Question
I am an avid DIYer and with the new house we are currently building in Upstate, NY (Rochester area specifically), I will be tackling my second stone paver patio project.

The first one I built back in 2007 I had paid a company to come out and do the initial excavation (which is a practice I plan on continuing) as the amount of time it takes a bobcat to do the digging and rough grading is money well spent in my opinion and this patio is going to be pushing nearly 900sqft.

My first project was a 20x20 using Brussel block from Unilock. I had a 3ft wall (capped with stones laid at a 90 degree turn) with 4ft pillars. I was pretty happy with the results but this project is larger and the walls will all be curved (yet ending in similar pillars at the entrances).

In researching this (and for lack of proper note taking during my last adventure), I generated a list of questions / recommendations that I would really appreciate if a professional or two could weigh in on, a couple of which are product and zone (northeast) specific.

For starters, I currently plan on sloping 1/8" per foot (1in/foot). This worked well for me in my last project and the old 1in per 4ft would be really noticeable over a nearly 30ft run IMO.

As for the questions / recommendations:

1) I was looking into using AllanBlock/Atlas Block for the wall. I know people seem to fall on two sides of the hollow vs solid, but I love the flexability it gives in the curves (which there will be a lot of). If I go with them (3ft wall/4ft pillars) and build the walls into the pillars for strength and glue the coping layer, will the wall be strong enough for the northeast winters?

2) I have two options for the build. I could either build the patio first (curve it in the general shape of the wall) and then build the wall on it near the edge) or build the wall first and cut the patio to the wall. What would you recommend? If I go with a "wall first" design, how did do I need to go in NY with the wall base.

3) In a wall first design, how do I do the excavation? Should I excavate the entire size of the patio + wall + 6-8in (buffer) then trench the wall down even further, lay the first couple of courses for the wall, then put down my base (compact) and then sand for my pavers right up against my first couple of wall courses? In my last project the wall was an after thought so I have a clean slate here and want to do it right.

4) How much base material for Upstate NY? 6in + 1/2in sand? I should have taken better notes on my last project.

5) What is the easiest way to skreed over a 30ft span? I will rent a laser level for the process but is there a "best" direction to work (i.e. start sand in the corner of the house and move diagonally?).

6) If I am going to add a pergola for shade, should I set the posts in the ground (below the frost line) like I would a fence or build a foundation for it after the patio is installed?

Thanks you for your time and insight,

Jim

Answer
Jim:
Looks like you have done some homework and have a good set of questions here.
On the first question I would typically say that a wall that is only 3' high should be no problem if you are using a good heavy block of any brand. I would not use the small residential grade blocks over 18" ht. But the larger blocks that typically weigh 60-80lbs are perfect. If you go over 3' you may need to add geo-grid or geosynthetic fabric every few courses of block. The only thing that would change my opinion is if there is a substantial surcharge or additional weight on the soil immediately above the wall. Like if the wall was just few feet from the foundation of a house and the house was on the high side. In that case you would need to consult with a structural engineer.

On question two definitely the wall first. Then you cut the final pieces of the patio to fit the space at the edge of the wall. Plus you need to put the footing in first, As for the footing for the wall you need to be sure the base material goes below the frost depth. If your soil has a propensity for significant frost heaving you may want to go with a poured concrete footing verses a compacted gravel footing. I would consult a local structural or geo-technical engineer to be certain. You can probably get the local wall block vendor to answer the exact depth, width and type of material is best for your area.

On question three I would dig the wall footing first and and build the wall. Then move to the patio. If you want to excavate all at the same time I don't see any issue with that. A lot is just preference and should be based on your access to equipment and disposal area for soil, etc.

Check with your local vendor of block for base material depth. I am not familiar with your locale. If no vehicles are going to cross this I would generally think 4" would be sufficient but 6" may be required for frost.

For screeding you can not do it over 30' at one time. You will have to set up a system and do swaths of 8 feet or so side by side. I would use 2 small 1" pipes and a 2x6 dragged across them. when one swath is done you move one pipe and check for level and do the next swath and so on. There are great videos on Youtube.

There are a large number of ways to do post for a pergoal. You could set them first and leave them a little long on top to cut off after the patio is in. You could set footers before paving the patio and drill then epoxy fasteners as needed.  Or lastly, you could set fasteners in wet concrete.

Personally, I would dig holes 24" deep and 12" wide and fill with concrete and a piece of #4 rebar, be sure to cut 2" short of the top. You must be sure to set the top of the footing sufficiently low enough for pavers to go over and between the bottom of the posts. Go to Simpson Strong Ties website for various types of post holders.

Hope this helps you.

Sean J Murphy, LA, ISA, LEED AP

Please take a few minutes to preview my websites at http://www.seanjmurphy.com
and my landscape blog site at http://www.amenityarchitects.com