Any ideas for fixing a humid basement storeage area?

[Me]

Hi all,

BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB B B B B B STORAGE ROOM B B B BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB----BBBBBBBB B B B FINISHED BASEMENT B

I have a storage room that runs the length of the front of the house under the porch. It's around 36' x 3' and has block walls.

I recently finished my basement (which this room shares a wall with) and found a lot of dripping condensation on the corrugated steel ceiling in the storage room. I posted here about it a while back and was told that I needed to coat/insulate the metal on the ceiling that the concrete porch pad was poured on.

Well... I went ahead and insulated that metal - coated it with the greatstuff spray foam and set rigid foamboard insulation sheets under the coating. Seems to have worked pretty well since I no longer have any visible condensation - at times it was dripping in there like a rainforest before I coated the ceiling.

While I was at it, I also thorosealed the walls - both the three under grade and the one that borders the basement. The dashes in the wall above represent an insulated steel door going from the storage area to the basement.

Anyway, it's all done now, but the results weren't what I expected... I put a humidity guage in there and while I don't see any visible water or condensation, it's pretty much stuck around 90% humidity. In the basement area it stays at around 50%-60%, but that goes up if I leave the door to the storage area open.

Any idea what could be causing this? I need to get that number down so that I can actually use that storage area for storage! :)

Thanks!!!

[dpb]

Me wrote: ...

Yeah, you have a closed area underground in an area that outside obviously is saturated or may even have underground water flow. You've slowed down the moisture infiltration, but not completely stopped the vapor flow.

Only way you can do that is to start on the outside and figure out what the source of the water is and either divert it away from the basement walls before it approaches them and then add additional waterproofing outside as well.

Almost surely you would still need a dehumidifier in the storage area to keep the humidity down. You could try the expedient of a dehumidifier now, but it's likely not going to be sufficient by itself, but it just might if enough capacity and you once get it dried out some...but given the symptoms initially described, there's too much water on the outside--you're basement is acting essentially as a concrete boat hull.

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[Doug Miller]

In article , Me wrote: [...]

The normal solution to excess humidity is a dehumidifier; thought about giving that a try?

[Joseph Meehan]

Venting and dehumidification. The lack of ventilation is what I would tackle first.

[Me]

Thanks for the replies - what kind of venting is in order? Into the basement area or to the outside?

I did run a dehumidifier in there right after sealing it up in the hopes that it was just leftover moisture from before I sealed it... I let it run for 24 hours & it dropped the humidity down to around 60... but I think it would be prohibitively expensive to run it all of the time in there - plus there's not a drain so I'd have to empty the bucket all the time.

"Joseph Meehan" wrote in news:472a09b4$0$9579$ [e-mail]:

[dpb]

...

Yes. :)

Anywhere to move the air and circulate will help. Of course, if simply exhast it into the rest of the basement and there's nowhere for it to go there, you'll just reach a new equilibrium overall.

Your only real solution is to solve the outside water problem or evaporate/exhaust it once it's inside. That's simply the reality of once the water vapor is inside, it has to be removed in one of two ways

-- exhausting the air that carries it somewhere or evaporating it out and removing it as liquid. There are no other places for it to go, so you would be better off keeping it from coming in. You've made progress, but ...

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[Stormin Mormon]

Instead of insulating the ceiling, maybe a vapor barrier on the floor. And on the walls. Also "gutters and grading" to take water away from the house.

Then, either ventilation or dehumidifier.

[samurai]

That sounds the ground is soaked, and the need for weeping tile along the outside of the house, properly filled with drainage rock against the brick. Also on the outside, it could be coated with a 'tar' spray. This could be real expensive fix.

Do you have eavstroughs, that drain away from the house?

Check the ground around the house is not settled towards the house, and slope it away.

Also, check for cracks in the floor, maybe moisture is coming up through the floor.