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Posted: Thu Aug 29, 2013 6:53 pm
by r896neo
I recently built a small wall and 2 piers on a job. The walls were built of 7N concrete blocks and rendered with a scratch coat and float coat of render mixed 5:1.

The wall is 9 inch blockwork and the piers solid 18inch blockwork.

The footings were into decent ground but there was a layer of type 2 fill approx 18 inches deep so we went on down and a foot into original clay.

The paving falls away from the wall.

The wall is obviously sucking up moisture badly to the extent that its leaving tide marks on the render.

I am concerned that the render will be adversly affected in the long term.

Any thoughts or ideas on a solution? injected DPC?

Photos below

Image

Image

Posted: Thu Aug 29, 2013 9:03 pm
by montygti
You should never render right to the floor. Should have installed a render stop/drip bead leaving a gap to the floor. Also did you install a dpc on the wall? The only way i see of sorting the problem out would be cut the render off of the bottom, install a dpc in the wall and install a drip bead and render down to that. But someone will probably have a better solution.

Posted: Thu Aug 29, 2013 9:08 pm
by lutonlagerlout
is the paving/ground higher the other side?
are the copings pointed now?
did you use waterproofer in the scratch coat?

it looks tidy enough,If there is no possibility of water laying against it then i would leave alone
LLL

Posted: Thu Aug 29, 2013 11:14 pm
by r896neo
I asked the spread who i have worked with on loads of sites and he said not to bother with waterproofer in the scratch coat. In hindsight i should have insisted.

I have been involved with a fair amount of exterior blockwork walls done in this same manor before and never had this problem?

I know a dpc and stop bead is the pukka job but as above this is a pretty common method round these parts with no i'll effects.

In my current thinking cutting a line and putting in a stop short of the paving is not the issue so much as the volume of water suggests to me the actual block sucking up water.

These photo's were taken after 2 dry days

Posted: Fri Aug 30, 2013 12:58 am
by montygti
The problem with allowing this to happen if it is the block that is wicking up the water is when it freezes its likely to blow the render off of the wall. Whats behind the wall. Is soil higher than the path on the photo side.

Posted: Fri Aug 30, 2013 12:31 pm
by r896neo
no its just more paving but even lower and falling again away from the wall

Posted: Mon Sep 02, 2013 2:03 pm
by r896neo
Really sorry to bump but any more ideas or opinions welcome as I need to come up with a plan.

Posted: Mon Sep 02, 2013 4:35 pm
by lutonlagerlout
use a piece of 38mm batten as a profile and grind the render off the bottom
this may/may not help
LLL