Questions about building a concrete pier

[bob57434]

Hi, I don't have much construction experience and I'm kind of learning as I go. 

I'm building an 11x14 log cabin which will be supported by 4 piers.  The frost line is 36" so I dug my first hole to 48" and built the pier using cinder blocks.  The pier is built out five 8x8 cinder blocks stacked on top of six 8x16 cinder blocks.  The 8x16's are stacked 3 high so that the base is 16x16x24.  Then the five 8x8 blocks are stacked on top of that which creates a pier that extends 16" above ground.  It is reinforced by #4 rebar.  I have a pic showing this but I can't figure out how to insert it in the post.

My question is this: I poured the concrete in 2 batches - once for the 16x16x24 base and then once for the 8x8x40 section.  They are connected by about 16" of overlapping rebar.  The 40" section felt a little wobbly when I left it to dry yesterday, is this going to be structurally sound?

Another question is this: Should I pack down the concrete (Quickrete) really tight (with the handle of a shovel) after I pour it?  It seemed to compact a lot so I smashed it down pretty good.

Do my plans look sound?

Thanks!

Bob

[alex trent]

I am really not clear on what you did and I think a pic is worth a lot here. it is not all that hard to post on the PhotoBucket.

I do not think four piers is enough. For a couple of reasons which I am sure others will cover better than I.

On the piers themselves.

You say cinder blocks, but reference a concrete pour.  That confused me...did you use the blocks as a form?

On the two separate pours, concrete does not stick together very well, so all you really have holding this is the overlapping rebar, which in my opinion is not enough..that's why you have a wobble and no real sidewards forces on it yet. You need to use rebar in the piers from the bottom up.

Yes you do have to tamp the concrete down well as you pour..as you go along not just at the end of the pour.

[bob57434]

Hi, thanks for your reply.  OK, figured out the pics.

This is what the pier looks like before I placed it in the ground (it has an additional 8x8 block on top).  I used better cinder blocks than those pictured.



This is how it looks before I did the second pour.




How many piers do you think would be enough?

And yes, I used the cinder blocks as a form.

I was thinking of using those 8" cylindrical forms for the next three because I don't really like how this one came out.  Any suggestions on the best way to do this?  I was thinking maybe something similar to the first pier but using the 8" tube instead of the five 8x8 blocks.

Do you think the pier I've already made will be usable?

Thanks again for the help.

Bob

[bob57434]

An additional note on the question of the number of piers that I might need - the cabin will be 11x14 and made of 10 to 12 inch logs.

[alex trent]

A few quick notes....

1. You do not need forms on the part of the pier in the ground...the soil does just fine.  You can build forms for the above ground part only...BUT

2. You should pour the pier as one...don't pour half and then another half.   From the  ground up to the top.

3. You need rebar from the base to the top....something like 3  3/8" bars in each pier all tied together with some smaller  (1/4") rebar and with some spread out feet at the bottom.  Adds a lot  to the strength. Without that i do not think you have a satisfactory pier.

The bad news..

I think you need to redo this.  There are worse. May hold up and may not.  But you will have a lot invested in the place and why start with something that is built on an unsound base. The logs sound heavy..needs more than this. It is not great to redo, but this is not all that much in the scheme of things. Just looks rickety.

I think you need..

Assuming you have decent soll that will support the load of you cabin, and six piers sounds close to not being enough for big logs. So need to check out you soil bearing capacity first. Assume it is 3000 PSF, six piers at one sq. ft is 18,000 lbs total. For your size cabin sound OK.  But if 1500, trouble. Then:

1. Six piers. You will find people on here don't even think any pier is good.  So good reasons too, so it you do pier it, got to do it right.

2. 12 x12 " poured concrete .

