Papercreters: [papercreters] Re: Papercrete Roof

Tuesday, July 27, 2010

[papercreters] Re: Papercrete Roof

30 Yearss ago when I built my 2100 sq ft house, I put a 6 mill vapor
barrier through out the entire interior of all exterior walls and I
also did the entire house ceiling. To me at the time the ceiling was
more important than the walls. It has proved to be a wise decision after
all these years. I have never had a sweating problem with walls, windows
or doors, and it gets quite cold here in the winter, sometimes well
below -zero. I don't know if it is necessary with PC or not.

BTB

--- In papercreters@yahoogroups.com, "prrr.t21@..." <prrr@...> wrote:
>
> Speaking of buildings in general rather than papercrete
specifically...
>
> In a damp climate its necessary to use a vapour barrier on the
interior side of walls, otherwise as damp interior air cools on its way
outward it condenses, and water builds up.
>
> On occasion people add a vb on the outside to damp walls in the
mistaken belief it'll stop rain soaking in. It may do, but it also
prevents evaporation, resulting in greater dampness in the wall.
>
> Warm interior air holds much more water vapour than even wet outdoor
air in winter, hence the dew point is reached when it cools. The vapour
flow in housing walls is from interior out, not the other way. (If it
were the other way, houses would flood.)
>
>
> Another damp problem happens when a wall has insufficient insulation
to prevent condensation occurring on the interior surface. Only a very
small amount of insulation is needed to stop this though, at least here
down to -20C, so I doubt that would be an issue with papercrete, unless
you're building somewhere extremely cold.
>
>
> NT
>
>
> --- In papercreters@yahoogroups.com, "ndgogiraf" ndgogiraf@ wrote:
> >
> > I think it depends on the outside temperature, inside humidity and
insulation of the roof. Does it get really cold there?
> >
> > If it is very cold outside and cold enough on the inside layer of
the roof vapor barrier such that the humidity inside will condense on
that barrier,
> > AND
> > there is not enough papercrete to insulate the inside air humidity
from this vapore barier so that the temperature differenc of the moist
air when it finally reaches the barrier through the papercrete is ...
something about the dew point.
> >
> > Basicly, if you have enough insulation (papercrete or whatever)
between the inside of the room and the outside vapour barrier, so that
by the time the moist air reaches the vapore barrier through the
papercrete , as it moves through it changes it's ability to hold water
so it will change it's tendency to condense on colder surfaces, and you
will be fine. However if the insulation between the inside warm humid
air and the cold inside of the roof is not enough there may be
condensation (the dew point will be reached?) and mold may form on the
innermost areas of the paper crete....
> >
> > I think.
> >
> > Was hoping some one who knew this stuff better than me was going to
reply.
> >
> > Dan
> >
> >
> >
> > --- In papercreters@yahoogroups.com, Pack McKibben <gakayaker@>
wrote:
> > >
> > > I need some input on papercrete roof's.
> > > I'd like to know what folks have been doing as far as water
> > > proofing. My papercrete roof has, pretty much, always leaked
> > > to one degree or another over the years
> > > ( http://picasaweb.google.com/owlswamp/HobbitHouse# )
> > >
> > >
> > > After reading "Latex Concrete Habitat"
> > >
http://books.google.com/books?id=Uu11_JPY83UC&dq=latex+concrete+habitat&\
printsec=frontcover&source=bn&hl=en&ei=vGtLTNjMOoK78gbt0Ywz&sa=X&oi=book\
_result&ct=result&resnum=4&ved=0CCkQ6AEwAw#v=onepage&q&f=false
> > >
> > >
> > > I painted a Latex Concrete slury mix over my Hobbit House
papercrete roof. No
> > > more leaks!
> > >
> > > My question is....What do y'all think? Do you think the papercrete
won't breath
> > > anymore
> > > and I'm looking at future problems? The LC roof has been on for
three months
> > > and I
> > > don't see any mold.
> > >
> > > Have you (if you've built a PC roof) been happy with it? What
problems did you
> > > have?
> > > if any
> > > PackyMcK
> > > PackyMcK
> > >
> >
>