paint that does not hold on the walls, and joints between crumbling bricks.

shows that it is not as healthy as you want it, even if the expert finds it healthy, compared to other much worse cellars !!

The paint and the crumbling joints show a certain humidity by effect 1) and 2) at the same time.
I do not see why clay will change the problem since it retains the permeability of walls by insulating a little.

If we do not explain you in a reasoned physical way by identifying the effects 1) and 2) separate, you may not resolve !!
Putting bathroom moisture sources and tumble dryers in the already damp basement cannot help solve the problem.

Try to evacuate the humidity generated in addition directly to the outside, without it invading the cellar, or bringing in hot humid air from the outside, so by putting a special air supply limited to each of these.

[Obamot]

Indeed, each room is windowed. The bathroom has 2 windows of the same kind as the illustration you put.
During the evaluation of the building, the expert said that it was a good idea to do the chappe for comfort, he also spoke of plates of a type of gyproc which let breathe the wall but would give comfort to the level temperature, I think later do a ceiling with lime instead.

The house is over 100 years old, the walls are made of brick. The conditions (neighborhood, dead-end pedestrian street, etc.) make it more difficult to insulate against humidity from the outside.

It is more a renovation for comfort than a rehabilitation.

According to the information I had, the clay concrete allowed to regulate humidity and the extractor to improve the comfort of use of the bathroom. The cellar and the laundry room are permanently ventilated by the windows.

Well the proof that no, since you have this kind of problem ... I don't understand your reasoning. You have a cause and an effect. How do you want to treat the effects sustainably, without tackling the causes ...

The great danger is that by insulating from the inside, you will prevent natural drying out by the air and contain the humidity outside in the walls, which will weaken them and eventually rot the binder. . And by phenomenon of capillarity see the problem move higher.
It all seems extremely hazardous to me and I think yourexpert»Is possibly an architect - and therefore does not have the required knowledge - and not a BE engineer.

You are the one who sees, but in my place I would never have fun to solve such a problem lightly. I see a risk of subsidence there.

In any case now, you are informed.

[dedeleco]

If the moisture in porous walls builds up behind thermal insulation and ends up in abundant water, the lime binder of the bricks will slowly disintegrate and totally destroy your wall, much more than what you see happening on the surface today !!

Circulating air there in summer by condensation will give even more water and will end up in the same demolition !!!

This problem is scientifically a real cowardice very very difficult !!

You have to see specialists in ancient churches and monuments !!

Bricks are worse than good stones from old monuments !!

Try first not to have the condensation of steam water added by your baths and dryer !!

Pay close attention to the path of the renewal air, otherwise condensations and vacheries !!