In my humble experience cement sticks to paper when thrashed. When a mixer full of PC sits for 10 minutes, water (that looks clean enough to drink), "floats" to the surface. It really is the paper sinking but the point is that there is no loss of cement to the water dripping away. When you mix water, paper, cement and some latex, the latex washes away with the water. If latex paint clean-up is done with water it is water soluble. I can't see putting latex in with the mix as an economical means of preventing water ingress, nor with it in the finished structure (wall or roof) as a viable means of water egress. It would be much more efficient to put on the outside it would seem.
This issue of roofs of PC is an interesting one. Roofs are roofs. They are there to repel water to protect the structure beneath. Outside of sod roofs (that leaked when heavy or consistent rains fell) most people that don't like drip buckets all over the house have gone to something that works well (shingles of wood, asphalt or tile, or metal roofing. It would seem reasonable to use PC where its strengths are (insulation, sound deadening, and compressive strength) and leave the roof for the materials that have proven themselves over time.
Sure, some have used PC successfully as a roof material, but could everyone? If you don't live in an arid region, and your waterproofing failed, your roof could fail due to weight, let alone the aforementioned dripping and consequent ruination of the interior. It can be used in the rafters of the trusses for insulation or sprayed to the underside of the roof itself but needs to be protected by a roof. Spaceman's domes are built strong so they can withstand the extra weight of added moisture between long intervals of drought and drying. Similar structures in more moist environs could suffer catastrophic failure due to the added weight (especially if accompanied with a live load of wind). Why go to all the trouble of building a PC house and then have the roof fail? In Nick's post he ended with "it should last for years" but it should last for decades if protected properly.
I live in Alaska where it rains frequently. Out in the bush I have come across many old log cabins that would be perfectly livable except the roof is sitting on the floor inside the building. Old timers used what they had and generally the roof was whipsawn boards, sometimes covered with dirt. With water penetrating the roof the rot and weight caused the failure but the walls remained intact.
From: "prrr.t21@btinternet.com" <prrr@talk21.com>
'Latex' paints contain pva and/or acrylic binders, which are a long way short of the level of waterproofness needed for outdoor use as a binder here in England. I dare say they'd work in a near desert climate, but over here much more waterproof compounds than those, eg PU, are inadequate.
I don't fancy my chances with a highly porous roof material with a little added water soluble binder, I can't see it has any realistic chance of keeping dripping wet out of the building.
The only way I can see that might work for a roof here is to saturate the topside of the papercrete with bitumen in solvent, using a thin mix first to get it to penetrate as far as possible. The result would be excessive drying time, making construction problematic. Hopefully the insulation value of the unsaturated papercrete would prevent too much condensation, and what does occur could hopefully dry out without dripping. If the material cracks, the roofing would soon saturate. My thinking is this should be more durable than bitumen felting.
--- In papercreters@yahoogroups.com, JUDITH WILLIAMS <williams_judith@...> wrote:
>
>
> I have experimented with adding latex paint to the mix. The first batch I did was about 5 gallons paint to my 200 gallon mixer. I plastered a small area of wall just to see what would happen and 5 years later it is still up there. I live in a dry climate so cannot advise you but I would say it's worth a try. Make a batch and try it out.
> I am thinking of doing something like this when I plaster the roof I have onthere now. I have a papercrete roof on each building. On the first one I laid down a good base of slurry then placed blocks into it and covered the whole thing with seems to have worked out OK. On the second building I put down those reed mats they sell at the store. On top of that I put some of that foil wrapped insulation that comes in a roll. I put 3 layers of papercrete over that. It hasn't leaked but is too thin. Some of it has lifted a bit so I'm going to put more papercrete on top of it in the spring. That's where I may add some paint to the mix.
>
>
>
> Follow progress on the new project at http://www.papercretebyjudith.com/blog
>
> More papercrete info at http://squidoo.com/papercretebyjudith
>
>
> To: papercreters@yahoogroups.com
> From: prrr@...
> Date: Tue, 24 Jan 2012 00:31:56 +0000
> Subject: [papercreters] Re: Papercrete roof panels?
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> I'm interested in a small papercrete roof, probably for next year. I live in a wet climte in England, and if I used plain papercrete I'm sure they'd become saturated with water in winter, and make everything inside rust & rot. How could that be prevented? I gather a waterproof overcoating tends to cause problems.
>
>
>
> Regards, NT
>
>
>
> --- In papercreters@yahoogroups.com, JUDITH WILLIAMS <williams_judith@> wrote:
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> >
>
> >
>
> > I have done 2 papercrete roofs. I just continued the walls right up and over the top. Pics are in my blog. I have noticed some cracks at corners of doors and around the perimeter of the roof itself. I think adding more cement to the mix would have prevenedt this. I plan to go around and fill all cracks with expandable foam before plastering. I am no expert on this. Just learning as I go along. I would think the Currys in TX had done some papercrete roofs. They are not in this group but have a blog. I will give the link in the next email.
>
> >
>
> > I also experimented with roof panels. I made them about 30" x 48". I made the form, poured half the slurry, set a piece of wire fence over that (in the middle) then poured the rest. It is important to let it set up completely before moving it. I moved mine too early and they warped.
