I've had three contractors come out to see the situation with my home. Basically, one side of the home sits below grade by about 20" and there is moisture getting into the outside wall and inside on the concrete floor. All agree the pitch of my land and the location on a hill with a road above all work to make my foundation under major attach by the "hydrostatic pressure" of the water.

Two want to install french drains inside under the concrete floor around the inside wall(s). This will involve major destruction to the inside walls up some 24" so they can get their tools in at an angle.

One says to do it from the outside along the foundation/footer wall. Digging down and out some 12 - 16" to install the perforated PVC pipe and crushed stone.

All will feed the water to a buried container/tank. The two inside guys will also need a sump pump to get it outside.

I'm confused as to which way is the best way. My thinking is it makes more sense to get the water away from the house before it gets inside. Is this way not keeping water sitting in that pipe and stone for days on end until it all flushes out or drains away? Keeping the humidity that much higher in the house.

In fact, I'm at a loss as to why the outside guy wants to dig up against the foundation in the first place. Is it not better to try and catch the water before it gets any where near the foundation and direct it away? Perhaps by installing the french drain two or three feet out from the foundation?

Any help and advice from someone who does this will be appreciated.

 

I think you'll find most here will advise to do it from the outside. By the time water reaches an inside French drain it has already entered your wall and traveled through it. This is not good for the wall and leads to water vapor moving from the wall into your house.

Excavating against the wall would give you the opportunity to have a waterproofing membrane and drainage mat installed against your outside wall, providing an additional layer of protection from water intrusion.

 

I'm all for keeping it away from the wall on the outside in the first place.

Nothing more you can do with grading?

 

Nothing more you can do with grading?

Grading has to be done either way. I will take some pictures to better aid everyone to see what I'm dealing with.

Please stay tuned and check back tomorrow.

Thanks!

 

I have both. My house was built with exterior foundation drains. Unfortunately, during extremely wet periods the water table is so high that they have nowhere to drain. After years of a wet, and occasionally flooded basement, I put in interior drains and an additional sump pump. My basement hasn't flooded since and I seldom (every couple of years maybe) get any water at all.

If your problem is a high water table it's gonna' come up under your house whatever you do. The interior drain will allow you to deal with it. If your problem is grading then foundation drains and gutter drains will probably fix the problem.

I don't understand about cutting the walls though. The guy that did the install cut trenches inside the footer all the way around, installed screened drain pipes to the sump and backfilled with peastone. An advantage of interior drains is that if they clog you have some ability to clear them.

 

This picture shows the slope of the ground fairly accurately. There is a crown in the center. It dips almost to a gully or swale on the right and towards the house on the left.


Taken from street level (the house is on a corner and on a hill) you can see I am dealing with run off from the street to some extent as there are no curbs to "guide" the water when it rains or the snow melts.


This picture shows the area where the the encroachment seems to be the worst. You can see the paint is pealing off the stucco from moisture getting in to the walls, which are cinder block under that stucco. The floor inside this area is about 18" lower than the ground outside.


This shot is a bit exaggerated by the position of the camera but it does show the angle of the ground is more toward the house than away from it.

From these pictures I hope I can get some guidance on exactly how to proceed with the repair. Please give me specifics. If you talk about using some kind of pipe or fabric give me brands and type so I can seek out this material. If I am to dig a trench tell me where, how deep and how far out.

 

Just a quick comment on the grading, since I live in frost country as well. But, during the winter the ground next to the house will see very little frost, if any, but 4 or 5 feet out it can lift as much as half a foot. Maybe less in CT, but it can lift. You need to add that estimated amount to your grading so that even with the frost lift the water will still drain away. A 2" slope out to 6' won't do it.

Bud

 

Am I not seeing gutters? xxxxxxxxxxxx

 

Grading, gutters and downspout extensions all seem to be needed here.

 

"Grading, gutters and downspout extensions all seem to be needed here"

Yes, all on my To-Do list. This will all help but will not be enough IMHO.

I have spoken to the town's maintenance super and he will have someone come out to see about what can be done about keeping the water on the road from entering my property. I am asking that I be allowed to deposit the dirt I will remove up on that hill in the picture to create more of a crown.

My plan in terms of the french drain is to install one in the area of the swale extending along that rock wall. The gutters I will install on the singled portion of the roof will also feed into this drain. This will take most of the water coming on to the property from above that might potentially reach the foundation/wall. This will run off to the rear side of the property.

A second french drain will be installed along the foundation in the area seen in the pictures. This will take care of any water reaching the foundation. This will connect to that same run off in a Y.

Comments, suggestions?