One thing that I found from talking to dozens of builders that use pier foundations (including pole barns), is that the perimeter will very likely settle more than the center. This is weight issue. When/if this happens it will create a hump in the center of the floor. The answer to it is to add shims to the inner posts so the floor can be leveled if needed. I chose shims cut from new shingle scraps. I added enough to bring the posts up about 5/16".
Now I can just go under the house and remove enough shims to level the floor if needed.
Peter, I actually considered placing house jacks on top of my concrete block piers to enable easy leveling when needed. We have a saying around here that there are only two types of foundations in Texas, those that have problems and those that are gonna have problems. With our sandy/clay soil, it's just a matter of time. But, your idea is a lot cheaper than house jacks although you can find used house jacks pretty cheap.
Okie Bob
The foundation has caused me a lot of concern Bob. I have spent at least 100 hours looking at old and new pole barns, talking to builders and owners and at least another 100 hours making mockups.
The system I came up with is IMHO the most bullet proof method around. It not only allows me to adjust them, it also allows me to refresh the wood treatment when I need and it also allows for a fairly easy way to change them out if they do need replacement in the future.
Since the exterior poles will go into the finished building I didn't want treated wood. Both for health reasons but also ascetics (they will be visible inside). To solve that problem, and to make replacement of the treated portion easier, I cut tenons on shorter treated 6x6's and grafted them onto untreated longer poles.
The treated poles go into a 5' deep hole with 6' of concrete in the bottom. Angle iron is anchored in the concrete and extends above the hole (If I ever need to replace, I just remove the salt treated from the untreated at the tenon, dig the treated out and bolt a new one to the angle iron)...anyway, crusher run from the concrete to the 2' level. The post rests there. Then gravel dust around the post to ground level.
What I use to treat the soil and wood can be poured directly on the gravel dust. I don't want to give any secrets but the treatment material is free every 3 months or 3000 miles...whichever comes first.
It;s also considered the very best treatment by most builders of rural buildings.
The center piers (everything inside the perimeter ) got the shims.
I have a 10 month old cabin in Texas on piers, I hope it stays solid but looking at the two conversations I'm skeptical but remaining positive; My question to both of you is about skirting; Pressed tin that looks like brick or even corrigated metal? Any suggestions or reasons why nailing to my piers would or wouldn't work? I feel I need to do something since I believe the floor is getting cold even though we've only had a few 28 degree temps;Thanks guys
Welcome to the forum. There should be no reason that wouldn't work.
In the event of pier settling, there is usually enough room with a crawl space to jack and shim if necessary. Depends on your conditions.
If you notice cold there you may want to insulate the floor along with the skirting if not already done.
I am looking for an adjustable pier. I understand that no matter which type of foundation that has been tried in the area that I am building, they all move. Most of the sourdoughs say that it is a matter of how much time you want to spend adjusting each year or so.
I am currently looking at a 30X30" concrete pad with cement blocks criss crossed, with a tube for a jackscrew, filled with cement. Then a typical pier block adjuster (oversize). Any ideas?
Something like this:
(https://img.photobucket.com/albums/v326/Dirtofak/CABIN%20MODEL/Cementpier.jpg)
But instead of the pyramid use 8X16" cement blocks like this:
(https://img.photobucket.com/albums/v326/Dirtofak/CABIN%20MODEL/cementblockpier.jpg)
Any idea what size of threaded rod that would be needed?
Looks like they use around inch in Australia, thanks to our long lost buddy, Jonesy. We have had other discussions here where it was stated that you could use smaller such as 3/4"
http://countryplans.com/smf/index.php?topic=1269.0
(http://users.tpg.com.au/jonsey/countryplans/stumpaj3.jpg)
http://users.tpg.com.au/jonsey/progress.htm