3. Rebar from the bottom. to the top with footers.

4. Minimum 4 feet deep.

5. Figure out how you will attach logs to the piers before you pour. They cannot just sit on top.

[MountainDon]

I'm not a "log guy" but it does seem to me that with 10-12 inch diameter logs the structure will have considerably more mass than a structure built with conventional stick framing. With that in mind I believe that a pier at each corner is woefully inadequate. The best foundation for a log structure will be similar to the best foundation for a stick built structure; a full perimeter concrete or concrete block wall, resting on a concrete footing that is also full perimeter. That spreads the load out over a larger footprint and pretty much eliminates the potential problems of having any one pier settle more than the others. Like I said, I'm not a log guy, but piers go against the grain for a log structure, IMO.

If frost depth is listed at 36 inches the bottom of the footer should be at or slightly below that level.

[bob57434]

Thanks Alex and Don for the replies.

Maybe I need to reevaluate my plans.  I have plenty of trees up there and I'd like to use them to reduce the cost of lumber.  Have you ever heard of anyone basically framing a cabin out of logs and then using something like plywood to create the walls?  If I did something like that and made the cabin much lighter do you think I could get away with 4 piers?  I'd like to include a loft too.

I don't know a lot about framing or construction but I'd love to learn.

This cabin is not going to be a permanent residence, it's just a project I've wanted to do since I was a kid so it doesn't have to be perfect.  My biggest concern would be the thing collapsing on me while I was in it.

[Rensmif]

Thanks Alex and Don for the replies.

  If I did something like that and made the cabin much lighter do you think I could get away with 4 piers?  I'd like to include a loft too.

My biggest concern would be the thing collapsing on me while I was in it.

I, like you Bob are still learning, Alex and Don have given you sound opinions, and advice.  they both have builds listed on this forum loaded with pic's, and Alex's build has helpful video's as well, their foundations were dug by hand like yours and are both nicely done.

Trust them please, you dont want to "get away with" anything concerning your foundation.
It's probably NOT going to collapse on you, but may indeed shift or sink and make your dwelling uninhabitable. 

Please keep us updated on your project, every build, and question posed is a chance for us ALL to learn something.

[Don_P]

The old log houses here were typically built on 4 piers, under the hard bearing points of the stacked corners. Remember, load goes to stiffness, these are criss crossed stacks of horizontal beams that form load bearing "columns" in the corners. In an old chink style log house, the logs are beams spanning from corner notch to corner notch. The load on each horizontal log (think beam) is transferred to the corners and then vertically down the corner to the pier. I've never seen one of those that hasn't settled but the understanding and ability to build a good foundation was not there yet. Many were later underpinned with brick or dry stacked stone. I've worked on a couple of those where the unloaded underpinning had collapsed and the bearing was back to the original 4 points. So was it done, yes. The weaknesses are settlement and possible lateral movement. These old pier buildings were almost always at ground level on one side to provide some lateral resistance, an anchor against racking. Which worked somewhat until rot releases that connection.

I've gone back under several of these with a full perimeter wall on footings below frost depth. Then to transfer the loads more uniformly down through the walls to the foundation I installed blocking inside the chink joints in vertical "columns" along the length of the wall and beside any openings. That works well on old fully cured logs, with green logs the corners are settling as they shrink and those columns of blocking can hold things up. The slower you work after getting the roof on the more time you have to tune this in as things dry.

The sill logs which carry the floor and pass under the door openings is then a very critical beam. It carries all the accumulated weight from above up to the header row of logs over the tops of the windows and doors where you again have full length spanning logs from corner to corner. The weight is again transferred to the corners for all loads above by those header logs. All loads are carried on those 4 corners.

The issuse in my mind are the load bearing capacity of the soil, you need a broad enough footprint so that the piers do not sink. The piers need to be wide enough to be stable and avoid overturning. My feeling is that building corners that run 4' in each direction out of each corner would provide that stability and bearing area. That approach really calls for an engineer just as independent piers do. It did come from tailgate conversation with an engineer. I have no problem with any type of construction if done right. Alternative methods can be tougher to get right. Because of that many people wing it. That's where we get into trouble, the things that we either don't know or that we do know that just ain't so.

