Render and mortar in a damp cellar

[craig h]

The brick floored cellar of my turn of the century mid-terrace house suffers from damp, black mould on the lower third of the walls and a slight glisten on the floor. When we moved in last year it was crammed full of junk, floor to ceiling and enough to fill an 8-ton skip when removed! It has now had 10 months to 'breathe and dry out a bit and I am looking to improve the damp problem enough to be able to store tools etc down there, at the moment anything metal left out rusts. The neighbours tell me that about 3 years ago all the cellars in the street flooded during the building of a new school opposite which has obviously contributed to the problem. The brick walls were painted with a masonary paint that was soggy and I have scraped off and the front wall, which is stone, was rendered. That had also gone soggy and was easy to scrape away leaving the stone showing through.
The mortar between the bricks. in places, is the colour and consistancy of earth so I am keen to re-point the walls. Would normal mortar with a plasticiser added be adequate or is something more specialised required? Same with replacing the render, is normal cement render acceptable and should I add lime to the mix?. I am planning to paint all the walls with a specifically designed cellar paint when the walls are in a better shape. I 'm not looking to create a living space, I just need to do enough to make it a bit drier.

[thedoctor]

See our project on underground waterproofing