Help needed with a floor issue

[EddieWalker]

I started a job today for a client with a three year old vinyl floor that is buckling. Under the vinyl planks is engineered wood strips that are glued to the concrete slab. The wood is ten years old. She doesn't know what was on the floor before that. The house is 20 years old.

There is no damage or staining anywhere along the walls. The concrete is noticeable lighter and drier looking along the walls. The concrete is perfect. No cracking of any kind.

What is really weird is that the concrete is noticeably darker in a perfect square inside the room with a light area all around it, next to the walls. The damaged wood is where the dark concrete is, but no all of that area is damaged wood. The wood by the walls is perfect. Light in color, solid and no sign of mold. The damaged wood is covered in black and white mold. It's falling apart and it smells really bad of mold.

A plumber scoped the drain lines and pressure tested the water lines. He could find no sign of a leak. On the outside wall, the concrete slab is exposed for 4 to 6 inches. There is no sign of a leak or any sign of moisture. The wall with the bathroom has perfect wood flooring for about 2 feet, and for several feet before that, it was minimal coloring on the wood, but not dark and no mold.

The HVAC system is in the attic above this room. There is no sign of a leak along the walls. All sheetrock and baseboards are perfect. Not even a small crack at the seams.

The concrete is dry to the touch. The wood flooring is dry to the touch.

All ideas, thoughts and suggestions are appreciated. As of right now, nothing is too crazy!!!!

Thank you

 

[Topzide]

Put a sheet of clear plastic on the concrete to see if moisture forms between it and the concrete.

 

[t1kilo]

Agree with topzide. Sounds like missing moisture barrier below the slab.

 

[ponytug]

@EddieWalker that sure looks like the damage one gets from rising water vapor, either due to a high local water table, or poor site construction (missing, or poorly installed subsoil membrane, or a poor membrane) or poor site drainage. Given the dry walls, I would be inclined to the barrier being the issue.

Personally, I have seen interior drain systems and treatments, and I am not a fan, but sometimes I think it maybe a viable choice.

A couple of questions;
how is the drainage around the house?
How are the gutters drained?
Are there gardens or lawn up against the house?

If it were my property, I would invest in some serious perimeter drain and sealing, and ensure that the gutters drain into a system that takes the water a good distance away from the house, with a gravel bed with water barrier around the house. I would also use a permeable flooring material. I was part of a renovation of an existing building once, and my prime contractor more or less said "no way, no how" to using a sealed flooring material (epoxy) as he had seen it fail in other buildings nearby. I suspect when the other issues are addressed something other than plastic flooring is warranted.

All the best,

Peter

 

[anomad]

Does the house have a dehumidifier along with the regular HVAC? I had a similar issue in my basement that was solved by a simple portable dehumidifier running. It worked so good I got two more. Might be worth a test before extensive reconstruction.

That looks like condensation to me. Warm moist air finding a cooler surface to produce condensation. If it was water infiltration (above, below, around or through) I think you would have figured that out with a very cursory inspection.

Could the slab have been poured over an old well/root cellar/cistern that collects water and wasn't filled in properly? I'd slap a few dehumidifiers in there long before I dug all that up.

 

[QRTRHRS]

If you go the dehumidifier route add condensate pump(s) to dispose of the moisture if you have a drain line to hook up to.

 

[dodge man]

I’d say it’s moisture coming up through the concrete also. I’ve seen it a garage before and it can get real wet.

 

[anomad]

If you go the dehumidifier route add condensate pump(s) to dispose of the moisture if you have a drain line to hook up to.

I was hoping for a gravity drain... We don't have to explain that stuff to Eddie. LOL

 

[dstig1]

Put a sheet of clear plastic on the concrete to see if moisture forms between it and the concrete.

Beat me to it, but will add you should tape a square of heavy plastic down, not just lay it on top. Let it sit for a day and then peel it up and check. Maybe do it in a few places in the darker and lighter areas to compare.

Edit: vinyl is notorious in this situation as a major vapor barrier. Which leads back to the earlier point t1kilo and others made: lack of vapor barrier below the slab. So the vinyl acts as that vapor barrier in this case leading to bubbling and other moisture problems.