Thanks for the reply.I have the rest of the basement unfinished. The basement floor is not wet anywhere. But if I keep a box or something directly on the floor and move it after a while, I am getting this mark on the floor. I am attaching some pics for you to look at. The house is sitting on a higher ground than the houses across the street. I doubt we have t a higher water table. I saw when they dug the basement. Pretty much dry land only. I personally saw the weeping tiles put in around the perimeters and connected to the sump pit. Now, is this black mold that I see when I move the boxes? I have never seen it in my previous basements.

The moisture drive through the floor is normal, though it could have been greatly reduced by a poly vapour barrier under the concrete. I used to lay tiles directly on basement concrete floors. But for the last 15 years have used an uncoupling membrane which will eliminate cracking and control minor moisture infiltration.

You have a two-year TARION warranty against water penetration. Notify TARION immediately before your time to file a claim runs out.

I dont know if that is mold or not. I know you said your dirt was dry during construction but I am wondering if the grade of the yard has changed since then. Maybe water is going towards the house or there are downspouts that put water at the edge of your house or worse putting water in your weeping system. Things to check on.

What I would do is after checking for proper water drainage away from the house, clean the floor and paint watertight on there. Latex or oil based depending on your plans, if you want max waterproofing then oil based, if you want to tile then use latex.

Latex Based Watertite

Oil Based Watertite

Thanks for the information "worthy". I am still under warranty. Just not sure how to prove the water penetration to the builder. I may have to bring in some professionals to test for moisture / water seepage.

The grading is a pretty visible slope towards the front of the house. However, the perimeter of the foundation is graded away from house as usual. Downspouts are extended away from the walls. I want to see how the basement will be holding up for this coming spring thaw. There is quite a bit of snow accumulated around the house.

My question is, how do I prove this is a water penetration to get my builder to fix it? If they are to fix it, what should they do? The tiled portion is only less than 50 sq ft. Obviously, that has to be ripped out I guess.

"Just not sure how to prove the water penetration to the builder. I may have to bring in some professionals to test for moisture / water seepage...what should they do?" said Joe from the Hammer.

You don't have to prove anything to the builder! Let alone hire outside professionals to buttress your case. Nor provide the builder with the fix. If you're unsatisfied with the builder's response, you must file a claim with TARION before your warranty expires. TARION inspects and decides. And even their initial decision can be appealed.

As well, if you start applying useless and counterproductive remedies, the builder will claim to TARION that you are causing the problem.

Builders depend on dragging such consumer complaints out past the deadline. Stop playing along.

I agree, make a claim about a wet basement slab and improper grade on the one side of the house. You would be surprised how just one side of the house with bad grade can cause problems.

I realize this thread is from a few years ago. But I was wondering if the OP figured out a solution. We are having the exact issue on our house which is a year old. And we have added it on our one year warranty list but no one seems to be able to tell us a solution and I really don’t want to be brushed off by the builder.