Is this foundation safe? Legal?

[chrisgt]

This is an octagonal basement for a geodesic dome. The house needs a lot of work, but I'm concerned with this basement. Will this fail building inspection for the other work that needs to be done?
I can't imagine this is rebar re-inforced. There are some walls that are a bit better than this, some that are a bit worse.

imgur link if image upload failed: https://i.imgur.com/tVq3jT1.jpg

[Jerry Peck]

Can't tell anything from that photo, and clicking "Next" gets some interesting photos ... :confused::(

[chrisgt]

Can't tell anything from that photo, and clicking "Next" gets some interesting photos ... :confused::(

The blocks aren't overlapped correctly. Due to the overlap, I can't see any way they could have correctly rebar reinforced this foundation.

[Jerry Peck]

Presuming that that CMUs are the typical two-cell blocks (one center web), it looks like there is sufficient space for the steel and grout (the "filled cell" would likely actually end up being two or three or more, cells due to the lus-aligned webs).

The best, quickest, easiest, and most understandable way to check is with an infrared camera - you should be able to 'see' everything that is 'filled' (and thus also 'not filled').

Whether there is steel in the filled cells is another question, and you won't 'see' that with an infrared camera.

If the CMUs have two webs and three cells (which I've rarely seen), then you may likely have a good. point.

[chrisgt]

Presuming that that CMUs are the typical two-cell blocks (one center web), it looks like there is sufficient space for the steel and grout (the "filled cell" would likely actually end up being two or three or more, cells due to the lus-aligned webs).

The best, quickest, easiest, and most understandable way to check is with an infrared camera - you should be able to 'see' everything that is 'filled' (and thus also 'not filled').

Whether there is steel in the filled cells is another question, and you won't 'see' that with an infrared camera.

If the CMUs have two webs and three cells (which I've rarely seen), then you may likely have a good. point.

Thanks for the information. In some places the sill plate isn't fully covering the CMUs. Some places I can see are filled, some (most) are not filled. The CMUs are three cell type and I see no evidence of rebar.
I will try to either borrow/rent the equipment to "see" inside the wall or have someone take a look.

[Jerry Peck]

To check for rebar, you would need the tool made for that.

Typically, the rebar is installed at spaced intervals, such as every 4ft, but that likely varies based on the local code, and the engineer, if engineered.

[Jerry Peck]

If the CMUs have two webs and three cells (which I've rarely seen), then you may likely have a good. point.

Not having seem very many 3 cell CMUs walls (almost everything I've seen in Florida are two cell CMUs), I went back to the photo and drew vertical RED lines down where the webs are (at the 1/3 length of the block points), then drew vertical BLUE lines down what was between the webs, i.e., the cells, and the webs lined up with the other webs, and the cells lined up with the other cells.

[chrisgt]

Not having seem very many 3 cell CMUs walls (almost everything I've seen in Florida are two cell CMUs), I went back to the photo and drew vertical RED lines down where the webs are (at the 1/3 length of the block points), then drew vertical BLUE lines down what was between the webs, i.e., the cells, and the webs lined up with the other webs, and the cells lined up with the other cells.

For some reason it's telling me I have to register to see a pictures, it was working fine yesterday... Anyway I understand what you mean, I didn't think about that for some reason. In all of the landscaping and hardscaping I've done, I've never seen a three-cell CMU, so this just looks super wrong. But it does make sense...

[Jerry Peck]

Infrared photos of CMU walls I took almost 20 years ago.

With the house house wall photos, you can see the filled cells ... and the webs ... as the webs affect the temperature of the surface of the wall. Oh, yeah, you can also see the overfilled cells where the cell-blocking pieces were either left out, moved out of place, or torn (if screen is used instead of metal ones).

With the highrise infrared photos, start at the bottom and go up - see those filled cells on the bottom (1st floor), those are supposed to continue all the way up on each floor ... okay, not the excess filled area where they got carried away, but that just makes the wall stronger, even if there is only steel in the 'supposed to be filled' cells and not in the other cells filled accidentally.

Screwing up like that (not filling cells which are required to have steel and be filled (do the unfilled cells even have steel in them?) on a highrise gets costly to fix. Fortunately for the contractor, the owner had me there during construction, much easier to fix before drywall goes on the inside, I kept point the problem out to them from early on, but it took the owner that long in the construction progress to tell the contractor to 'fix it or no more payments will be made'.

Forgot to add two photo of the house, added those with edit.

[chrisgt]

Those pictures are super cool, thanks for posting!
I could see some filled cells looking around the sill plate, so maybe those do have rebar. This makes me feel a lot better. I think I'll still get someone with a camera and knowledge on how to look at the pictures just for the peace of mind.

[Jerry Peck]

I could see some filled cells looking around the sill plate, ...

I would have thought that the entire top course, or top two courses, depending possibly on the block used: bond beam block - https://www.homedepot.com/p/8-in-x-8-in-x-16-in-Bond-Beam-200870700000/301710242 - could make the top source as one continuous course after being filled; otherwise it would take at least two courses of regular CMU block to get some continuity around the top course of the foundation - and even that would be iffy for continuity.

If there is no bond beam, how is the sill plate anchored down to the foundation? Only at the filled cells?

[chrisgt]

I would have thought that the entire top course, or top two courses, depending possibly on the block used: bond beam block - https://www.homedepot.com/p/8-in-x-8-in-x-16-in-Bond-Beam-200870700000/301710242 - could make the top source as one continuous course after being filled; otherwise it would take at least two courses of regular CMU block to get some continuity around the top course of the foundation - and even that would be iffy for continuity.

If there is no bond beam, how is the sill plate anchored down to the foundation? Only at the filled cells?

Based on some other things i've seen in this house, hopes and dreams?

[Jack Feldmann]

In my area they require the top of the wall to be solid block, or concrete filled.

[chrisgt]

In my area they require the top of the wall to be solid block, or concrete filled.

yea, same here. I'm kind of in the boonies and there probably weren't strict (or any) building codes in the 80's.

[Harry Janssen]

In my area they require the top of the wall to be solid block, or concrete filled.

Semi solid or concrete filled