The floors in those old cabins was often independent of the walls. The floor or wall logs could be relevelled independently of one another. A neat idea but a mighty poor diaphragm to reinforce the base of the walls.

The log house here was basically a horizontal framing system. The cabin could be hewed out relatively quickly, chinked and occupied. As time and funds allowed vertical furring strips were applied to the logs inside and out. White clapboards were fastened to the furring outside, lath and plaster to the inside... you had now arrived and hidden your humble roots. Some folks "made it" and others remained in the old chinked cabin. The ones that usually survive here are the ones that were weatherboarded. The flat hewn faces facilitated applying furring strips although the logs were later hewn at those locations until all the strips on a wall planed in flat. The original hewing also produced logs that were slightly tapered narrower at the top than at the bottom, they were hewing a tapered clapboard type drip edge in the log.

On the weight of logs, remember the prescriptive codes include solid masonry structures. We've got up to 16" thick x 10' tall prescriptive stone walls under part of the current house and a chimney that goes about 50,000 lbs and is only 18 square feet at the base. That chimney would put close to 3000 pounds per square foot on the soil, it would likely sink. We put a 40 sqaure foot footing under it and got the load on the soil down to about 1250 lbs per square foot, (less than 10psi if that helps in thinking about it). Now the soil can bear the weight without the chimney settling.  Getting that snowshoe, the spread footing, right for the soil underneath the load is what prevents it from sinking. In the case of the heavy chimney it probably makes it easy to visualize that the spread footing also needs to be thick and well reinforced enough not to allow the chimney to "punch through" the footing. A wall or pier on a spread footing needs to think about the same thing.

[Squirl]

Concrete does not stick to other concrete well.  That is probably why it is "wobbly". 
There are a few ways people get it to stick to each other.

Mortar.  Mortar sticks well to formed concrete.  That's its job, connecting concrete blocks.
Key way. The joint between a concrete wall and the footing is done through a keyway.  The provides a mechanical joint, even though the concrete doesn't stick well.  It forms like a tongue and groove.  This is usually done by dragging a 2x4 through the footing before it hardens.
Concrete bonding adhesive. This is a special type of glue to join two different pours of concrete.  Pretty cheap too.

Considering you are thinking a very heavy structure on a very tiny number of posts.  I would be especially worried about lateral forces and a wobbly base.

I would start over and mortar the blocks before filling them with concrete, put a keyway between the two pours and use concrete bonding adheasive ($6 at Lowes).

[bob57434]

Thanks everyone for your detailed replies.

A few more questions I'm hoping people can answer:

1. I found this website from an article that contained the picture in Squirl's post.  That picture made me think maybe the pier I already made was okay because it shows a "concrete or crushed rock footing".  Wouldn't using crushed rock be similar to pouring two different batches of concrete since they wouldn't be one solid piece?

2. If I were going to build a concrete or block wall around the perimeter as MountainDon suggested, how would I go about that?  There is a lot of semi-crumbly, large-grain sandstone on the property; could I use some of that in the wall to reduce the amount of concrete I need?

3. The soil I am building on is a very solid clay, how can I find out the soil bearing capacity?

4. I read that "interior piers" don't need to be buried beneath the frost line.  Is this true? Why?

5. I was planning on attaching the logs to the pier by means of a 12-18" piece of rebar that extends up out the pier.  I was going to drill a 1/2" hole in the end of each log and slip the rebar up through it.  Any thoughts?

6. Just to clarify, do I want to tamp down the Quickrete as hard as I can when I pour it?

7.  And the question I'm most interested in is this - could I build this cabin using logs to "frame" it and then nailing plywood up?  I researched timber framing last night and that's similar to what I'm thinking but not exactly.  I'm thinking four 12" logs to create the base (the sill I believe it's called) and then maybe every 3' to 4' using a 4" to 6" vertical log as a "stud", probably connected to the sill and header by a mortise and tenon joint and some nails.  I'd probably have to hew the logs at least a little bit to nail the plywood to it?  Does this sound stable?  Could the 4 piers support this structure?  It seems like a lot less work that doing a full log cabin.

