Challenges with digging a basement

[Sixtens]

Hello good people,

I have dug out my basement down to the underside of the foundation, and now that the snow has started melting, I'm getting water in the basement. Under the foundation and throughout the basement, the ground consists of clay.

My plan for the construction is as follows:

• Geotextile directly on the clay
• 4–8 mm gravel as a leveling layer, about 2 cm
• 10 cm Isodrän
• Aging-resistant plastic
• 10 cm polystyrene

The idea is also:

1. To lay drainage pipes approximately 40 cm from the foundation and about 10 cm below the foundation's underside.
2. To achieve the correct slope, I need to cross the foundation twice with the drainage pipes.

Questions I'm considering:

• Is this construction reasonable and sustainable?
• Is it acceptable to cross the foundation with drainage pipes?
• Is there a risk of future settlements or other issues if I do so?
• How do you, with experience, view this setup

The picture was taken before the snowmelt.

 

[b8q]

Hope you mean that you will dig up and lay new drainage on the outside of the wall? That's where it does the most good.
Because if you mean that you will drain inside the basement and go under the foundation to get a slope, where do you then plan to connect the drainage?

 

[Sixtens]

Inside the basement, I plan to lay drainage pipes that cross the footing and then connect the drainage to an outdoor well, which in turn leads to a soakaway. What I'm most worried about is the water that comes in under the footing carrying material with it, which will pose a risk of settlement in the future.

 

[Jan_G]

You probably need to drain the house again and go down 40-50 cm below the foundation to remove the water. Don't let any water get under the house, just get rid of it ;-)

 

[Sixtens]

You probably need to drain the house and go down 40-50 cm below the foundation to remove the water. Don't let any water go under the house, just get rid of it ;-)

Just on the side where the water is seeping in, there's an extension to the house without a basement, and I can't access it for drainage from the outside.

 

[fribygg]

Just on the side where the water is seeping in, there is an extension on the house without a basement, and I cannot access it to drain from the outside.

Then you should drain to full depth around the extension.

 

[Sixtens]

Then you need to drain to the full depth around the extension

There it is drained to the bottom edge of the slab.

 

[fribygg]

There it is drained to the underside of the slab.

Then dig a foot deeper so you have the opportunity to remove the water from the basement.

 

[Sixtens]

Then dig a foot deeper so you have the opportunity to remove the water from the basement

It will be difficult, have a patio...

 

[cpalm]

Judging by foreign "construction programs," it seems that in some countries it is common practice to install drainage along the inside of the outer wall. I'm not going to comment on whether it's sensible or not.

The question is whether it's a problem at all in this case? I don't see any standing water in the pictures, but perhaps it has been worse?

 

[Sixtens]

Judging from foreign "construction programs," it seems that in some countries it is common to install drainage along the inside of the outer wall. Whether this is sensible or not, I will not comment on.

The question is whether it is a problem at all in this case? I don't see any standing water in the pictures, but maybe it has been worse?

I am more concerned about settlement damage, as the water that infiltrates can carry away material from under the footing and gradually weaken the load-bearing capacity.

 

[cpalm]

I'm more worried about settling damage

Aaa now I see the lake. Didn't show on the first picture(?)
Drainage on the inside doesn't prevent the flow. Rather the opposite.

 

[fribygg]

It will be difficult, have an altan…

Remove it.

 

[joakim_j]

What a deja vu, it looked exactly like that at my home too. I don't think there's any major danger of the walls being undermined, it's not like water is spraying directly.

 

[Sixtens]

What a déjà vu, it looked exactly like that at my place too. I don't think there's a major risk of the walls being undermined, it's not like water is gushing out directly.

How did you solve the problem Joakim? Sump pit?