Cinder Block foundations

OK. New construction pier and beam home with cinder blocks for piers at perimeter wall and interior. Pads at grade level and no anchorage to structure visible. I would think the pads would need to be a min. of 24 inches below grade to help prevent differential movement.
Although I am not a code inspector but the IRC Does not appear to address construction of a foundation with 8" x 8" x 16" cinderblock piers. My question is why is this type of construction not addressed in the IRC since this is a typical type of construction seen in older homes and what are some guidelines to follow while inspecting these type of foundations. Any help would be appreciated.

Do you literally mean “**cinder **block” or do you mean concrete block? There is a **big **difference. And how does a pier have three dimensions like that? Usually piers are described by their cross-section: 8x8, or 8x16, or 16x16. I guess you are decribing the block size. What do you mean by “pads”? Do you mean concrete footings? If so, and if they are poured directly **on **grade, and not dug into the soil, are you worried about lateral movement? What force would be strong enough to overcome the friction between bottom of footing and soil and make the footings move laterally?

ok concrete block. Here is a detail that I found from local building department. I have attached it in PDF format. Notice the concrete pad or I guess footing. Its a mininum of 24 inches below grade with reinforcement… Im a little confused, where can I find the information that says you can pour a footing on grade. Thats what I am trying to find. Even the IRC has a mininum footer depth depending on one story or two story home.

If the site matches your PDF, it is not poured on grade. Your PDF shows a minimum 24" below grade.

Around here, that depth (24" below grade) is the minimum in well drained soils.

24" to undisturbed soil.

The concrete block appears to be grouted with concrete. Looks fine to me.

Here’s a paragraph from a local (Central Texas) foundation repair company website:

I understand the pdf looks good. The pdf is something I got from the building department.

The problem is that the new home I inspected yesterday, the pad was at grade level and did not go down 24 inches or until undisturbed soil. I was able to basically touch the bottom of the pad or footers if you like with my hand. The whole house was built this way.

I am trying to find something that says its ok to build this type of pier without going to undisturbed soil. The IRC does not appear to address this type of pier construction but does have min. depth requirements for footers.

Would you recommend further review by a qualified foundation company if the pad or footer was not a min. of 24 inches below grade? Its a hard call for me since I have seen many older homes built this way, doesnt mean its right.

Hey Micheal. How is it going? You got the idea. My opinion is if the footer or pad is at grade level your going to have movement. In a new house I cant see this being a good thing. New home owners dont usually like cracks everywhere. This soil at this site was definitely expansive. There has to be some guidelines on how to do this properly.

If the pier was built like in my pdf I would not have a problem with it.

If you’re going to have movement with the footing at grade, you’re going to have it if it’s founded 24 inches below grade, too. Usually interior column or pier footings are not required to extend the same depth below grade as the exterior footings, and if there is no danger of frost, then there is no reason why footings on grade won’t be satisfactory.

Richard I tend to disagree. Expansive soils are very common in this area and the home I looked at (4 months old) had noticeable differential movement already. In my opinion lots of this settlement could have been avoided by proper pad depth or if you like footers.

Oh. Expansive soils are only on the surface?

See post #3

Shall I list all the things that are wrong with that silly diagram? Starting with the title?

Yes please do, it would be interesting to know what is wrong.


I didnt draw the silly diagram. The building department did. All am looking for is documentation that says you can have a footer or concrete pad at grade level and build a home (not a mobile home) on top of it?

  1. Cinder block would be unacceptable for such structural uses.
  2. If the block is 8x16, then the pad below the block should be minimum 8 inches thick.
  3. The “pad” (footing) must be sized to the load carried on the pier. Who knows whether the size shown is adequate?
  4. The beam must aslo be sized according to the span and loads. Who knows whether a 4x6 is adequate?
  5. There is no need to pour the footing around the block. The mortar between block and footing, and/or the reinforcing bars embedded in the footing, are adequate to resist lateral movement of the block on the footing.
  6. The dimension of the footing, if poured around the block, is insufficient to prevent a stress concentration and probable cracking of the footing at the block corners.

Other than that, it’s fine, except it’s a good example of why the building department isn’t qualified to design your structure.

There are things, very many things, about construction that one will not find in code books or by picking building officials’ brains. The gulf between code minimums and good practice is often a wide one. That is why design professionals exist.

The first question is: are the piers in question interior or exterior piers? the second question is: is the region subject to frost? If they are interior piers in a region which does not experience deep frost, then placing the footing bottoms directly on grade may well be acceptable, and that in turn may depend on the exact soil characteristics in that exact location.

Richard, are you saying a structural engineer might be in order since there is noticeable movement of the piers on a 4 month structure as I stated earlier? For the most part the majority of the homes I have inspected with block piers show excess movement of the pier thus leading me to believe the footer or pad on grade is not the way to go. The builder uses this foundation to save on costs, seriously doubt he had a engineer come out tell him the footer on grade was o.k.
Thats why I am tryng to grather information on how to install a block pier.
From what I am gathering the best practice may to recommend evulation by an experienced foundation company.

Thank you everyone for your comments. Its been helpful.

If there is significant movement at the foundation of a 4 month old structure, it doesn’t matter how it is built. Recommend evaluation and repairs.

Movement in which direction? Up? Down? Laterally? If it’s up or down, it indicates a soil issue, and that issue will likely be present just as much a foot below grade as on grade. If the movement is lateral, what was the cause? Is the beam that rests on the pier twisted or bent laterally as well? Are there signs of distress in the house above which reflect lateral movement? Has more than one pier moved laterally? If so, is there any recognizable pattern to the movement? Lots of questions that need asnwers in order to answer your original question…by all means, refer if you have found something that isn’t right.

The footings are supposed to be below the frost line.