Water and probably mold problem on slab floor

[TDKPE]

The in-laws' summer ranch house up here is built on a slab which is unusual for up here.  It has a boiler and in-floor radiant heat, and the copper tubes in the floor are original from 1961.  The parquet floor tiles were lifting in a few areas of one room, with a big area noticeably broken free of its glue.  The hall outside that room also has an arched line of tiles from the room on the other side of the wall to the little closet where the manifold with the balancing valves is.

The heating system also has a leak, though I don't know where the water is going.  It takes a day or two to leak down from the 10 psi to where the system shuts down from low water if I leave the feed water valve closed.

I ripped up some of the parquet flooring, and found what I think is mold.  Some of the tiles actually had liquid water on the bottom of them.  The concrete is deteriorated is spots, being course white dust, and most of the mold seems to be around the walls, under the trim.  

The landscaping has always concerned me, as the grass is close to the siding, and in some areas slopes toward the house.  There also doesn't seem to be a clear way for the water to leave the yard, which slopes down to the street, but the back and side yards seem to be a little lower than at the front before the slope gets noticeable.  I took the outdoor pics today in the rain.  I can't imagine how much water there is with a downpour, though I was hoping for one so I could trace the drainage paths.

My in-laws want to sell this place as they're pushing 90 and can't drive up here again (and won't fly with the dog - don't ask
), but it's not saleable at this point with the floor ripped up and mold present.  I have ServePro coming tomorrow to take a look, but that makes it official and may even trigger state law about reporting mold.

I don't think the water in the yard gets high enough to leak in, but it may be possible the house slab is sitting on a giant puddle, with water wicking up through the concrete. 

If anyone has any comments, useful or otherwise, other than 'sucks to be you' (since it's true, and I know it), I'd like to hear them.  

   
Moldy (I think) slab

   
Moldy (I think) slab

   
Moldy (I think) slab

   
Wet underside of parquet tile

   
Wet underside of parquet tile

   
North-east corner looking east

   
North-east corner with puddle against foundation

   
North-east corner looking south toward street

   
Church property next door with some grass sloping toward the house.

[brianwelch]

Not to pile on, or be a harbinger of bad news, but those types of water under the concrete slab issues here in SE PA also result in termite problems...they apparently love the moist soils...

[Bill Bob]

Picture # 6 also shows water damage/decay on the siding.  Would a french drain be an option?
Bill

[TDKPE]

Would a french drain be an option?

Probably.  Or some grading, though there’s almost nothing that can be done with the grade due to the giant birch trees that are only 10 ft away.  

There is a wooden ‘deck’ of sorts, just laying on the ground outside that sliding door, under all those leaves, so that would have to be pulled up.  It might be possible to direct a drain to the east, behind the camera.  That ground slopes down a little away from the house, once you get far enough away from it.

[EightFingers]

Where is the mold in relation to the outside? Is the hydronic system still being used?

[Robert Adams]

Is that a horizontal board under the T111 siding? If so it's sitting in the dirt and way too low and wicking up water. You should have several inches of slab above ground level. There shouldn't be any wood anywhere near that close to the ground.

[Mr_Mike]

Sell it "as is" and run away. You probably have slab leaks. That will necessitate abandoning the in-floor heat and needing to add a furnace. No sense putting money into it as you can't break even. Let someone else think they are getting a deal on an easy flip.

[TDKPE]

Where is the mold in relation to the outside? Is the hydronic system still being used?

Yes, it's still in service.  I solicited three quote or replacement, all three sales guys suggested mini-split heat pump systems with five head units and two outdoor units, and only one has actually quoted.  Over $20k.  Lotta money for that little house.  

I pulled up more floor yesterday, and mold seems to be concentrated around the perimeter.  With the color of the flooring glue, it's hard to tell what's mold and what's just a change in color, but there is definitely black around the perimeter walls, including the inside walls between rooms.

Is that a horizontal board under the T111 siding? If so it's sitting in the dirt and way too low and wicking up water. You should have several inches of slab above ground level. There shouldn't be any wood anywhere near that close to the ground.

It's actually not in the dirt, but it's real close.  I need to rake those leaves away, of course.  And that's a real puddle at the corner with leaves floating on it; pictures don't really show how much water there is.  I know it's not good by a country mile, but with those two giant birch trees with leprosy that constantly rain body parts all over the roof and yard, digging that deeper is probably not an option unless it's a moat.

This is the same east side of the house (the side with the deck), but at the front.  There is a small amount of elevtation change over the length of that outside wall, as witnessed by the dirt being a little further from the siding than at the back, assuming the slab and siding bottom edge are level, but it ain't much.

   
The street is to the left, where the leader is pointed

[MstrCarpenter]

Tom; What is the heat source? The boiler could be leaking a little and evaporating as the heat and pressure increase. Leaks in the loops are bad! If the boiler is in good shape baseboard heat is an option, as well as an air handler in the attic. Hydronic air handlers are more common with the "A" coil too, so you could take advantage of energy savings down to about 40 degrees with a heat pump and have central air as a bonus 

 If you have standing water next to the concrete slab it will wick enough water to cause that amount of mold. Even if it's only seasonal, the spores will multiply every time they get moisture. My initial thoughts are that the grade has changed over time with the addition of mulch and growing trees (roots). The walls should be inspected for mold too. Pull some baseboards and cut out some drywall for an initial test. If the walls have sill-seal and the drywall doesn't touch the concrete, you may be in luck. If mold is confined to just under the flooring in limited areas it's not devastating. If you set up fans after you pulled up the flooring, Serv-Pro will have to clean everything in the house. Get tested to confirm all mold is removed before re-construction.

[Phil Thien]

Random thoughts...

Around all inside and outside wall perimeters seems like a lot of mold for a system that holds pressure for a day, the tubing would have had to fail at every turn, no?

Is it possible the floors were flooded at some point and what you're seeing is mold from that?

Is there similarly moisture in all the places you're finding mold? Can you apply clear plastic sheeting over the expose slab areas and pressurize the system and see if you get any moisture under the plastic?

Are there any zones you can disable or ways to separate rooms so things can be broken into smaller pieces for pressure testing?