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> >
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> > Follow progress on the new project at http://www.papercretebyjudith.com/blog
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> >
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> > More papercrete info at http://squidoo.com/papercretebyjudith
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> >
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> >
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> >
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> > To: papercreters@yahoogroups.com
>
> > From: tatsass@
>
> > Date: Sun, 22 Jan 2012 15:37:34 -0800
>
> > Subject: Re: [papercreters] Papercrete roof panels?
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> >
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> >
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> >
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> > ..lex terry in new mexico did...
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> > im not sure if he is on this group...
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> > i know he is on facebook ...
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> >
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> >
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> >
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> >
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> >
>
> > From: Alan <rustaholic777@>
>
> > To: papercreters@yahoogroups.com
>
> > Sent: Sunday, January 22, 2012 2:41 PM
>
> > Subject: [papercreters] Papercrete roof panels?
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> >
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> >
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> > Has anyone here done a papercrete shed with a papercrete roof?
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> > Alan in Michigan
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> >
>
I don't fancy my chances with a highly porous roof material with a little added water soluble binder, I can't see it has any realistic chance of keeping dripping wet out of the building.
The only way I can see that might work for a roof here is to saturate the topside of the papercrete with bitumen in solvent, using a thin mix first to get it to penetrate as far as possible. The result would be excessive drying time, making construction problematic. Hopefully the insulation value of the unsaturated papercrete would prevent too much condensation, and what does occur could hopefully dry out without dripping. If the material cracks, the roofing would soon saturate. My thinking is this should be more durable than bitumen felting.
--- In papercreters@yahoogroups.com, JUDITH WILLIAMS <williams_judith@...> wrote:
>
>
> I have experimented with adding latex paint to the mix. The first batch I did was about 5 gallons paint to my 200 gallon mixer. I plastered a small area of wall just to see what would happen and 5 years later it is still up there. I live in a dry climate so cannot advise you but I would say it's worth a try. Make a batch and try it out.
> I am thinking of doing something like this when I plaster the roof I have onthere now. I have a papercrete roof on each building. On the first one I laid down a good base of slurry then placed blocks into it and covered the whole thing with seems to have worked out OK. On the second building I put down those reed mats they sell at the store. On top of that I put some of that foil wrapped insulation that comes in a roll. I put 3 layers of papercrete over that. It hasn't leaked but is too thin. Some of it has lifted a bit so I'm going to put more papercrete on top of it in the spring. That's where I may add some paint to the mix.
>
>
>
> Follow progress on the new project at http://www.papercretebyjudith.com/blog
>
> More papercrete info at http://squidoo.com/papercretebyjudith
>
>
> To: papercreters@yahoogroups.com
> From: prrr@...
> Date: Tue, 24 Jan 2012 00:31:56 +0000
> Subject: [papercreters] Re: Papercrete roof panels?
>
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>
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> I'm interested in a small papercrete roof, probably for next year. I live in a wet climte in England, and if I used plain papercrete I'm sure they'd become saturated with water in winter, and make everything inside rust & rot. How could that be prevented? I gather a waterproof overcoating tends to cause problems.
>
>
>
> Regards, NT
>
>
>
> --- In papercreters@yahoogroups.com, JUDITH WILLIAMS <williams_judith@> wrote:
>
> >
>
> >
>
> > I have done 2 papercrete roofs. I just continued the walls right up and over the top. Pics are in my blog. I have noticed some cracks at corners of doors and around the perimeter of the roof itself. I think adding more cement to the mix would have prevenedt this. I plan to go around and fill all cracks with expandable foam before plastering. I am no expert on this. Just learning as I go along. I would think the Currys in TX had done some papercrete roofs. They are not in this group but have a blog. I will give the link in the next email.
>
> >
>
> > I also experimented with roof panels. I made them about 30" x 48". I made the form, poured half the slurry, set a piece of wire fence over that (in the middle) then poured the rest. It is important to let it set up completely before moving it. I moved mine too early and they warped.
>
> >
>
> >
>
> >
>
> >
>
> >
>
> > Follow progress on the new project at http://www.papercretebyjudith.com/blog
>
> >
>
> > More papercrete info at http://squidoo.com/papercretebyjudith
>
> >
>
> >
>
> >
>
> >
>
> >
>
> > To: papercreters@yahoogroups.com
>
> > From: tatsass@
>
> > Date: Sun, 22 Jan 2012 15:37:34 -0800
>
> > Subject: Re: [papercreters] Papercrete roof panels?
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> > ..lex terry in new mexico did...
>
> > im not sure if he is on this group...
>
> > i know he is on facebook ...
>
> >
>
> >
>
> >
>
> >
>
> >
>
> > From: Alan <rustaholic777@>
>
> > To: papercreters@yahoogroups.com
>
> > Sent: Sunday, January 22, 2012 2:41 PM
>
> > Subject: [papercreters] Papercrete roof panels?
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
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> >
>
> > Has anyone here done a papercrete shed with a papercrete roof?
>
> > Alan in Michigan
>
> >
>
__._,_.___
