Basement Floor Tile Problem: VCT Preferable to Marmoleum or ...?

[Jonathan S.]

The thread title sort of sums up the question, but maybe this is a situation where formulating the right question is more important than the answer to any particular question?

The quick problem is that we have some moisture damage to some floor tiles in our finished basement.

Providing a super-quick summary is probably impossible, so here's the full version:

1. House was completed in February 2006.
2. Basement has four rooms (although the doors between them are almost always open). Two are essentially unfinished (one is furnace and ancillary ski storage, one is billiards / table tennis table and more storage), one is my ski shop/workroom w/ VCT tile, one is rec room & bouldering wall with marmoleum tile.
3. In 2006, we had a minor water leak, which turned out to be some inadequately plugged concrete foundation holes.
4. In 2007, we had two major basement floods as a result of poorly designed backyard grading.
5. After that, all was fine. Except once, maybe around ... 2009? ... 2010? ... I put down an exercise mat on the marmoleum tile for a few months, and kind of forgot about it (since we had an identical mat upstairs). When I eventually moved it, the tile looked kind of . . . blackish.
6. During this winter, a small plastic bin (about two square feet on the bottom) containing a gift of some toy blocks and such was placed in the middle of the rec room. When I eventually conceded late this spring that ski season was indeed winding down and started putting things away, I noticed that the marmoleum tile underneath that bin was buckling up, etc.
7. The developer checked out the basement with a moisture sensor, and doesn't see any signs of water coming in from the walls. (This went on and off -- mainly off -- for about a month or so...)
8. The climbing wall pads that have been on the marmoleum floor for . . . years, are covered up some water damage to the tiles, but no buckling. (The rec room doesn't get used too much other than for the exercise bikes, since our toddler daughter is still a bit too young for such a non-toddler-proofed area, and she loves climbing *everything* *except* the climbing wall -- although visiting older kids absolutely love the room.)
9. The VCT tiles in the adjacent ski room are all structurally sound, although if you look carefully at the seams, they could be showing some moisture seeping between them.
10. The developer concluded yesterday (Monday) afternoon that the problem is the choice of marmoleum tile for the rec room, instead of just using the same VCT tile as in the ski room. (This choice was made by the owner of the company, who tragically died relatively young a couple years ago, so no way to question the detailed rationale, or lack thereof.)
11. My wife talked with three basement specialists today (Tuesday), and they're all coming by (separately!) tomorrow (Wednesday). One didn't sound very reassuring. (Might have even been drunk -- why are we letting this guy into our house?) One was very brief. The other provided lots of feedback, and advised that we should ask the developer (whom I just emailed right now) the following questions:
A) Was drain tile installed around the house? If so, does it have an exit pipe to daylight?
B) Were the basement floors and walls both sealed and waterproofed?
C) Was a plastic layer put under the concrete in the basement as a vapor barrier?
12. Another potential contributing factor could be the inadequate guttering on that side of the house, which could be soaking the ground near the longest wall in the basement rec room.
13. I keep two large-capacity dehumidifiers running constantly in the two unfinished rooms (with the doors almost always opened to the two finished rooms). During the winter, they don't suck out much water, but during the summer, I have to empty them twice a day. I also always keep on the ventilation fan (just a bathroom-type model) in the ski room.

Pictures -- I forgot to take them today, so I'll wait until Wednesday morning when I have daylight. (Although here are some older and pretty much entirely irrelevant photos of the basement: https://plus.google.com/photos/11836...26844185159745)

Thanks for any feedback, and I fully realize that a situation like this is difficult to diagnosis over the internet, but I'd like to be more knowledgeable with what are likely to be many discussions among many competing opinions from the various basement specialists and the developer and . . .

[bigdude2468]

You are on the right track with the questions you are asking. Not sure the type of flooring you have is relevant except from the standpoint of how it reacts to moisture and then being able to clean it up. The fact it turned blackish to me would indicate mold / mildew. (always call it mildew... mold technically requires remediation by an expert) I assume you have no sump pump which would require tile around the foundation. Is the soil heavy as in clay, or is it lighter sandy soil that would drain well? I used to live in the Midwest and everyone had sump pumps, gutters and downspouts to direct water away from the foundation. Almost all water in the basement problems can be traced to inadequate gutters / downspouts or grading that directs water toward a house instead of away from it. I have not heard of a vapor barrier being placed prior to pouring a floor. In doing a little searching it appears that the jury is out as to it is a good idea or not, I found yeas and nays, some said it causes more problems than it is worth.

It sounds like you do not have any direct points of water entry, just moisture weeping up as vapor through the slab, getting the rain away from the foundation is the cheapest fix you have. Your basement looks like mine did when I had two kids racing, way too much money tied up in ski equipment, good luck...

[OSECS]

Seal/tape a 12" square of plastic to your slab and monitor it for a 24 hour period. if you see moisture develop under the sealed plastic you know you do have a moisture issue.

[Jonathan S.]

Thanks for the feedback. And correct on the lack of a sump pump.

So continuing the saga, the developer responded to my questions as follows:

1. "We install a perforated, PVC perimeter drain, bedded in crushed stone and surrounded by a geotextile filter. That drain runs completely around your house and exits to daylight. That drain was inspected and approved by the Amherst Building Inspector prior to backfilling the foundation."

2. "The concrete exterior of the basement walls are treated with two coats of asphaltic sealer prior to installing the perimeter drain. This too was inspected prior to backfill. Mercier Carpet treated the concrete floor with sealer prior to installing the VCT and Marmoleum."

