Help, dampness in basement concrete, problem or not?

[arrowspark]

I was hoping that someone on this board is an expert on concrete and could answer a few questions I have about my basement. I bought a new house. The builder did not pour the basement slab all in one pour. They had not gotten around to installing the metal support beams when the cement people came to pour the basement so what they did was left open four square holes in the basement slab where the support beams would be. It rained during those days and I recall those holes filled to the rim with rainwater for a couple days. After the support beams were installed, they then went back and filled those holes the same day they did the garage floor slab, which was 6 days after the basement slab was poured. I do not know if they got rid of all the water in those holes before they filed . Now I am seeing what seems to be dark damp ring surrounding 3 of the 4 cold joints around the support beams.

Is was what the builder did out of the ordinary?
Is what I am seeing now a serious defect in the concrete that the builder should address? Or am I overreacting?

Is what I am seeing really moisture creeping up from underneath? If this isn't something serious, would some concrete sealers or some other product solve this?

Some Pictures:

Before Basement slab poured

After Basement slab poured

After Support Beams installed

Holes Filled

Cold Joint #1 Now

Cold Joint #2 Now

Cold Joint #3 Now

Cold Joint #4 now

 

[Sureshot]

How long ago?

Do you have a sump pump hole?

Have you run a dehumidifier?

 

[CNGsaves]

Welcome to GJ. Now would be good time to Update GJ Profile with Country / State / City.

Is this in America . . . where ?? What is local weather conditions / rain?? How is guttering / drainspouts from house working to get water away from the structure??

Best advice possible from GJer's with as much info possible. Good luck.

 

[ConCretin]

The construction sequence utilized by your builder isn't all that unusual. Slabs are often 'blocked out' to permit the future installation of columns. I can't say however that I've ever seen moisture manifest itself quite this way.

One thought is that the vapor barrier is not continuous through the block-outs - they probably cut it away when they formed the pockets for the columns. It sounds like you got some rain recently, which could have saturated the base material. This moisture could be wicking its way up. If this is the case, the problem might subside over time as the sub grade dries out.

The lack of a vapor barrier probably won't create major problems in the long term unless the soils under the home are naturally very wet. There are topical vapor barriers you can apply to the slab if it becomes a problem. I'd definitely address the issue if you intend to apply a floor covering of finish the space.

 

[arrowspark]

Sorry for the lack of info. The house is in Clarksburg MD. The basement slabs photos were from July 2013. The photos for the damp rings were taken yesterday. This is a new house, I have not gone through settlement yet. The sump pump is actually right next to the joint that looks dry. I have not noticed significant differences in the appearance of the damp spots after a rain. When I took those photos it had not rained in a few days.

 

[Sureshot]

My house is a split level from the 70's and the crawl space floor is 1 1/2" lower than the "basement" floor. The house never had a sump hole when we bought in '97 but I added one as our water table seems to be rising and we have had some real wet years. No flooding in our house but a a lot of water around.

The first place we see water is coming up around the footing in the lower crawlspace similar to yours only it is water not just damp. Except in real heavy moisture conditions the sump hole(at the other end of the house) will keep ahead of it and will draw the water back down beside the footing as it catches up.

If I were you I would get a good dehumidifier that pumps out or sits by the drain. You will have plenty of humidity anyway. I would monitor the water level in the sump and get a feel for the level vs floor look so you know over time how things are going. Even with the dehumidifier going to the drain I would first put it to a pail so you can see how much you are getting in a day or whatever period you choose.

I would wait to finish the floor until you see how things go.

Also be sure you have good drainage away from the house. I could take days for the water to get under right now but in excessively wet conditions could get worse with no time to dry or reach saturation.

 

[pauls340]

Based on averages of water/ cement ratio your Batch Plant puts about 32 gallons of water in a yard of concrete which covers 81 sqft @ 4" thick. Your concrete needs about 15 gallons of water to make the concrete, leaving about 17 gallons of free water that has to come out of your slab. This free water causes many problems in our concrete. It's not easy to see but if the moisture barrier was cut out of those infills, you could have wicking or moisture drive for many years. I would, find the Vapor Lock distributor in your area and spray a couple of thin coats over those areas, for that matter, over the complete slab, broom it in and then not worry about moisture drive in your slab....good luck