Thanks again everyone!

Bob

[alex trent]

This does not answer all of what you ask, but I am sure others will.  Lots of good info to be had and I would say do not get discouraged from the first barrage of comments.  I found that it's good to stay ahead of the curve and ask as you plan so you have all the opinions and can choose.  As you see already, few things are cut and dried...even though there is tons of stuff written and mountains of code books.  I likely could not have built my place without the advice...at least not as quickly and as well.  But, you will also find a lot of chaff in with the wheat...so read it all and research some on your own and don't do or not do anything based on one input.

On the piers and the pic you saw.  I saw the same one and had a bit of the same experience as you, only I had not started building yet.  There are lots of variable in that discrepancy in what you are hearing and what you saw.  I think in your case it is mostly the number of piers (likely way too few to support your house from swaying or falling down) Some is also the supporting  properties of the soil.  Those are both fairly easy to resolve. As you see, piers are regarded by some as not a good option at all. But, those same guys have great advice on how to do it, so if they do not talk you out of it you can do it and they will help you.  I built on piers because of the slope of the ground mostly. In your case, i guess I would say if you don't have to maybe you should consider a continous foundation.  A log house seems to fit on one better than on piers....asthetically speaking and it sure save a lot of potential problems.


On pouring concrete in two pours....as has been pointed out, there are  ways to help compensate for doing that, but the best way to not have to use those workarounds is not to pour them separately.  No amount of mortar or additive alone will make it as good as a single pour The biggest thing to point out here is that you cannot rely on mortar between the concrete block "forms" to do any of that structural holding.  All that mortar does is stick the blocks together it will not in any way strengthen the concrete inside or do very much to make up for two pours. If you are going to get into all he other things you can do to structurally lock them together, you may as well use a proper form or just pour it all at once. This is not a complicated pier, but you can make it one.

[Squirl]

1. It depends on the weight/amount of piers.  None of the plans sold for that kind of pier call for 4 piers  on a log cabin or are loaded at even a portion of the weight you have proposed.  Also, even for the lightest structures, I wouldn't call the gravel with 8" base an overly stable design.

2. Dig. 36" all around.  12" wide minimum solid footing. Blocks with mortar or surface bonding cement. The more points you load the more soil you distribute the load of the house.  There are many books on about a dozen different foundation designs and all are written into the building code.  If cost is an issue, you can always do the old time way of rocks and mortar, called rubble stone foundations.



3. Clay is the usually lowest bearing and heaviest soil.  Conservative estimates are 1500 - 2000 psf.  Most counties will do soil testing.

4. Interior posts aren't required to be buried only on full continuous perimeter foundations.  This is because the purpose to bury them is to protect them from frost heave.  With a full perimeter foundation, if properly constructed, should not have moisture in the center of the building to freeze and heave the center posts .

5.  For longevity the wood in contact with concrete should be pressure treated or have some type of barrier.

6.  Concrete is not compressible.  If it is going down when you tamp it, you are getting huge air bubbles and voids in your pour.

7. Timber framing is another ball of wax.  It is more complicated than a log cabin, but uses less timber.  Don_P is an expert carpenter in the area.  Witlock built a really nice one two.  This takes a lot more research and reading.  I have read 2-3 books on the subject and still couldn't do it myself.
http://countryplans.com/smf/index.php?topic=5331.0

[Squirl]

I disagree about the mortar.  Mortar has a compressive strength of 1200 psi and a shear strenght of around 100 psi.  It is not a large amount, but on a full block wall it is more than enough shear force for structural purposes and is to code without poured concrete.  Most concrete block walls are typically connected to the footings through mortar alone.

