12x12 ft patio. Will be mixing my own concrete - i have a borrowed mixer and the materials needed. My soil is clay type and there is no grass. Water tends to collect where my patio will go.

Reading online said 2" gravel for drainage and pour 4" slab on top. I will be using a pattern form that is 2" tall. Was told by a friend to press the form into the poured slab up to the top of it. Looking online seems you place the form on the plot and pour concrete into it. Thats fine. Except concrete store guy said no drainage needed, put sand as a base and pour on top.

So my dilemma is, I have 2-4" inches of sand as some spots vary in depth. Sand is leveled. But I have approx 3.5" (2x4 form around 12x12 plot) to ground level. So my form is only 2" tall and water tends to collect at that spot.

So questions
1) Drainage - do I need it? how do I accomplish this now?
2) Can I add 2" of gravel to raise the patio up? possibly also fixing the drainage problem if thats a concern.
3) Should I not put gravel on top of the sand and add 2" of sand instead then pour on top of that?
4) I have a path way I need to do as well but have not dug. Should I dig 2" and put in 2" of sand or gravel then pour? or dig an inch or so deeper so the pattern form sits an 1" below ground level?
5) Do i need to leave in my 2x4 form in the ground around my patio and pathway to keep/hold it together? Needed or overkill?

 

Are you planning on using those Quickcrete plastic forms?

 

If that Quickcrete form is what you are using it's not good for a large patio area.

I did a 20" walkway years ago thinking it would save me some money, it did, but was a lot of work and to be honest, looked cheap as hell when done.

One of the problems is the huge gaps, if installed on a patio with any kind of furniture legs they will always be falling into the gaps.

 

Yes a mold like that but a different pattern. Im not sure how you prepared your walkway but Ive seen good results 1st hand from those that have done it. Also I'm not sure how your patio furniture fell in the gaps? Did you not fill them with mortar or sweep sand or anything?

- Should I dig up the sand and put gravel then sand down? Would I be ok just adding gravel to the sand? Can I add dirt on top of the sand then gravel? I will use a tamper on the base as well.

 

My typo, it was 20' of walkway.

Joints were filled with sand but unlike a paver patio where the joints are 1/8" wide the mold has joints 1/2' wide so anything that happens to sit in a joint, or the taper on the side of the "stone", will just fall into the joint where the sand is weak.

No issue with the base just would not consider for anything that had chairs and tables sitting on it.