interior french drain
#1
03-21-12, 03:20 AM
interior french drain
Hi everyone
My townhouse built in 1976, and I have an issue with my French drain .Last year I fixed a crack in my foundation, the contractor found out that my exterior French drain installed on top of the foundation footing. He advised to reinstall a new French drain besides the footing properly, and this come with very huge bill. Inside my home there is a sump pump made from cement and gravel and no pipes connected to it , it is always full of water and it seems working fine .I have no water leek, but there is an issue with smile. Some contractors said floor should be remove ,and French drain should been install .I got some cheaper offers for internal French drain ,and since I have to remove the floor any way it should be better for the pocket ,but I don’t know if this is good option or I will have lots of problems in the future .
Can someone please tell my which better internal or external French Drain please?
Thanks
My townhouse built in 1976, and I have an issue with my French drain .Last year I fixed a crack in my foundation, the contractor found out that my exterior French drain installed on top of the foundation footing. He advised to reinstall a new French drain besides the footing properly, and this come with very huge bill. Inside my home there is a sump pump made from cement and gravel and no pipes connected to it , it is always full of water and it seems working fine .I have no water leek, but there is an issue with smile. Some contractors said floor should be remove ,and French drain should been install .I got some cheaper offers for internal French drain ,and since I have to remove the floor any way it should be better for the pocket ,but I don’t know if this is good option or I will have lots of problems in the future .
Can someone please tell my which better internal or external French Drain please?
Thanks
#2
03-21-12, 03:37 PM
What I would tell any customers.........if the sump is gathering water and pumping it out, and you have no other basement water issues, leave everything alone, do nothing!!!!
90% of basement water problems can be reduced or solved by having a gutter/downspout system that gets water at least 6' away from the foundation, and grading that does the same thing.
90% of basement water problems can be reduced or solved by having a gutter/downspout system that gets water at least 6' away from the foundation, and grading that does the same thing.
#3
03-22-12, 09:29 AM
Member
ahmadwca -
Your existing exterior drain is not installed properly, but may be adequate enough depending the soil type and amount of drain. Obviously, it has been adequate since 1976, although the crack may have been related to excess water under the footings or saturated soil behind the wall. A proper exterior or interior drain tile system has the bottom of the tile at or slightly below the bottom of the footing with several inches of well draining sand/rock. Now, filter fabric is used before and sand/rock, pipe and backfill is put in the excavation.
Exterior and interior drain tile systems both have advantages depending on when it is put in. For an older, established home with landscaping, exterior is a mess and can be costly (digging up landscaping, soil, patios, sidewalks) and may not the continuous if you have an attached garage. Interior drain tile is used commonly used on intial construction and does a better job of controlling the water under the footing and the water and upward pressure under a basement slab. I had a builder friend that automatically put both interior and exterior systems also with weeps from block on every home(over 2500 homes), irregardless of the soil type at no extra cost because the initial cost was so low. - Never wanted and never got a call-back
The 6' downspout extension will not eliminate water, but is can reduce the amount of water inside the basement.
The above slab systems are not like a drain tile system because the are just costly systems to collect water that has already leaked in and do nothing to prevent cracks and structural damage.
Dick
Your existing exterior drain is not installed properly, but may be adequate enough depending the soil type and amount of drain. Obviously, it has been adequate since 1976, although the crack may have been related to excess water under the footings or saturated soil behind the wall. A proper exterior or interior drain tile system has the bottom of the tile at or slightly below the bottom of the footing with several inches of well draining sand/rock. Now, filter fabric is used before and sand/rock, pipe and backfill is put in the excavation.
Exterior and interior drain tile systems both have advantages depending on when it is put in. For an older, established home with landscaping, exterior is a mess and can be costly (digging up landscaping, soil, patios, sidewalks) and may not the continuous if you have an attached garage. Interior drain tile is used commonly used on intial construction and does a better job of controlling the water under the footing and the water and upward pressure under a basement slab. I had a builder friend that automatically put both interior and exterior systems also with weeps from block on every home(over 2500 homes), irregardless of the soil type at no extra cost because the initial cost was so low. - Never wanted and never got a call-back
The 6' downspout extension will not eliminate water, but is can reduce the amount of water inside the basement.
The above slab systems are not like a drain tile system because the are just costly systems to collect water that has already leaked in and do nothing to prevent cracks and structural damage.
Dick
#4
03-22-12, 03:35 PM
My suggestion is for existing homes, where it would be VERY expensive to change/repair what exists. There is more than one item needing checking/correcting. It fixes or reduces the problem is most(90%) cases, and will not require a second mortage.
#5
03-22-12, 05:31 PM
Member
I did say the 6' extension for gutter water may reduce the problems and I usually recommend more extension length (buried with a pop-up, if possible).
The problem with a 6' lengths is that the excavation limits may be greater than 6' on the surface, so water gets dumped into questionable uncompacted, soil, so it takes the path of least resistance, which is back to the wall and footing area.
The point on changing what exists is very good, especially about the total construction AND replacement cost in the end. That is why interior situations, especially with an unfinished or semi finished basement are cheaper in the end and can be controlled better.
I smell a contractor knowing there was a old crack and sees a chance for a new job during a slow period.
Dick
The problem with a 6' lengths is that the excavation limits may be greater than 6' on the surface, so water gets dumped into questionable uncompacted, soil, so it takes the path of least resistance, which is back to the wall and footing area.
The point on changing what exists is very good, especially about the total construction AND replacement cost in the end. That is why interior situations, especially with an unfinished or semi finished basement are cheaper in the end and can be controlled better.
I smell a contractor knowing there was a old crack and sees a chance for a new job during a slow period.
Dick
