What not to do with a concrete block

Thu Jul 30, 2009 7:20 pm

While working on this side:
Image

This happened on the other side:
Image

Won't do that again!

Re: What not to do with a concrete block

Thu Jul 30, 2009 7:25 pm

First i'm glad your ok. We had the cinder block experience many years ago too.

I've seen those old metal milk crates give out too. We seen those bumper jacks just give out and come flying down too just as my older brother said they ain't safe. We can't trust anything but solid material. (steel/wood)

The big timbers are great for blocking stands too. I have some 8"x 10" oak to use time to time.

BTW; Nice looking project. I been eyeing the old cletrac's lately.

Re: What not to do with a concrete block

Thu Jul 30, 2009 10:13 pm

OUCH! :o :o Also glad on one was hurt!

That is a lot of weight, even if you had put a larger block on top to better distribute the weight. I see people using cement blocks all the time turned with the "holes" horizontal, a bigger accident waiting to happen! As noted, solid cribbing is the best way to go.
Keep safe, good luck,

Re: What not to do with a concrete block

Fri Jul 31, 2009 8:23 am

I never trust cinder blocks!!To much air in them.They turn into cinders.glad no one was hurt!!! Kevin :shock: :shock:

Re: What not to do with a concrete block

Fri Jul 31, 2009 8:38 am

WOW! Good news that no one was hurt!

Actually "cinder blocks" have great compression strength.
That block would have held the load except: (this is not criticism, just trying to help others stay safe.)

1. the blocks must have a solid and flat spot for the bottom. Any deformities in the foundation will add forces at the spot of the deformity. This decreases the blocks ability to absorb compression.

2. The material on top of the blocks is inadequate. It should have been wide enough to cover the entire top surface of the block, spreading the weight and downward compression over all the bearing walls of the block. From the photo, it appears the weight was concentrated only on the interior wall.

Using heavy wood cribbing would be a much better choice for this job.

Anyhow, thanks for the post. It is a good learning experience for all of us.

Re: What not to do with a concrete block

Sat Aug 01, 2009 9:27 am

1. the blocks must have a solid and flat spot for the bottom. Any deformities in the foundation will add forces at the spot of the deformity. This decreases the blocks ability to absorb compression.

2. The material on top of the blocks is inadequate. It should have been wide enough to cover the entire top surface of the block, spreading the weight and downward compression over all the bearing walls of the block. From the photo, it appears the weight was concentrated only on the interior wall.

Using heavy wood cribbing would be a much better choice for this job.


I violated all three! The blocks sat on the steel tracks, small top wood blocks, and I had some 8X8 wood blocks but was in a hurry and I did not feel like finding the blocks. The concrete blocks were handy. I know better but took a shortcut.

Re: What not to do with a concrete block

Wed Aug 05, 2009 8:08 am

just another note the reason to use heavy timber cribbing is the timber will crush before it fails.

Re: What not to do with a concrete block

Fri Jan 22, 2010 9:29 pm

Here is a common sense thought about supporting whatever it is you are going to work on, be it farm tractor, truck , car, or whatever. If you cannot afford to either purchase the proper jack stands, or in the absence of that, construct substantial jack stands from steel of good design, then you really have no business attempting to repair, replace, or restore whatever you were going after. I understand not everyone is set well for tools, but if this is going to be your pass time, you need to invest the money for the tools and equipment to do the job safely, if you cannot do that, then you might have picked a hobby that will maim or kill you in the end! :shock: