Tips for attic insulation lost cellulose wadding

[jennypi]

Hello everybody

After reading a few topics about wadding insulation, which the file on cellulose insulation very complete, I open my own subject to have some advice.

My wood frame house has 25 years, I just bought it. The insulation of the attics lost is tight, so I would reisoler. Cellulose wadding is my favorite, considering its qualities and price.
At first I thought I would do this myself, but after reading that the cotton wool was very difficult to "break" and to spread, I called in the pros for quotes.
The first of them told me that my current insulation was a kind of "old" cotton wool and that we could keep it, and put 1 cm of new cotton wool on it.
He also told me that it would be necessary to add a "binder" (sodium silicate according to the estimate: harmful?) Because the valleys are too windy, the cotton wool would fly away. The binder would make a kind of crust on top of the cotton wool.
The 2e told me that the current insulation was rockwool ...
So I do not know which foot to dance on. If it's really rock wool, I prefer to remove it because the ecological side of the wadding would lose its interest. But if I remove it, I should do it by myself because it is very expensive (more expensive than re-isolation) and the house is difficult to access (impossible to approach a truck).

FYI, the 1er made me an insulation quote with Cellisol wadding 1200 € for 26 cm 52 m².

I attach some photos so that you can give your opinion on the nature of the current insulation, the quote, and everything else!

Thank you in advance for your advice because I am a little lost!

Edit by moderation, photos put on the image host of the site

[dedeleco]

A priori, the heated rock wool does not burn while the heated cellulose wool burns with fumes!
We must make the difference by heating and burning a little outside the attic (not to fire).
Cellulose to 250 ° C, yellows and ends up chewing like paper!
An electric soldering iron should blacken it gradually to 250 300 ° C, as for paper!
Rockwool will be less changed.
sodium silicate is a binder and a flame retardant agent in principle corrosive so concentrated and therefore with gloves and ventilated ..
http://en.wikipedia.org/wiki/Sodium_silicate
http://scienceamusante.net/wiki/index.p ... _de_sodium
If the current wadding is with boron it will resist better to heat, but will eventually darken almost without flame, to 300 ° C.
http://www.isolation-ouate-cellulose-vendee.com/
http://www.ouate-de-cellulose.com/question17.html

[Christophe]

The old insulation is clearly not wadding, it is actually a flock of flake rock wool or glass ... I lean rock.

The pro who tells you that it is "old cotton wool" does not know anything about it a priori and is therefore to be avoided.

If the insulation is still in good condition, no need to remove it, it is still "active", especially check its humidity with a moisture meter of this type: https://www.econologie.com/shop/humidime ... p-128.html (The insulation pros should all have one)

For the anti-dust "crust", if you want to do without it, see if you can not rather fill the leaks in your attic at little cost. I did it personally in the file you cite.

[chatelot16]

Sodium silicate is a product that can serve as a glue: liquid when it is full of water: hardens by drying

when it is daubed on limestone it makes a chemical reaction that makes it insoluble after complete hardening, but on wood there is no reaction, the silicate will remain soluble and redisoudra if there is too much moisture

problem of ever waterproof tile that lets too much draft with the water that goes with it

the current solution is the rain film under the tile

my solution is a polyethylene film on the insulation but with obligatory ventilation force of this insulation stuck under a waterproof layer

I prefer a small electric fan sending just what is needed when it is necessary, but not letting wind and storm make any loss

[jennypi]

Thank you for your answers, it complicates my story again!

In fact, the tiles are not totally waterproof. I could see during the last rains (quite exceptional in the corner, it is true), there was infiltrations to the ceilings ... besides the current insulation has taken a shot too, he is wet in some places.

Christophe, at first I can not isolate my roof like yours. Maybe the picture is misleading, because the part we see is the one where there are solar panels above, they are held by boards below. But elsewhere, there is nothing between the tiles, the frame and the insulation of the attic. When we are in the attic, we see the rough tiles what.

Does the rain film fall under the rafters holding the tiles? I could add it and only after thinking to reisoler the attic?
The other solution (polyethylene film + ventilation) seems to me more expensive and complicated, it cools me a little ...

[dedeleco]

Crucial foremost, insulation or other plastic:
Look for and change the tiles broken, cracked or badly put !!
The frame will be damaged !!!
Take a ladder and go on the roof by attaching (harness and rope) !!

It happened to me !! Attics can sometimes change tiles.

[Christophe]

problem of ever waterproof tile that lets too much draft with the water that goes with it

the current solution is the rain film under the tile

And not a vapor barrier placed very cleanly since if there is really too much draft, the external moisture (fog, mist ...) of the air will eventually be absorbed by the insulation ...

I think that measuring the current humidity of the attic (in hazy weather if possible) and the insulation in place will give an idea.

+ 1 cuicui, if there are roof leaks, even exceptionally, they must be repaired as quickly as possible ... before placing an insulation! That way you can see for a few weeks if it worked!

my solution is a polyethylene film on the insulation but with obligatory ventilation force of this insulation stuck under a waterproof layer

I prefer a small electric fan sending just what is needed when it is necessary, but not letting wind and storm make any loss

Pkoi? If there is a vapor barrier between the inhabited part and the insulation it does not seem necessary to me if?

[jennypi]

Hi everybody,

So obviously, we went up on the roof, thinking that there were broken tiles / misplaced. We found one, but only one, while we had infiltrations in many places! In other places, RAS, it is assumed that it was too much rain + the wind that made the water run under the tiles.

How is a vapor barrier installed? Under the tiles or under the insulation?
There are not any kinds of plastic films to agraph properly under the rafters and draining the water that goes under the tiles to the outside of the roof?

[Christophe]

The vapor barrier arises between the inhabited part and the insulation. It is often integrated with chemical wool (aluminum or polymer face)

Maybe the rain screen will suffice, provided you can evacuate stagnant water ... But it is fixed under the tiles, so requires the removal of these (large site).

[dedeleco]

A single broken tile demolishes a house very quickly !!
This has happened to me many times, 1999 end storm with holes in my family's homes, and others !!

So get on the roof (roped for safety!) And look carefully for any broken tiles (not always easy to see, crack!) and change them urgently !!
Go back on the roof and hungrily search for almost invisible cracks to other places that are fleeing !!
The rain must not go under the tiles with damage !!
Do not suppose, look carefully, (with magnifying glass, well lit) and check by watering vertically to detect the path of water that you do not understand !!

That's what I do every time !!!
.
The equipment, ladders, rope, harness, for me, costs less than one intervention by a professional, and you are not sure of the care of his work!
because its interest is to make you remake all the roofing unnecessarily by denigrating the roof instead of looking for the few broken tiles, which you will find very dear! !!!

In addition this same material is used to prune my trees, even those of my neighbors who block my eyes !!

I insist, because the insulation to improve is a detail next !!

The tiles must be waterproof and if not, with water damage, you have broken or displaced tiles, or big mistakes on the roof!
Examine the entire roof carefully, but you have 90% chances that a correction job and change some tiles makes waterproof !! Locate the leaking area! even water to check!
Do not spend the winter in these conditions.
At worst put a tarp on the leaking area !!

Redoing a roof with breathable plastic film and a little more insulation is expensive, 20000 € typically for common villa!

The vapor barrier arises on the hottest side, so inside !!
It serves to block the passage of water vapor from the heat that would otherwise condense to the colder side in the insulation, wetting it to the point that it is no longer useful! (just as hot, humid air condenses in a cold fridge in large quantities)