Drainage Problem
Drainage Problem
(OP)
Hi all,
I have a drainage issue with my townhouse and I am in a dire need of a solution. There is an area in between my home and the next home that is pretty flat, about 30 feet long and 11 feet wide in between the houses. During the rains, most of the water pools next to my wall, so there is a slight slope towards my house. I attached pictures of the area from multiple angles.
The house does not have a basement and is slab-on-grade. The wall in question is the wall of the garage, and I can see efflorescence on the cinder block next to the wall on the inside. Somebody suggested a french drain dug 12 inches wide and 12 inches deep and only 12 inches from the foundation of the home, which would also be re-graded towards the french drain.
My concern is that 12 inches is too close from the house and that there is not enough slope in the area (which is pretty flat) to drain it to daylight. Do you think it is too close? What would the minimum slope be over 30 feet of french drain to make it work?
Any suggestions or alternative solutions will be greatly appreciated.
Thank you!





I have a drainage issue with my townhouse and I am in a dire need of a solution. There is an area in between my home and the next home that is pretty flat, about 30 feet long and 11 feet wide in between the houses. During the rains, most of the water pools next to my wall, so there is a slight slope towards my house. I attached pictures of the area from multiple angles.
The house does not have a basement and is slab-on-grade. The wall in question is the wall of the garage, and I can see efflorescence on the cinder block next to the wall on the inside. Somebody suggested a french drain dug 12 inches wide and 12 inches deep and only 12 inches from the foundation of the home, which would also be re-graded towards the french drain.
My concern is that 12 inches is too close from the house and that there is not enough slope in the area (which is pretty flat) to drain it to daylight. Do you think it is too close? What would the minimum slope be over 30 feet of french drain to make it work?
Any suggestions or alternative solutions will be greatly appreciated.
Thank you!










RE: Drainage Problem
RE: Drainage Problem
I have discussed a treatment of soil areas to waterproof them ,but it may not fix the problem of water entering the walls from outside.
Do a search on this room forum for the key word "bentonite" and my handle as the writer. You will see several of my comments on this method.
RE: Drainage Problem
Making sure your and your neighbor's gutters are both piped to the curb would help as well.
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: Drainage Problem
Some grading will definitely be done, but I am struggling with the decision if to put in the french drain or not, as most of the contractors are recommending it. It seems that it might be able to drain to the front of the house, but will be pretty shallow at only 12 inches deep. How close from the wall can it be installed? Is 12 inches too close if I decide to go with it? There is no basement, house is slab on grade.
RE: Drainage Problem
Also as mentioned prior, get the roof gutters into the road gutter directly.
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: Drainage Problem
If so, maybe try daylighting the roof leaders with some ADS flex pipe and see what that gets you before you pay for earthwork.
RE: Drainage Problem
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: Drainage Problem
RE: Drainage Problem
Why is the french drain the contractors go to fix for all drainage problems??
B+W Engineering and Design | Los Angeles Civil Engineer and Structural Engineer
http://civilengineer.la
RE: Drainage Problem
RE: Drainage Problem