Are butt joints in ready-mix concrete basements acceptable?

Okay, I am not familiar with the walls being concreted together with the ceiling like that, but if nothing cracks due to the increased concrete pressure below, then everything is fine.

I don’t know how they did it, I don’t remember the construction exactly anymore. It could also be that they filled the walls first, which would make sense.
When I was on the construction site, they were still waiting for the concrete pump. If it hadn’t been delayed, I probably wouldn’t have made it to the basement in time and wouldn’t have seen the crack unfilled.

Load case "temporarily accumulating seepage water"

Word for word: ... In the earth-contacting area, the joints receive a sealing against "ground moisture and freely draining water" according to exposure class 2 of the WU guideline 2017...

Maybe one could still consider sealing the joints explicitly from the outside.

From the outside? Unfortunately, it’s too late for that. I believe the insulation was already applied at the factory.

Do you have an excerpt from the contract specifying exactly what is owed?

In summary:
- 20 cm, doubly reinforced base slab, max. 14 kg/m² steel content, more according to statics with extra charge – for us it was 144 kg additional steel in the base slab.
- 24 cm exterior wall, reinforcement according to statics
- 19 cm ceiling, max. 14 kg/m² steel, smooth steel formwork underside.
- Sealing as described above

Find yourself a competent construction supervision; that is a worthwhile investment.

Do you think it’s still worth getting an expert for the basement acceptance? You don’t really see much on site anymore, right? The photo documentation would almost be more interesting there.
And the ~500 € might be better invested in an acceptance planned in advance later in the construction progress?
I assume that the most important things with the concreting and the insulation are no longer visible now.

Heights and dimensions generally match very closely, measured by the main contractor’s site manager. I measured the base slab formwork myself before concreting, it was exactly right.
Since the recent horror scenario here was the “base slab in wrong size” topic.

Attached are a few impressions, unfortunately a bit mixed up when uploading.

1-2 before concreting
3-4 ceiling crack filled
5 wall joint filled
6 ceiling - wall transition
7-8 ceiling crack
9 wall joint
10 outside after concreting

[ATTACH alt="20201026_150313 (2).jpg" type="full"]52980[/ATTACH][ATTACH alt="20201026_153124 (2).jpg" type="full"]52981[/ATTACH][ATTACH alt="20201028_131147.jpg" type="full"]52982[/ATTACH][ATTACH alt="20201028_131220.jpg" type="full"]52983[/ATTACH][ATTACH alt="20201028_131255_LI.jpg" type="full"]52984[/ATTACH][ATTACH alt="20201028_134844.jpg" type="full"]52985[/ATTACH][ATTACH alt="20201028_135112.jpg" type="full"]52986[/ATTACH][ATTACH alt="20201028_135238.jpg" type="full"]52987[/ATTACH][ATTACH alt="20201028_135248.jpg" type="full"]52988[/ATTACH][ATTACH alt="20201028_140837 (2).jpg" type="full"]52989[/ATTACH]

PS: If I upload more pictures, the topic will soon need to move to the house pictures thread

Here are a few impressions, unfortunately a bit mixed up while uploading.

I know some people who are a bit strange, and sometimes even myself (so they say), but to black out the advertising on a folding rule? - no, really?

I know some people who are a bit weird, and sometimes I am too (so they say), but blackening out the advertising print on a folding ruler? - no, right?

Why not? That way no one can complain. Besides, it's bleached. I can gladly give you the company name via private message, if you like it so much that you want one too. Oh no wait... just checked: private message doesn't work.

Hi,

I think we can first take away your worries. It is important that drainage mats/dimple boards are then laid against the insulation on the exterior during construction so that the water can drain freely. With your cattle drainage, not much should happen anymore.

In my opinion, the filled cracks are not a problem; the system can handle that.
Side note: Ceiling span direction – with one-sided tensioned ceiling panels, the load is transferred in the direction of the nearest walls, usually in rectangular floor plans. The other direction has no structural bearing effect but only a constructive one (deflection, cracks, etc.). Therefore, a crack against the load-bearing direction is tolerable.

Regarding the joints, not much can be said at first, but the described load case is the lowest you can have. The only question would be whether the choice of load case is realistic, but if the groundwater is far away and the seepage water is well discharged, I think that can be correct.

Otherwise, the picture from the inside makes a good impression. The panel at the top looks a bit rough, but that is because the foil was laid in the fresh state, which is absolutely correct regarding curing. If you wait longer with the foil, early shrinkage cracks can occur; on the other hand, the foil does not damage the surface.

Therefore, I would not have an expert acceptance inspection here now, as they really cannot say much about it. A photo documentation, if you get one, is of course always good in the later process, should water enter. Furthermore, according to the Building Code, you are entitled to a 5-year warranty anyway (unless the VOB was contractually agreed).

If you have questions later on (including interior finishing etc.), feel free to contact me.

Best regards, Jann

Thank you very much for your very helpful assessment! Fast, friendly, competent help from an expert - people like you are a real asset to the forum!

Then I will now rather look for a place to have an expert acceptance done during the further construction progress.

A soakaway trench is installed at the street, I also hope that nothing will be missing there. Otherwise... it is a utility cellar.

Thanks to everyone and regards

King Julien

Where do you live?

Of course, you can always contact Dekra. They are also accompanying us with my current specialist, so in the end there are fewer discussions with the client during the acceptance.

Moreover, I would not focus only on acceptance monitoring but arrange for construction supervision. Most things are no longer traceable during acceptance.

Important things include the rough installation of plumbing & electrical before the screed is laid or before closing the drywall, as well as checking the proper sealing in the bathrooms.

I think about 4 appointments during the construction phase make sense so that the inspector can also make an assessment for the acceptance. There are also independent site managers for this who compare the construction status with the contractual service etc.

But maybe you can also be accompanied remotely in this regard.

Best regards and thanks for the positive feedback,

Jann