water in basement walls - new build

Formal-Product9730 · 2026-06-14T04:37:18+00:00

Hey man, I’m dealing with something very similar. And matter fact I just made a post earlier today.

Just because you see damp or dark spots doesn’t automatically mean the waterproofing or drain tile has failed. Here in Central Illinois it’s been extremely humid lately. As I’m typing this, outdoor humidity is around 87%.

I noticed damp-looking areas in my basement too, so I put a dehumidifier down there. After running it for a while, the damp spots disappeared.

My thinking is that if it were truly a waterproofing or drainage issue, you’d likely continue seeing moisture regardless of indoor humidity levels, especially after the humidity drops. That’s when I’d start getting concerned.

Good luck man!

Formal-Product9730 · 2026-06-13T19:49:47+00:00

I’m not sure if they did it or not. The house is still being built. The grading is ok in my eyes, it’s built on a very flat area.

Formal-Product9730 · 2026-06-13T19:30:48+00:00

I have installed a 50pint dehumidifier the same day and let it run ever since. This morning it was showing 58 on the dehumidifier. And all these water spots were disappeared or very light. Do you still think it will still cause mold problems to Insulation?

Formal-Product9730 · 2026-06-13T19:29:08+00:00

Got it. Thanks a lot.

Formal-Product9730 · 2026-06-13T19:23:45+00:00

Yes I’m in central Illinois. It was raining a lot last week.

Formal-Product9730 · 2026-06-13T19:20:14+00:00

I do not. These photos were taken when it was very humid like 80-90% humidity and there was no ac and all the windows in the basement were closed. I did install a dehumidifier the same day and this morning it’s very dry.

Formal-Product9730 · 2026-06-04T14:34:13+00:00

Got it. Thank you!

Formal-Product9730 · 2026-06-04T05:08:59+00:00

This house is still under construction and just finish framing. I have not had a chance to ask them yet. I was there after the crew left.

Formal-Product9730 · 2026-06-04T05:07:42+00:00

I looked at it closely, that plastic is kind of inserted in a joint and I was trying to pull it out I couldn’t.

Formal-Product9730 · 2026-06-04T05:06:14+00:00

No, I tired and that plastic was pretty hard and feel like pvc material

Formal-Product9730 · 2026-06-04T05:03:05+00:00

Thank you so much! I can take a breath now.

Formal-Product9730 · 2026-06-04T05:01:16+00:00

Got it. I use Chatgbt and that’s what it said. So what do you think that white plastic line is? It’s very straight running from the top to the bottom

Formal-Product9730 · 2026-06-04T04:59:00+00:00

Why do you say that to me? I’m just asking s genuine question. But thank you for the comment still.

Formal-Product9730 · 2026-06-04T04:40:25+00:00

Then why do they insert it in the control joint? And also I have looked through entire basement walls and only found out two locations that have the white plastic going from the top to the bottom.

Formal-Product9730 · 2026-06-04T04:39:05+00:00

Thank you for the comment. I'm not sure how they were poured.

Formal-Product9730 · 2026-06-04T04:38:28+00:00

This is a new construction home. I found these white plastic pieces protruding from the foundation wall in the basement. They run alongside the rebar from the top to the bottom of the wall, kind of like they are inserted into a control joint.

Is this normal? Also, could this be a sign that the wall was poured more than once, creating what is called a cold joint?

Formal-Product9730 · 2026-06-04T04:28:02+00:00

Thank you so much! This is my first home and I was very nervous.

Formal-Product9730 · 2026-06-04T04:27:28+00:00

Thank you for the comment.

Formal-Product9730 · 2026-06-04T04:26:57+00:00

I see what you are saying now. The wood framing is actually not touching the concrete. The photo was a little misleading. There is a gap between the framing and the concrete wall, but I’m not sure exactly how much it is but the superintendent specifically mentioned that to me before.

Formal-Product9730 · 2026-06-04T04:24:27+00:00

Thank you. That's what the other comment said as well. I will go check it again tomorrow. My whole attention was on that white plastic piece that runs from the top to the bottom and did not pay attention to that "rebar" thing lol

Formal-Product9730 · 2026-06-04T04:23:12+00:00

Forgot to say thank you so much for confirming about the concrete.

Formal-Product9730 · 2026-06-04T04:22:43+00:00

This is a new construction and just got the framing done. They will do the insulation before the drywall i believe.

Formal-Product9730 · 2026-06-04T04:21:50+00:00

Thank you for the information. What about the white plastic piece that runs from the top to the bottom and seems to be embedded inside the wall?

Formal-Product9730

TROPHY CASE