OK house is in Bangsarey its 6 years old and over last year we have had a continuing bad smell in one bathroom , its on ground floor but the kitchen and other bathroom are not affected , They are not on same Cesspit tank.
We have checked the U bend S bends toilet seal and shower trap all are good no pipes are blocked, chemical have been applied and cesstank emptied and inspected it seems OK .
Its getting worse and its dangerous , methane and drain smells make our master bedroom unusable and potential for explosion and health issues now high.
Im running out of ideas ,,, any suggestions or a good reference for a company to call in ??? area is bang sarey /pattaya