Concrete bonding adhesive has a higher PSI shear rating (1250) than concrete alone.  How that translates into real world applications I can't testify too, but it is rated just as good as solid pour.
http://www.quikrete.com/PDFs/DATA_SHEET-Concrete%20Bonding%20Adhesive%209902.pdf

[Don_P]

Looks like I'm the slow typist, well anyway two more cents.
and on the mortar, yes it has some compressive strength, about 1/3 that of concrete... but if lateral is our concern, and I think that is really what your guts are talking about, concrete has very poor tensile strength. Those rebar cages around the insides of big columns, that takes the tension load as a masonry column tries to bend.

1) The pier shown whether on a concrete or crushed rock footing is capable of supporting vertical load. If the footprint is 16"x16" (1.77 SF) and the soil has a bearing capacity of 2000 pounds per square foot...1.77 x 2000 = 3540 lbs. That probably isn't a big enough footprint when we figure for the vertical loads, the building, occupancy and snow.

If you made the pier wobble you instinctively tested the force that most concerns me with piers, lateral. You pushed on it sideways. And you are quite correctly intuitively concerned, wind, seismic, and boys are the horizontal loads. This foundation isn't up to resisting much in the way of lateral forces. It'll tip over.

But I'll backfill and tamp around the pier up to grade and that will resist the lateral forces. Don't look at the height of the pier while thinking that, look all the way up to the top of the sail on that lever arm. If you experience significant lateral load, there is a pretty good likelyhood that isn't going to resist it.

2) There are links to the building codes in the references and child boards, the foundation chapter is the best place to start getting advice about foundations. Typically, dig a trench footing wide, install rebar under the wall location and above the soil and pour a continuous strip footing about 8" thick x 16" wide for most small structures. The top of the footing is level with protruding rebar sticking up periodically along the wall line, block is coursed on top of that. The rebar is tied to anchor bolts protruding from the top of the wall (allthread perhaps in your situation) and those cells along with the wall top are grouted.

3)Web Soil Survey is a good resource about the soil on your land if you are in the database and/or the tables in the foundation chapter.

4) I cannot find a cite for that. A codebook foundation is an enclosed structure, an interior pier would not have moisture under it or extreme cold. I put them all down to frost depth. If you have 4 corners there are no interior piers and the wind is singing underfoot.

5) In reality yes, but we have to prove nobody can beam it up to the mother ship, that's why I mentioned allthread. In high wind areas I've run allthread and couplings from foundation to wall top with a 3" washer and nut up top.

6) As dry as you can stand it and as hard as you can pound it makes the strongest concrete. Excess water creates voids, vibrating or pounding it removes voids making a denser, stronger mix.

Ahh, vertical log construction, find Pinecone's thread. Yes your idea will work, it probably needs more kicking around to get to sizes and such. This is loading the sill at points along it rather than the four corners I described at such unneccesary length above . I'd prefer a perimeter foundation but if not more piers will share the load. I'd look into an alaskan lumbermill to flatten one face of the logs although a broadaxe would do the job.

[Squirl]

You may find this helpful if you chose to build a block wall or for the rest of your piers if you chose that way.

[embed=425,349]http://www.youtube.com/watch?v=0S864aMMiKA[/embed]

[alex trent]

Most concrete block walls are typically connected to the footings through mortar alone.

That is a different situation than a column and it is downright dangerous to transpose the logic to construction of a column or a cold pour.  In a wall that sits on a footing, the mortar to the footing  is not holding much, no matter how strong it is. The wall is holding up the wall. You won't see many 20 foot high 40 foot wide concrete block walls held together with just mortar. You'll likely see poured concrete columns up and down with rebar.  Down here, even the poor people build with a horizontal column no higher than eight feet up tied into vertical columns which are tied into the footing with rebar.

[Squirl]

Most concrete block walls are typically connected to the footings through mortar alone.

That is a different situation than a column and it is downright dangerous to transpose the logic to construction of a column or a cold pour. 

