Which light wells in case of potential backlogged seepage water?

We have poorly percolating soil. Therefore, we need to procure suitable material for backfilling the working area around the basement. We have 2 basement windows that are to receive a light well. We are building with a white tank. The general contractor wants to sell us water pressure-resistant concrete shafts for €1500 each. Is there anything else? Do we absolutely need water pressure-resistant light wells? For these 2 basement rooms, we do not necessarily need light. But how to ventilate if we possibly omit the windows entirely?

Hi,

your GU must really like you, right? First the heating and now this?

Ok, the GU can’t do anything about the floor.

We also have a WU basement that needs to be protected against occasionally accumulating seepage water. The plan was only up to about the height of the basement windows but it has now also turned out that a terrain-level design water level must be applied.

In other words, water level = turf

We have 6 basement windows and there were three possible solutions:

1. pressure-tight light shafts as well as drainage pipes from the light shafts into a pumping shaft with a backwater valve and from there using natural slope to the planned inspection shaft. Cost just under €10k

2. like above, but without pressure-tight execution of the six light shafts. It must then be accepted that in the extreme case water can penetrate into these light shafts between the light shafts and the outer wall. This penetrating water would be drained via the drainage pipes and the pumping shaft, but slight moisture and dirt marks could still form in the light shaft area, which would have to be tolerated. Cost just under €5,500

So €4,500 for 6 pressure-tight light shafts, that’s €750 each.

3. Pressure-tight light shafts without bottom drainage but with glass cover on top so that no rainwater penetrates. Cost €5,400, that’s €900 each.

I consider €1,500 for one shaft expensive. Unless it includes a flood-proof basement window. That alone quickly costs €600-800. They are recommended anyway and we had planned for them from the start.

I would only leave out basement windows completely if you also have ventilation in the basement. Otherwise, sooner or later you’ll have rot in the place.

Best regards,

Andreas

Hello Andreas. The construction company responds tersely: "if there are no windows, there is no ventilation, or a forced ventilation must be installed, which has to be led up to the roof! if normal light wells are installed, the high-quality execution of the white tank is omitted" At the price of €1500, no sealed window is included, only the concrete shaft.

Hi Cumpa,

you wrote in your other thread that you already have a controlled residential ventilation system installed. The basement rooms should actually be connected to it as well.... and even if not, connecting them shouldn't cost a fortune. If the basement windows and light wells are removed, the general contractor should also credit you for that.

Best regards,

Andreas

Yes, we have controlled residential ventilation but decentralized. In the basement only in the guest shower and guest room.

I have to correct myself. The watertight concrete shafts cost €1150