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?
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.
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.
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.
