sharward wrote:Nikodemos wrote:i think you should focus on insulation material that is moisture resistant meaning that it will retain its characteristics even in very "wet" conditions....and mineral wool is certainly not the one!!
On what do you base that conclusion ("certainly not the one")?
This site says "
Thermafiber Firespan, Safing Insulation, Curtain Wall Insulation, FS15, FS25, and
Sound Attenuation Fire Blankets (SAFBs), are
mineral-fiber insulation products manufactured with high proportions of slag (80.6% post-industrial recycled content). The products come in a wide variety of densities, facings, thicknesses, and R-values, as rigid or blanket material. These products have been evaluated by an independent testing facility for low pollutant emissions. ThermaTech products, according to the manufacturer, contain no added chemical fire retardants, are noncombustible, odor-free,
will not absorb moisture or support mildew or fungus, and
will not rot or decay. Phenolic resin content is less than 5% by weight."
Keith,
Just info:
All mineral wool, whether fibreglass or rockwool (minerals) is made water repellent. In fact it's really fibre spun from melted rock or sand or comparable stuff.
However from nature such material (fibre) is more or less hygroscopic and capillar (works a bit like a sponge).
It are the binders (chemicals) which keep the fibre together (otherwise you should have a bunch of loose wool) which makes these boards water repellent.
Hence mineral wool boards will not suck water unless the water pressure is high enough to press the water into the open cells (harder with higher densities).
If you get the water into the mineral wool it reacts completely different than foam. It takes much longer for mineral wool to dry than for foam.
Standard all mineral wool has good moist resistant properties, but anything can rot if the circumstances are really bad (wrong hygro-thermal conditions).
I've seen rockwool applied in a ship against the outer steel skin (theoretically hygro thermal 100% wrong since having a perfect damp screen on the cold = wrong side) which I could take a sample from with a spoon, rather than a knife. It looked a bit like jelly and stunk. It's a bit a strange idea seeing rotting rock fibre.
I've seen rotting cellular concrete falling from a ceiling in a brewery where they cleaned recovered bottles with water. That material felt on a thermal insulating armstrong like suspended ceiling (no ventilation in-between). That suspended ceiling at certain spots came down by the weight of the cellular concrete particles and chunks (was hygro-thermal a complete wrong application).
I had a lot of cotton cloths and fabric sent over in a very good sea worthy packing (same packing as used for sensitive electronic equipment), but it appeared to be opened and stuff was stealed (was lost for 6 to 7 months) were this fabric (which can be washed numerous times for ages) felt just apart.
All of these materials you can put outside in all weather conditions for many years without trouble.
You can alter these water repellent properties of whatever mineral wool very easily, and it's fun to test it yourself.
Put a mineral wool board tilted underneath a water tap. You'll notice it becomes locally wet (water pressure) but it meanly will flow from the board at the surface without penetration into the board.
Now take your bottle of dish washing soap and poor a few drops (a tea spoon) of this standard liquid soap somewhere in the neighborhood of that water.
In a matter of seconds the properties of that board are changed and it sucks itself completely full of water.
And it holds that water much better than foam or a sponge.
If you look for the product GRODAN. That's a standard mineral wool specially made with other binders preserving/enhancing the natural capilar and hygroscopic properties of mineral wool.
That product is sold to breed plants in, just because it's such a good and lightweight substitute for ground, holding water very well.
The mineral isolation product Nightmusic referred in one of his original posts in his first threads, almost certain thanks their water repellent properties also on some added chemical which alters the surface tension and will possibly respond to the described soap test in a comparable manner.
Many, many years back I did a related practical joke on a Rockwool stand at an exhibition. (I knew these guys well in a friendly manner).
They build such a water tap and had a dense board placed beneath it to demonstrate people the water repellent properties of rock wool.
Before opening time and people arriving, I did put a few drops of soap on that board underneath that tap.
These sales guys had NO idea what happened. In no time that board (didactic demonstration they were so proud about) was completely soaked with water and heavy as hell.
Wasn't a problem. They just replaced the board after I explained what I did, and found it fun as well. But this was new to these present sales guys, whom never wondered where these water repellent properties related to.
The only think that happened when I came visiting the stand again is that they (in a fun manner) warned one another telling:
"keep Eric away from that board...."
A typical fibre which in itself is perfectly water repellant is polypropylene (hope I remember name correctly here. I'm not a chemist).
It exists in wool, but never saw it for thermal isolation material.
However we used it as absorption in highly technical gasflow silencers (but is less good absorptive than mineral wool).
It's used as inner fabric in these baby pamper things (don't know name) to keep them feel dry, and also to make from these rags to clean up oil while not absorbing the water (you really can suck up oil from a water surface without them becoming wet).
I don't think this fibre is fire safe, but such wool should be the perfect solution here (but I think expensive before a wall is filled as well).
The wall could fill with water, but it will just release ALL water from the wool from the moment the water disappears.
But anyhow, without having experience, I have the feel that when a studio floats, no matter what there will be lots of damage. Hence I think preventing it to float should be a logical solution.
...You'd have what would look "unfinished." And the while clean-up and rebuild effort might be slightly less work and less expensive, those boards are also much more expensive than plain gypsum drywall, so I seriously question the economics of it.
I'd be building at a higher elevation farther away from the ailing levees of the Sacramento and American Rivers.
New holes may appears later in that wood part, and water may finally make your polyurethane foam fall in the end. I don't know if you have direct acces to the wood part, everything depends. Further, would you have any close pic of the wall part concerned? That would help everybody in helping you, i think.
