reinforce basement cement block wall with pinning
Dwayne
One side of my 8' block wall in my walk out basement has a long
horizontal crack that follows the grout line. The position of the
crack is above the bottom row of blocks (8'' from floor) above the
crack is a 1/4 overhang. Several contractors have been to my house and
they all have different approaches. However, one suggested pinnig the
wall - cutting away 1/2 a block about 3 blocks up from the crack every
3 feet and inserting rebar and hydrolic cement. I like this approach
since excavating would require moving power, condensing unit and would
tear up mine and my neighbor's yard. I'd like some advice/testamony
from someone who has done this or has had it done.
Note: I suspect the crack has resulted from a combination of repeated
heavy snows with a freeze - thaw and refreezing along with
consrtuction w/blasting going on about 75 yards from my house. I
noticed the crack the night after some heavy blasting but trying to
prove it...
Thanks for any advice.
Dwayne Brown
dbr...@phoenixcolor.com
Brad
dbr...@phoenixcolor.com said...
I would be sure about the cause first. If the ground is causing the
problem by freezing and expansion you can fill your basement solid with
concrete and it will still crack. Solve the problem, not the by-product.
Dwayne
>
> I would be sure about the cause first. If the ground is causing the
> problem by freezing and expansion you can fill your basement solid with
> concrete and it will still crack. Solve the problem, not the by-product.
Point well taken. I do intend to excavate and check drain tiles etc.
but I will not be able to do this for several months and I feel
uncomfortable leaving the wall as is for any length of time.
Thanks for your input.
Henry
> dbr...@phoenixcolor.com said...
> > Hi all,
> > One side of my 8' block wall in my walk out basement has a long
> > horizontal crack that follows the grout line. The position of the
> > crack is above the bottom row of blocks (8'' from floor) above the
> > crack is a 1/4 overhang. Several contractors have been to my house and
> > they all have different approaches. However, one suggested pinnig the
> > wall - cutting away 1/2 a block about 3 blocks up from the crack every
> > 3 feet and inserting rebar and hydrolic cement. I like this approach
> > since excavating would require moving power, condensing unit and would
> > tear up mine and my neighbor's yard. I'd like some advice/testamony
> > from someone who has done this or has had it done.
> >
> > Note: I suspect the crack has resulted from a combination of repeated
> > heavy snows with a freeze - thaw and refreezing along with
> > consrtuction w/blasting going on about 75 yards from my house. I
> > noticed the crack the night after some heavy blasting but trying to
> > prove it...
the hill where my house is built into.
I know all about pinning. I agree with pinning the wall as explained
above because I did it to my basement wall. Total length 54 feet!
I did this myself as follows.
Cut or smash out 3 horizontal blocks; Only the inside portion (the
basement side)and half the web so that outside of block remains
intact. Pour in very liquid mortar. This mortar is so liquid that I
can scoop it and it drains from the scoop into the cavity. It takes an
enourmous bit of mortar to fill 3 cavities 3 blocks wide and 5 or more
blocks high! When cavity is full, cement in 3 replacement blocks.
(replacement blocks are half width of smashed out blocks) Then wait
until cement is dry enough to start on next 3 blocks and repeat. Messy
and gruelling, but worth because the wall never moved an inch since.
Note that you can only take out 3 horizontal blocks at the time for
fear of buckling the wall!!
shawn
First fix the problem, then reinforce if nessary. To give you an
example I bought a distressed property where previous owners had tried
to reinforce a large elevated concrete deck. they did everything but
address the problem, so over the years the problem kept getting larger
until eventually the whole thing needed to be redone. I imagine they
had sunk *at least* 10 grand into it over the years and none of it
addressed the real problem, that being boatloads of rain water was
saturating and compacting the fill under the deck putting outward
pressure on the walls which were not meant to have wet fill (no
drainage holes, no gravel etc, etc). They did anchors, slab jacking
(because the water had compacted the fill several inches under the
deck), but not one of these 'professionals' addressed the fact that
1000+ sq feet of deck has to DRAIN (no deck drain) and not though the
CRACKS hidden under riverrock, imagine 1000sq/ft of 1-2+ inches of
rain everyday in summer in the south being funneled. They had even
patched previous repairs with a porous material that the water went
straight through.
You should research on retaining walls, hydrostatic pressure, drainage
grids, etc. First attempt to relieve the pressure, then reinforce if
needed...need to get the pressure off the wall.
-shawn