On Jun 30, 8:32 am, Ook wrote:
Is it possible I did not use enough cement powder? There were no
instructions on the bag, I think we mixed it 6:1. I later found the
1-2-3 formula, which would be 5:1. I used pre-mixed aggregate, my
neighbor had a yard of sand and gravel mix that I hauled to my place,
and we used 5 shovels of that and 1 shovel cement powder. It was a
warm day when we did this, the ground was moist but not wet, and the
area is shaded most of the day. I tapered the concrete so that at the
post it is an inch or more above the ground, and it does indeed taper
away from the post, and I used pressure treated posts rated for ground
contact.

I think the general consensus is to not worry about the cracks? The
posts are most definitely not going anywhere, cracks or not. Will the
cracks let in moisture that can shorten the post life? I don't know
deep the crack goes, they extend from the post to the edge as viewed
from the top, but I've not dug down to see if they run all they way to
the bottom of the post.

Update on cracks - 48 hours later, half of them cracked, and the crack
may be as much as 1/8 inch. on some of them. Just one crack, as if the
posts did indeed swell up (what happens when the posts dry? will the
then be loose in the cement?).

On Jun 30, 8:09 am, "EXT" wrote:

My experience shows that concrete cracking occurs as the wooden post expands
or swells from the water in the concrete mix. I normally reduce the effect
by putting a couple of heavy coat hanger wire circles near the top of the
wet concrete to hold it together as it sets.

"Zootal" wrote in message

...

I set 8 posts in concrete yesterday. Today, I look at them and see half of
them have developed cracks in the concrete, usually just one crack
radiating from the post to the end of the concrete, looking from the top.
Should I worry about this? Is this normal, or an indication that I didn't
mix the concrete right?

My bad - we used *six* shovels of aggregate and 1 shovel of cement
powder.