Um that is probably why I said block walls and not columns.  I was using it as an example that mortar adds strength between cold joints, and does more than just "sticking the blocks together." True rebar adds strength too and I never said not to use it. To say that mortar adds no shear strength at a joint is what I disagreed with. Columns are poured separate from footings all the time in concrete work.  They are usually connected with rebar and a concrete bonding adhesive to make a complete joint, which is even better than just mortar (as I also suggested to do).  There are three ways block columns are usually connected to footings. I suggested all three.   I even posted an example.

I don't know what that has to do with poor people.

[bob57434]

Thanks everyone.

Another question: With that first pier I built, could I have just filled the bottom on the hole with stones and concrete instead of using the six 8x16 blocks?  Maybe have fitted the stones around one (or more) pieces of rebar that stretched from the bottom of the hole to the top of the pier?

[alex trent]

Squirl..

Let me, as a relatively new user who has mined this site for a lot of useful info, and has had to sort out a bunch of junk from the good stuff, find unhelpful about your most recent post and something which I think detracts from the information sharing process. I offer this to you in the spirt of an observation that may help you make better use of your talents and knowledge. This thread is getting sidetracked with this, so this is my last post on this, even though I am sure you will have a lot to say.

The discussion was (and is about columns). You made it about something else to prove a point about mortar on which you are generally correct, but which has nothing directly to do with the subject at hand.  Point one: it's good to stay on point and answer the question at hand....
The point of a post should be to help the readers,especially  the originator, not to show how much you know or that you were really "right". Point two: More importantly, what you wrote could be easily misunderstood by someone and that would be potentially harmful.  When I spoke of the fact that using mortar to fix a cold joint in a column it has nothing to do with the fact that mortar is useful in other situations..like walls. No one disputed the fact that mortar has shear strength and binds concrete blocks together and can be enhanced by an additive because that was not even the subject. But what was said is true about columns. Now you are talking about concrete walls and we are in a log cabin discussion. My rebuttal to your "mortar facts" post was simply to reiterate the point that what you said was not true about the original question, as I found that important point lost in your post about how useful mortar is in which you give examples of walls to prove your point.

The point that was lost on you about "poor people" is that even they, who have limited resources and as such often cut corners, build in the fashion I described because it is so vital.  Sorry for the analogy, which missed the point. I guess you are not the only one who does not write clearly.

[Don_P]

Let's move on.

The footing if thick enough to develop a solid mass can contain large rocks. I've filled a pier hole to grade with concrete and solid stones as an extender. Rubblestone would cover it, greater than 16". I wouldn't use anything crumbly, that would then control the compressive strength, they should be harder than concrete. You still aren't picking up anything to brace the posts from tipping.
These are rubblestone piers, the singles are 20x20". Under all that is a continuous footing. Since concrete is cheaper than the stone mason we poured the 2' wide footings from frost depth to almost grade. To economize we did drop in rock after we got above the lower rebar. I would put the building on a wall, just as under the porch. That isn't going to tip over and provides a bigger footprint.


But, you're ahead of yourself. To figure out how to hold the building up, you need to know a lot more about the building. The better the plan the less wasted time and money.

[Squirl]

The discussion was (and is about columns).

Sorry, certain things lead me to believe the topic had shifted to include better foundation options.

2. If I were going to build a concrete or block wall around the perimeter as MountainDon suggested, how would I go about that?  There is a lot of semi-crumbly, large-grain sandstone on the property; could I use some of that in the wall to reduce the amount of concrete I need?

Hence the videos and discussions about block walls.  Sorry for the thread drift.

[bob57434]

Again, I appreciate the time everyone's spent helping me out.

So I'm probably being hasty but I built the second pier today.  This cabin is kind of an experiment and a learning experience for me, actually if I hadn't screwed up the first pier I wouldn't have sought help on this forum and received all this good advice.  Since it's as much about the experience I'll gain building it as it is about the result I don't mind trying out different building techniques and getting a funky result (e.g. multiple types of piers or maybe a wall that only extends along one side of the cabin).

