Do the prefab concrete piers (that 2x8 lumber can insert into) work well for supporting free standing decks (approximately 12 x 19 ft) and only 12 inches high ?
Deck support post piers or ground anchored helical footings by: Editr
The prefab concrete deck piers that can hold either 4x4 or 2x6, 2x8 joists are a useful product for sure. But they are not meant to be all things for all people.
They save having to dig holes, pour cement etc. But ultimately depending on your climate and your soil type they can settle. This may not be a big worry if you can gain access every few years and to a little shimming to level things up if ever needed.
Also, if the soil is quite soft you could place the deck pier/block over top of a 2'x2' patio paver stone to act a bit like a footing and spread the weight.
So for the average guy there is a utility to these especially if you have fairly stable soil that is not prone to moving through out the seasons.
Otherwise the next step up in my opinion is a ground anchored deck support footing system that goes in easy with a hand held impact wrench.
This could be a real time save depending on the exact nature of the challenge you are facing.
I won an inflatable 6 person inter hot tub. I have a large deck. 12x 20 on both sides of the house. With a header to the house and the deck was built 6
I'm putting a swim spa into an inground concrete bunker and will build a deck around it. I have been advised to keep the deck joists a minimum of 6 inches