@homey_bird

To answer your questions as best I can from your description.

1. The "scope of work" that you include at the end of your posts reads like a boilerplate description for a brick patio installation. Here we would be doing closer to 9" of compacted base but that is based on our freeze/thaw conditions in Chicago, not yours in San Francisco. For a non-permeable application it is fairly inclusive with one exception.

It does not reference an edge restraint for the brick. It's probably an innocent oversight but you should still ask.

2. To use polymeric sand on 1.5" gaps for your bluestone part of the application is stretching or possibly exceeding the limits of polymeric sand as I know it.

3. No, the base for the Belgard patio is not permeable. If you want to have a permeable or "open grade" base under the bluestone patio portion you will need to look at free draining gravel with chips instead of sand for the bedding course, which is immediately under the brick. Permeable applications are not difficult but they are substantially different than a compacted base installation.

4. If you are saying the gazebo/pergola kit is going to rest on top of the brick patio that gives me cause for pause. Here we would pour either a full 42" deep footing or at least a 6" slab with 42" piers for a base. No concrete would equate to a failed inspection for us. For pergolas we use a Simpson fastener or equivalent for the posts. For a gazebo kit we would follow the manufacturer's instructions relative to hardware and fasteners. Again, all my experience includes a substantial freeze/thaw cycle that you will not experience.

In closing, remember that all brick manufacturer's have a vested interest in their product being successfully installed. If you are skittish about this contractor then call a local supplier of Belgard and ask if they know this contractor and his/her work.

Or you could check here on Houzz and also their website to see if they have projects shown that are similar to yours. Sit down with the contractor one more time and have some dialogue about your concerns.

Below is a kit gazebo from one of our 2017 projects. The first photo shows the prep prior to us placing the concrete for the gazebo. The second and third photos show the finished gazebo and our installation of a compacted, non-permeable modular patio in progress.

Hope this helps you through the process. Good luck.

Hi K&D and Lars,

Thank you for sharing your thoughts and experiences.

From the responses, it seems to me that the patio will be ok as long as we use it for casual lounging (which is what we intend to do). Also, I understand the importance of the bordering brick/concrete to "hold" them all together. We plan to place a rug and some lounging chairs on this patio under the pergola. I imagine that the patio itself would be stable enough for this -- but correct me if I am wrong.

Permeability: thanks for the comment on permeability of pavers. Since the whole area will be under a metal canopy, rain will not directly fall on the patio pavers (barring the bordering pavers). Therefore, I am not so much concerned about the patio absorbing water. My concern was that the yard itself loses 120sqft of dirt patch and will have less ground to absorb rainwater. Not sure if I am overthinking....but that was why I was thinking of ways to harvest the water in other ways.

FWIW -- we will not be sitting under this canopy in falling rain. Our interest is in using this patio during Spring, Summer and early Fall. However, the pergola will stand stormy winds occasionally. The yard can get pretty windy. We have had our patio umbrella get airlifted in the past.

- I understand and forgot to mention, that I am aware that the pergola base (the 4 posts) cannot simply rest on the paved patio without causing a disaster. Our plan is to put 12"x12" or larger if required, concrete base(s) on which these posts will stand. It was discussed with the contractor and was not included in the initial description because (I guess) the conversation was primarily for the sake of budgeting, etc. However, the discussion needs to really focus on where the posts of the pergola will land.

- Lars, thank you for letting me know about the pre-cast footings. My question is, how tall were they and how deep did they go below the grade, to balance that pergola successfully?

- If I were to pour these footings in-place, then how deep would I need to go? Will the pergola spec point me to that? Where do I need to look?

- Here's the picture (link) of the pergola: Planned Metal Pergola

I should also mention that the section of bluestone and the pergola patio are two distinct sections, separated by ~5' of perpendicular distance between the two.

Thank you again, and look forward to more learning :-)

We got something like this - I don't remember exactly, but HD only sells two different types and they are pretty similar. You have to check them closely at the store. My pergola is wood, and the roof is not completely closed, although it is about 80% closed; i.e., only let in about 10-20% of sunlight.

We did not pour concrete around our footings - just gravel, but you might want to use concrete around yours, since yours is metal (and therefore probably heavier), and your roof appears to be closed - more like a gazebo - and this may have some effect with regards to wind. We get very little wind in our back yard.

You should be able to contact the mfg regarding footing requirements, if you cannot find that in the installation instructions. Since my friends is an engineer, he was able to determine what I needed, and I would not have known otherwise.