Back in August I asked this quesiton of the group. I thought I'd pass on
what we believe to be the answer.
> A friend called the other day and asked if I would take a look at his garage
> foundation. It appears as though several of the cement blocks has "rotted"
> away.
>
> Starting at the corner of the garage and working horizontally there is
> [suppose to be] a half block and then a full block, then the apron for the
> garage door. The garage wall sits on top of these blocks. However, the bottom
> half of each block is "missing", as though it had rotted away. Digging down
> where the block is suppose to be, I expected to find either another block or
> more likely a concrete footing on which the block had been set, but I found
> neither - just ordinary soil. Needless to say this seemed strange - what was
> suppose to hold that corner of the garage up?
>
> The block that is on the corner seems to be solid, but if we go around the
> corner and start working our way towards the back of the garage, the next
> block looks like it is starting to get a hole in it - again like it "rotting"
> away. The rest of the blocks look good.
>
> Pictures may be worth a thousand words
>
> www.visi.com/~arvidj/images/hole_1.jpg
>
> www.visi.com/~arvidj/images/hole_2.jpg
>
> If you tap on the garage floor in the corner you can hear it change from a
> "solid" sound to a "hollow" sound.
>
> So the questions are (1) what might cause the block to "rot" away? and (2)
> what should he do about it?
A cement contractor stopped by and assessed the situation. He told us that he
has seen this situation several other times. He then showed us that the garage
floor was sloped such that any liquids on the garage floor would run to the
corner of the garage that had the missing blocks. And his explanation is that
when the Minnesota road salt and snow melt off the car the liquid will run to
that
corner of the garage and them down the block. He suggests that over the years
the very salty water reacts with the cement in the block and causes them to
disintegrate.
Just though I'd pass on the best solution that we'd heard to "Where did the
blocks go?"
Arvid
|