I got up there and examined my first pier - it wobbles about a half inch in either direction.  The rebar that pokes out of the top seems to be secured to the bottom of the pier though because it stays in place and kind of pulls down into the pier as the top rocks back and forth (if that makes sense).

I think the second pier I built today is better but I'm not 100% sure it is all good.  I've read posts that seem to say that you can put the bottom of the footing at the frost line, my frost line is 36" and my hole is 40" deep.  I used three crisscrossed cinder blocks (see pic) and surrounded them with concrete, filling the rest of the hole up to 24".  The footer is 18"x14" and 24" high.  I used 3/16 rebar this time - two 6 foot lengths running from the very bottom to the very top and two 4 foot lengths overlapping in the middle.  The rest of the pier was made with an 8" sona tube.  As I was filling the tube and packing down the concrete, the rebar got pushed out towards the edges (see second pic), at the bottom of the tube they are more centered.  I will cut the ends of the rebar off when the concrete dries.  I stuck a 9.5" long, 0.5" L-shaped bolt five inches into the top of the pier to bolt the first log on.

My main concern is again about the connection between the pier (the 8" tube) and the footer.  The tube rests on top of the 3 crisscrossed cinder blocks (the footer) and it seems like most of the surface the tube is resting on is cinder block instead of the wet concrete in the voids of the block (the top block is one of those that has 3 thin openings instead of 2 square openings).  Make sense?  I'm assuming that that is not as strong as if it were sitting entirely on wet concrete.  I lifted the tube up a little to widen the base and packed the concrete with a shovel handle down the tube (didn't know if that was a good idea).  Then when the tube was half full, I tilted it a bit to make it level; this seemed to make a void and I was able to pack down the concrete quit a bit after moving it.







So here are some of my questions (lots of them but mostly simple ones):

1.  If the other 5 of my piers are solid do you think there is any way I can get away with leaving the first one the way it is?  I imagine it has plenty of compressive strength, just no resistance to lateral movement.

2. If my frost depth is 36", is a 40" hole sufficient?

3. What exactly is the definition of a "footer"?

4. Do I just peel off the sona tube down to ground level?

5. Is it bad that the rebar is pushed out to the edge of the sona tube at the top?

6. I only used enough water to give the concrete a kind of gravely texture - more solid than liquid, is this okay?

7. Are my pier and footer attached well enough?  Should I push on it real hard after it dries to see if it budges?

8. Is it correct to call the 8" cylindrical part the "pier" and the 14x18x24 part the "footer"?

9.  It started to rain so filled the whole back up with dirt before the concrete was dry, is that okay?

Thanks again everyone!

I'll post again soon with a kind of revised plan for the cabin.  I don't think I'm doing all logs now - too much work and apparently too heavy.  I'm thinking a combination of logs and plywood.

[alex trent]

I cannot figure out why you are using the blocks with the tube on the top.  Or for that matter the blocks at all.

Why not just use a tube all the way to the bottom of the hole? That would solve a lot of concerns you are having and problems you have. 

If it is because the tube is not enough area (which is a good concern), you can pour right in the hole with the rebar in position...lots of ways to hold it....if that is what the blocks are for you do not need them...the hole will hold it all just fine. Put the tube on top of the hole before you pour and pour the whole thing at once. You can just use 3-4 pieces of rebar this way...bottom of hole to top of tube and don't ned any extra pieces in a single pour.

[alex trent]

Quick answers (my version) to your specific questions:

1  Judgement call...IMO, no.

2  ?

3. Depends on what you are referencing... in your case it is the first building element that contacts the soil..other foundation elemenets rest on it.

4. I guess...never used them.

5  Yes.

6. Yes less water is better...up to a point and I bet you are on the safe side of the point.

7 Yes, push it hard. However hard you can push will not be hard enough to prove anything if it does not move ..unless it moves and then you will definitely know it is bad.

8. Close enough..if you had a base under your blocks, that would be the footer.  Your blocks look more like a pier than a footer to me.

9. OK to me..others know more about curing stuff.