Insulation work in house 1965

[dedeleco]

Hi, do you have any answers and where are you ?????

[Eisenheim]

Hello Dedeleco,

Thank you for taking news even if I have only a few answers to give !!

- the test with the plastic sheet was not very conclusive ... even by looking at different times so as not to be mistaken ... we noted traces of humidity on the outside of the sheet (overlooking the piece) which could sign of condensation, and at certain times also on the inside (between the sheet and the wall) but in a very minimal way, no droplets, just qq traces of humidity.
since we removed the glass cloth and plaster in several places, we found that in this place after cleaning the mold with bleach:

they did not return ... more by removing the glass cloth, we found that the glue remains were wet as well as the plaster, since everything has dried ...

- concerning the kind of beam or ventilation duct, I still don't know what it is ... the neighbors either and at the town hall they could not confirm me in a way or in the other, a friend of a colleague who is in the building also thought of a ventilation duct and then changed her mind when she saw the interior of the house, she does not see why they would have installed one here since the rooms (kitchen, laundry room) are opposite ... and no exit at roof level.

here are some answers to bring ... we also contacted other companies for exterior insulation, prices remain high but we found some additional constraints including the fact that our roof is a concrete slab (or fiber cement) and not a frame so you have to leave cat flaps all along to ventilate the roof, outside the ITE must go up to the top for it to be effective and there I have 2 speeches:
- stop the insulation at the level of the cat flaps and mount the cladding to the top => roughly the ventilation level of the roof is not ideal ...
- go to the top (insulation + cladding) and recreate the cat flaps => there is no risk of creating a thermal bridge that ...

In addition, they have two different discourses:
- one specifies that the DTU requires them to finish the insulation at 18cm from the ground (for new houses, during renovation it is not always possible so it seems that they have more leeway) therefore proposes to lower the insulation below the level of the floor of the house for good insulation => which seems logical

- the other specifies that it is necessary to leave 18cm between the insulation and the ground to allow good ventilation ...

=> basically who is right, one proposes to lower the insulation below the level of the interior floor of the house, which would leave 10cm between the insulation and the ground, the other on the contrary would leave 18cm so the insulation would be above the interior floor of the house ...
the second solution seems less logical to me !!
Finally, this is not very encouraging given the can of artisans practicing this kind of isolation if they do not all have the same speech

[econobrico]

Hello

I recommend that you contact a thermician who can set priorities. In particular, wait for winter and take an infrared photo.

Ventilation cannot be the third priority, it goes hand in hand with insulation if we modify the treatment of water vapor in the house.

Attic: vapor barrier under the wadding provided or not? Beware of wadding with water vapor over time. And also if it is loose the installer must retreat the entire periphery before to avoid air infiltration which after a gale will make thermal bridges.

Insulation from the outside: savings are never recovered. A solution which is a good alternative is the injection into the 5cm of air from the walls if there is this air gap. Injection of beads with binder or injected foam. It is much cheaper and the savings are close to external insulation in renovations.

A:
cork insulation is much more efficient than glass wool insulation with the same R.
In other words spending 150 to get the R of tax credits is useless if an isolation of 100 euros is enough. The 50 will never be reimbursed by aid.

Principle for this type of house
:
Work the airtightness of the roof spaces and joinery.
THEN THINK OF ventilation for evacuating water vapor (15 liters for a family per day).
Then think about inertia and therefore the insulation of the walls. Ditto pay attention to the treatment of humidity and water vapor through the wall.

There are many insulators:
cellulose wadding, rock wool, glass wool, cork beads, polystyrene ball, sprayed or injected insulation foam, wood wool, wood fiber, cellular glass, etc. etc

Apart from the Cork, all the insulators have "environmental defects" but the companies have a very effective marketing to give us the illusion of ecology.

good luck

[Eisenheim]

Hello,

Sorry for this long absence and thank you for the last message.
So I come to give news following my initial requests and problems !!

As a priority, we carried out this work:
- installation of a ventilation system -> we had done a complete new cleaning of the walls (mold) and no more worry about mold in any room except the laundry room (which sometimes remained a little more humid than the others until we isolated it) so it was really the big priority (thanks for the advice) and it's been 3 years now without worrying about humidity

- we carried out the insulation from the outside of the existing house coupled with an annex extension of the house so as to benefit from an interesting eco-loan -> sacred gain in terms of comfort in the house, especially for the boiler which starts much less, we will soon see the result on our heating consumption but this will be really significant even if the big plus is really the interior comfort in the house.

Now here are new questions. The extension was made in brick with a steel pan roof with anti-condensation felt -> the only possibility for the carpenter so as to have a low slope and keep a sufficient ceiling height.
Here is a photo (with additions on what I plan for the insulation of the ceiling):

In my case the air space is ventilated under the steel tank but only by circulation of outside air which passes through the ridge at the top (the steel tank is not glued to the wall) and below by the cat flaps made by the tray grooves.

to see if this remains possible given the distance between the timber 120cm across the width ... the installed furs as I drew all the 60cm will suffice well fixed on the angles (see beams optima so that the furs are better maintained) to hold the drywall?
By informing me in various stores or even by re-reading the DTU, the spacing must be maxi of 120cm so that would pass !!

This is the principle that I saw already used at Isover with Optima:


Typical level of insulation, I mainly hesitate between several because the room will integrate a stove:
- rock wool: better acoustics than LdV, as well as compared to water vapor even mineral wools do not like too much (except with a steel tank which tends to condense even with the fault which limits the effect s 'it is well ventilated)
- wood wool: permeable to water vapor, denser therefore better inertia and acoustic point of view, but more fearful of fire hence the obligation to put plasterboard M0 above the stove.
- panel wadding: not bad too
- cork: too expensive…

The main drawback being the thickness to put because I have to leave a 4cm air space, except my purlins are 18cm thick and counting the structure (smooth + fur) which takes 2cm, it leaves me 12cm to isolate the ceiling…

Don't scream with scandal, I can't do much better because my ceiling height is already low (2,20m at the lowest point) but on the other hand, the roof is therefore low, oriented east and more protected from the sun from 12 noon !!
Hence the need to opt for a denser natural insulation?

Then the second questions are for the insulation of the walls (10cm provided), Then we ask ourselves the question of the insulation of the walls and looking on the forum the subject "insulation guide", we hesitate between these two methods:
- insulation under Optima metal framework


- insulation behind masonry bulkhead:


Level inertia the second would be more interesting especially with the low thickness of insulation that we will put in the room (both on the ceiling: 14cm, and on the wall: 10cm) which is more a room with a wood stove , but that supposes more control on the assembly of a brick or plasterboard counter-partition, and I was asking myself the question of the lifetime compared to the plasterboard facing?
more or less possible cracks over time?


Thank you in advance for your advice.