Interior French Drain System
My Basement Flooded!
Water Drainage issues for basements is a very common problem and MUST BE addressed before investing thousands $$ into finishing and adding a basement bathroom!
Common reasons for a leaking basement:
Gutters missing or leaking on home
Improper or clogged outside drainage system
Lack of Drainage system to begin with (common for old homes)
No slope of grade away from home
Springs in yard
Heavy snow fall and thawing
Regardless of reasoning, once water has found a way in....It will always come in
Even if you excavated outside & added a whole new drainage system, chances are water would still find its way in!
That's why an Interior French Drain System is my go-to way of solving a leaking basement issue
Use a concrete saw to cut concrete floor
12-18" away from foundation wall is ideal
Using the Hydro-Tail water spray system will keep the dust down 👍
Renting or Buying an Electric Jack Hammer is the most efficient way to bust up concrete and remove
It important to dig down to below the footer level
Most likely all the water is coming in where the concrete block is meeting the footer
Digging below will ensure all leaking water will escape into French Drain System
It's amazing how much water continued pour in while I trenched this area!
Check out this Material & Tool Spreadsheet for all products used
Digging for the Sump Pump Pit is the toughest part of this interior French drain system
You want to dig down far enough to have the top of pit just below the existing concrete floor level
I'm using a 18" x 22" Sump Pump Basin
Where you decide to take the discharge hose and remove water is up to you
Most cities and municipalities do not allow ground water to be pumped into sewer system
If you drill a hole through foundation to discharge water, be sure to do it above ground level
You don't want another area for water to come in
For drilling hole I used my Hilti Hammer Drill with 2" bit
If there is a lot of ground water in hole dug, don't hesitate to drill holes around sides of basin
Allow water to enter pit so that the pump can remove it 👍
Be sure to purchase a check valve for this system
This valve will keep water from flowing back into pit
If you buy a corrugated discharge hose, they sell a special check valve that allows for easy connection
There are many choices when it comes to sump pumps
I like the Zoeller 1/2 HP Sump Pump for a system like this
Don't forget the Sump Pump Basin Lid 👍
Check out this Material & Tool Spreadsheet for all products used
The key component to this system is installing the actual drainage pipe
I am using a 4" drainage pipe with sock
If you can't find one with the sock, you can buy a drain sleeve to cover any kind of pipe
Ideally drain pipe should be even or below the footer
In this scenario I was even with the footer
Use small aggregate rock to fill around and on top of drainage pipe
If you have trouble digging down to get a 4" pipe below grade, consider buying a 3" drainage pipe 👍
Cut a hole into basin to add drainage pipe
I used a 4 1/2" hole saw for this 4" drainage pipe
Using a wall membrane after drainage pipe and gravel is set is super important!
You need to maintain a separation between wall and concrete floor to ensure all water goes into the French drain system
Using a wall membrane like the Delta-MS is perfect for this
There is a pre-bent plastic channel that can be used too
I found it to be way too expensive 😄
Cutting down the dimple mat isn't too tough and saves $400!
In this scenario I had to remove a some of the spray foam insulation off of wall
If you only have a block wall, you could run the entire sheet of membrane up wall without having to cut it 👍
Before running mat up the wall, be sure to drill holes in block wall to relieve any water that may collect in block wal
I'd recommend drilling every cavity of block wall (every 8")
I'm using a Hilti Hammer drill with 1/2" bit
Bend and run mat up the wall
Secure with concrete screws
If you are mixing concrete by hand, a bucket mortar mixer is a must-have 👍
Tool concrete flush with existing concrete with a mag float
Be sure to check out my Basement Bathroom Course
I’ve included this tutorial in the curriculum
If you have any questions about your own bathroom or basement project I’m more than happy to help answers within the course or coaching call
If this tutorial & course has helped you out, please share a review 😊