Thin flags (pavers) - suitable bedding? - Best bedding method for thin flags/paver

[NicaBaldosa]

A great information source. Congratulations on the site and thanks to forum participants for your contributions.

Having read parts of the web site guide related to my project and searched the forums, I could intuitively (but not with comforting certainty) take a stab at what I need to do. Living in a country (Nicaragua) where the local masons feel that if you can't suck concrete or mortar through a garden hose then it isn't wet enough, and hard-scaping practices, to be polite, are blissfully simplistic compared to those prescribed on this site, I'd feel much better with some help from this forum.

Also, since the project is a 100 sq meter pool deck (light foot traffic only) to be surfaced with 25mm(yes) thick, 400x400, wet-cast concrete pavers (fiber re-inforced), and the site guide and forum topics seem to deal with pavers that are minimally 37mm and more likely 50+mm, I would feel better hearing from forum members if I should be laying these differently than a thicker paver.

Some background: The company making the pavers originally made a 400x400x50 wet-cast paver. Given my sub-grade they said that laying them over a 25mm+/- sand bed of a coarse river sand would be "fine". The sub-grade is a material called "cascajo," Spanish, in this neck of the jungle, for gravel or crumbled rock. And it's basically that--a friable, crumbly rock when broken up/excavated by pick axe and breaker bar that leaves a sub-grade surface that a plate compacter simply bounces off. So, all of my finished deck levels were set to 75mm (50 + 25) from this sub-grade in relation to the pools' edges, retaining wall footings and other landscaping. Come order time, "no hay" (there are not) any 50mm pavers; they don't make them any more. This is Nicaragua. I have one option, the 25mm pavers, baring a prohibitively expensive import.

As for materials, especially aggregates, the range and classifications that are listed on the web site guide simply do not exist here. I have access to the following:
1)crusher run/crushed fines (variable quality grit size; often used in concrete mix as a fine aggregate since it is far cleaner than most sand); 2)12.5mm (0.5") crushed stone; 3)18mm (0.75") crushed stone; 4)beach sand (usually for fine stucco, plaster, repello); 5)"coarser," granular, river sand (usually used in concrete mixes); 6)45Kg bags Portland cement; 7)latex/acrylic bonding enhancers (eg. SikaLatex-N), AND: 8)everything is mixed by hand with very little likelihood of using a mechanical mixer (simply not available-to rent, beg, borrow or steal).

My questions/concerns (plus, at your suggestion, any others I should be thinking about):
1)Given the sub-grade as described, can I work with a 50mm bedding layer to set the pavers? Or less (considering the 100 sq meter area and the amount of material that has to be mixed and placed by hand)?
2)Bound or unbound bedding material? Even though the site suggests, as a very general rule, that small pressed concrete flags can be laid on an unbounded bed, I don't feel that this is an option since my flags (pavers) are not pressed concrete--they are wet cast--and are thinner (more fragile?) than seem to be generally used. However, contrary opinions and suggestions are welcome.
3)If a bound bedding is the better option, are the site guide suggestions for either a moist or wet mix appropriate? Would you recommend back buttering the pavers with a slurry mix? Any suggestions, modifications? We are working in a very hot and dry (windy) climate at the moment (usually starting at 5 am to finish by 11).
4)Pointing. No polymeric sand here. The site guide pointing page states that a 3:1 sand:cement mix is ideal (assuming a bound bedding). But what sand would be best between the fine beach sand and coarser river sand that I have available? There's also some mention of a lime mortar. Is that simply the addition of lime to a regular sand and Portland cement? The guide suggests this makes a better (stronger) mortar and I do have access to lime.

Thanks for reading through the post and your suggestions and comments.

Alan

[lutonlagerlout]

jeez alan you are up against it there
manana ,no hay etc etc
laying 25mm pavers directly on sand sounds no good to me
25 mm is a big tile so it needs to be laid on a cement bound bed
as for pointing i would use exterior tile grout depending on your joint width
i feel for ya
LLL