ᐅ Light Well Drainage: Watertight Window or Pump?

Hello,

We have the following issue in our house:
Our builder originally neglected to provide natural drainage for the light wells.
As an alternative, we were offered either to install waterproof (pressure-resistant) windows or to have an inspection chamber including a pump installed in our front yard.
Due to a high groundwater level, water is currently being pushed into the light wells through their openings.

Is there a system that prevents water from entering from below but still allows rainwater entering the light well from above to drain properly?
Would you rather have a waterproof window installed or a pump?

Good luck

Classic planning mistake. What are basement windows doing in the air shaft within the groundwater zone?

Drainage beneath the air shaft is the only sensible solution. It should be retrofitted.

How is the basement designed to resist hydrostatic pressure?

We had the same problem with our old house.
After several attempts, the following approach proved effective.
Cover the light well with a glass pane,
seal the bottom of the light well,
bury a vertical 40cm (16 inch) drainage pipe along the outside of the basement wall down to the basement floor,
pour some concrete at the bottom, place a cover on top in the garden,
install a submersible pump connected to the drainage system leading into the cistern.
Some years nothing happens,
in wet years the pump runs 1-2 times per hour for about 10 minutes each time.

Grauer Hase schrieb:

Either watertight windows

Depending on the amount of water pressure, you end up with more or less full aquariums that don’t drain quickly. And a tilted watertight window can still let water in.

Grauer Hase schrieb:

Inspection shaft including pump

That’s more likely, but depending on the conditions, it can be a complicated undertaking. The area around the house has to be excavated, and somewhere in the garden an inspection shaft must be installed. From our neighbor’s experience, costs can quickly reach five figures.

Grauer Hase schrieb:

Is there a system that doesn’t allow water in from below but still drains rainwater entering the light well from above?

That’s hardly possible. Either you have fully watertight light wells with no drains and a glass cover on the grate, or you have standard light wells with drains and no glass cover.

Grauer Hase schrieb:

Would you rather install a watertight window or a pump?

First, you need to clarify whether you are currently dealing with perched water that cannot infiltrate or groundwater. The first is temporary, the latter permanent. According to our soil report, we have the first case and the following solution: All light wells are not watertight, and all drains are connected with a 0.5% slope. A core drilling was made under the last light well, and the drainage pipe runs into the house. Inside, the water flows into a small lifting station (Homa Sanibroy). Outside, the terrain is shaped so that all garden areas around the house slope slightly away from the building.
With this solution, you save the inspection shaft and expensive equipment that requires frequent maintenance. However, this solution should only be used if the areas to be drained are less than 5m² (54 sq ft).

If you have to constantly fight against groundwater, then definitely install watertight light wells (and standard basement windows).