In the words of Kipling, an offensive effluvia has been noted in our entrance hall.
There was a slight back up when I lifted the manhole covers but no real blockage. Anyway, after rodding and flushing I had a peer around with a mirror on a stick and a torch. Two points of interest for which comments and advice are sought....
Where the new soil pipe for our extension is coupled in to an existing manhole there is a gap in the haunching which might allow backed up dirty water to leak into the trench and seep through the pea shingle back under the house. I have plenty of soft sand and masonry cement to hand but is there a special mix for the job?
The second issue is that, for reasons only known to the drainage contractor in 1975, our soil pipe starts as 6" salt glaze, travels round the side of the house (90 degree bend with inspection pit) reaches a second pit still in 6" and then reduces to 4" plastic! Not only is there ponding at the reducer but the pipe used has a spiral scroll inside; surely not intended for this use.
The cure must be to *up it* and re-do. Not easy as it is about 3'6" down in a tarmacced yard. But, does anyone know why this reducer was used?
regards