Blade of ventilated air in stone house

[basjulouti]

Hello everybody

Well, I'm a bit new to renovating and I need advice

I have a stone house on three levels, the walls are quite damp, I would like to insulate on the inside with glass wool followed by a vapor barrier then placo.
I wanted to leave an air gap between the stone wall and the glass wool in order to circulate air from the outside by drilling a hole and sliding a small pipe through the bottom of my partitions. From above I thought of using a 25 or 40 mm diameter sheath that I would pierce on a regular basis. This sheath would be fixed on the top of the wall still between the stone wall and the insulation and then would be connected to a vmc.
The vmc would not run continuously.
I thought I would do this to remove excessive moisture from the wall caused by thermal bridges.
The stone walls are 50 cm thick

Thank you for your criticism and advice.

(I specify that I cannot call upon professionals for financial reasons, I have four children and very little income)

[Obamot]

Good evening and welcome,

It is better to avoid at all costs putting mineral wool with damp walls. This is what disintegrates the insulation very quickly. In addition to put such a material inside, there is a great risk of inhaling micro particles of LDV. I wouldn’t do that.

The only reasonable solution is to put the insulation outside (not inside). So it solves your humidity problems.

[basjulouti]

Hi,
thanks for the answer, I can't insulate from the outside because I'm on the side of the road and the sidewalk is not wide, so grill for me
thank you for your advice
good night

[Obamot]

Hi,
thank you for the answer, I do not insulate from the outside because I am on the side of the road and the sidewalk is not wide, so grill for me
thank you for your advice
good night

Learn well because the legislation has changed and now a municipality can no longer oppose an ITE (around 230mm approximately).
It is necessary to verify, but in certain communes I am sure that it is admitted, I heard cases.
Obviously I do not know the configuration of the place, but a street has in principle 2 sidewalks.
And widening a sidewalk, in any case it is the job of the municipality to take care of it (it should not be your problem, at worst a signage would have to be installed to encourage pedestrians to cross).

[basjulouti]

The sidewalk is only 60 cm, right in the bend, a very small town, hence the fact that the town can not do much.

[Obamot]

What matters is not so much the width of the sidewalk but above all the road surface. I doubt that it is not possible to add a simple curb edge of 20cm, and in this case it would solve your problem. In addition, there are insulators with a reduced thickness but with an insulation coefficient similar to double LDV. If really it is not possible to put curb, it is enough to put on 2m high in 100mm, then make a step and finish with mineral wool.

If we are looking for technical solutions, we always find them (as long as we act on time ...)
But again, the problem of the sidewalk is not yours, this is what you can suggest to the technical manager of the Dpt in case of impossibility raised against you. If the law has changed you have rights.

As it stands, in this type of construction with thick walls, an ITI is always a big source of trouble (to be avoided at all costs). Because if you already have humidity, an Internal Thermal Insulation (ITI) is to be avoided, since this will amplify your problem by the creation of cold bridges. And therefore by increasing the Ƽ it will produce even more humidity than at present, it is inevitable (except by an ITE.) And the more you heat, the more the Ƽ will increase and the more you will have an increase in humidity ... It's a vicious circle.

In any case, you first have to do an assessment to determine the current source / cause of this moisture. While doing work, we must act to remove this cause. It seems imperative to me. Damp walls that go too long without being sanitized can see fungus growing in their thickness (also a point that you should definitely check). Otherwise the mortar crumbles and the walls can end up falling: if that happens it is more than a disaster because there are cases where the house has to be razed. And the owner can do nothing about it when a prefectural decree has decided. It can give you leverage to get the right to do an ITE in order to "save" your house.

[Obamot]

PS: You did not say in which corner and at what altitude this building was located? Anyway, an ITE in self-construction, costs less than a proper ITI (the finishes are much more expensive than a facade plaster and an ITE requires less insulating surface, since it avoids to insulate the walls perpendicular to the facade for about 1 meter to avoid thermal bridges. Itou for the insulation of floor-facade junctions, which is not necessary with an ITE, except on the ground, but it is a lot less critical.)
And of course the installation of 2V windows must be budgeted. It is also to be taken as an "investment". Since the whole will be amortized over 4 or 5 heating seasons, due to the fuel savings achieved.

[Christophe]

I have a stone house on three levels, the walls are quite damp, I would like to insulate on the inside with glass wool followed by a vapor barrier then placo.

Hi and welcome here.

Here is an old topic that should interest you: renovation-works-real estate / how-to-insulate-a-stone-wall-by-the-interior-t13414.html

[Obamot]

Another point that surprised me:

I wanted to leave an air gap between the stone wall and the glass wool in order to circulate air from the outside by drilling a hole and sliding a small pipe through the bottom of my partitions.

I think you have not fully understood how thermal insulation works.
By making an opening, and by circulating air between the insulation and the wall, you will:

- prevent a certain thermal stabilization of the interior wall.
- break the effect of the ITI since it will be extremely difficult to prevent air circulation between the interior of the rooms and the volume of circulating air that you will have created from scratch from the wall to the insulation .
- de facto lower the temperature of the wall on the interior side and thus create a permanent thermal bridge "even more efficient" since at its lowest temperature, therefore with the highest possible humidity rate, since the Ƽ will be extreme at this place (such as the unpleasant misting effect on the windows of a car in winter, when the passenger compartment is heated).
- set in motion an air gap, which to have some insulating characteristics, should imperatively remain motionless!

It is a bit like if you drill a hole in the wall of a fridge, thinking that in this way you would drop the humidity inside! You will instead increase the phenomenon where it should not be, in its buffer zone most sensitive to heat exchange. And your compressor will run continuously to compensate for losses!

If you are thinking of a bottle of water taken out of the fridge in the middle of summer, it is precisely the air exchanges of different temperatures which cause the formation of condensation bubbles on the surface of the bottle! This is what you are going to accelerate / amplify against all expectations, since your goal should precisely be the opposite (lower the humidity.)

From above I thought of using a 25 or 40 mm diameter sheath that I would pierce on a regular basis. This sheath would be fixed on the top of the wall still between the stone wall and the insulation and then would be connected to a vmc.

There it is even worse, since you create a link between 2 "systems" which by definition should in no case be connected. In fact it is the classic situation with an ITI, we keep creating problems that did not exist before!
When you do an ITI out of spite (because you cannot do otherwise and after having exhausted all the other available solutions), you must take care plug all airways with the outside (not create them), like technical sheaths with PU foam, sheaths of electric cables with silicone, put plugs to condemn the ventilation ducts, put lintels at the bottom of doors which have none not, over-insulate the blind boxes to again avoid any air circulation, etc ...

We are therefore not going to create a system that could compete with precisely what we want to avoid: either any exchange of calories / frigories between "systems".

The vmc would not run continuously.

VMC is only justified when a high level of insulation is obtained, amha. And if you reach a high level with an ITI, this is the beginning of the problems that arise and that must be circumscribed. I think it is wiser not to create them at the base and therefore to give up an ITI (especially when you are the owner and you are the master of the decision).

I thought I would do this to remove the excessive moisture in the wall caused by thermal bridges

The only way to remove moisture is precisely to avoid its creation / manufacture via thermal bridges resulting from the side effect of an ITI. CQFD.

[basjulouti]

no sidewalk in front, it is a wall of domain, and no possibility of widening the road, it would be necessary to create another, therefore very hot history.
The house has a great cachet from the outside with its stones and bricks, in the street all the houses are of the same type, the slightest request for modification of the facade is apparently complicated (window, roller shutter ...)
is there any possibility of interior insulation, without giving a risk of fungus to this stone wall?