3. "We install a plastic vapor barrier prior to pouring the concrete slab in a finished basement."

Note the curious verb tense.

But anyway, even taking them at their word (regardless of verb tense), we had someonecome by yesterday, but he was utterly worthless: his only apparent solution to any basement problem was to install an exterior drainage system and sump pump, entailing major excavation work (and major $). He just didn't seem to be knowledgeable about anything else.

Today's guy was clearly more knowledgeable and capable. As well as more thorough, since he looked in more areas of the ski/work room, and pointed out what should have been obvious (to both me and the developer):



Maybe a little fuzzy, but probably something like 1/3 or 1/4 of the VCT tile seams have this kind of puffy white stuff, which apparently is . . . mold?!?

That would seem to mean that impermeable objects placed on top of the marmoleum tile for extended periods of time is not the problem, but instead slapping tile (of whatever type) straight on top of sealed concrete is the problem.

Or so this guy says.

He also say $1,500 to thoroughly clean the basement, then $5,000 in the fall (i.e., once we can do without the AC for a couple days) to demo the tile and existing sealant.

Then more to install DRIcore subfloor plus whatever we want to put on top of it.

The developer is stopping by tomorrow -- to be continued...

[bigdude2468]

Thanks for the feedback. And correct on the lack of a sump pump.

So continuing the saga, the developer responded to my questions as follows:

1. "We install a perforated, PVC perimeter drain, bedded in crushed stone and surrounded by a geotextile filter. That drain runs completely around your house and exits to daylight. That drain was inspected and approved by the Amherst Building Inspector prior to backfilling the foundation."

2. "The concrete exterior of the basement walls are treated with two coats of asphaltic sealer prior to installing the perimeter drain. This too was inspected prior to backfill. Mercier Carpet treated the concrete floor with sealer prior to installing the VCT and Marmoleum."

3. "We install a plastic vapor barrier prior to pouring the concrete slab in a finished basement."

Note the curious verb tense.

But anyway, even taking them at their word (regardless of verb tense), we had someonecome by yesterday, but he was utterly worthless: his only apparent solution to any basement problem was to install an exterior drainage system and sump pump, entailing major excavation work (and major $). He just didn't seem to be knowledgeable about anything else.

Today's guy was clearly more knowledgeable and capable. As well as more thorough, since he looked in more areas of the ski/work room, and pointed out what should have been obvious (to both me and the developer):



Maybe a little fuzzy, but probably something like 1/3 or 1/4 of the VCT tile seams have this kind of puffy white stuff, which apparently is . . . mold?!?

That would seem to mean that impermeable objects placed on top of the marmoleum tile for extended periods of time is not the problem, but instead slapping tile (of whatever type) straight on top of sealed concrete is the problem.

Or so this guy says.

He also say $1,500 to thoroughly clean the basement, then $5,000 in the fall (i.e., once we can do without the AC for a couple days) to demo the tile and existing sealant.

Then more to install DRIcore subfloor plus whatever we want to put on top of it.

The developer is stopping by tomorrow -- to be continued...

The white fuzz is efflorescence which comes from all concrete, nothing to be concerned about and can be washed away. If he told you he did not know what it is then he knows nothing about concrete. All concrete does it, just to what degree. Moist conditions will result in more of it and dry conditions less. Just Google efflorescence and it will put your concerns to rest. Did either one of the guys mentions anything about the lack of gutters on what you described as the long side of the house? Do you know where the drain tile around the foundation drains to, can you see it?

[Jonathan S.]

The white fuzz is efflorescence which comes from all concrete, nothing to be concerned about and can be washed away.

Oh, that's different . . .



I'm not sure to feel like an idiot for becoming all alarmed (over his alarm), or rather to feel like less of an idiot since I never missed seeing all the mold (as it apparently isn't mold...).

Did either one of the guys mentions anything about the lack of gutters on what you described as the long side of the house?

Guy #1 thought it was a big deal, and even advised putting in a gutter first before his $5,795 drainage system.
Guy #2 thought it wasn't a factor.
I also didn't do a good job describing it in my original post. The gutter-less section of the wall is rather short, and is adjacent to a portion of the basement that doesn't seem to have any moisture issues. My original mention of it is probably more of a red herring than anything else. (It is, however, an issue with regards to damage to the fiberboard siding. I repainted some eroded areas of the siding last summer. But it's not like water is pooling up there or anything like that.)

Do you know where the drain tile around the foundation drains to, can you see it?

I'll put that on the question list for tomorrow with the developer.

Okay, back to feeling like the clueless home owner that I am -- although thanks for helping me be slightly less clueless!

[Flounder]

As bigdude said that looks like efflorescence. While normal it is drawn out by moisture so that shows that moisture is getting through your slab. Dricore and a dehumidifier may work. No easy way to stop the moisture from coming through. Sealants may work or may move the problem else if a spot is missed. Moisture will still be in the concrete trying to get out somewhere.

[Jonathan S.]

So going forward, sounds like adding yet a third dehumidifier to the basement is a good preventative measure.

But what to do about the current flooring? So the marmoleum tile seems pretty easy for a contractor to remove. But does all the old sealant need to be removed, or can another layer of sealant be put on top of the old sealant?
And remove the VCT tile? Or put another layer of flooring over it? (Or would that just be like sweeping the bread crumbs under, well, under wherever we usually hide them...)

For DriCore, some googling reveals lots of fans, as well as doubters who question the wisdom of installing a wood byproduct material in a moist environment. Seems like some entirely synthetic competitors are also available...