Basement humidity problem revisited

[Vettedrmr]

Greetings, folks! Hope y'all had a happy Thanksgiving and are working towards a Merry Christmas!

About a year ago y'all helped me get the humidity under control in my under-house basement, and I wanted to give you a one year update. The old thread is here:

http://www.garagejournal.com/forum/showthread.php?t=273317

This past spring was crazy, getting almost a year's worth of rain in 3 months. May was the worst, at 13 inches of rain. Under these "worst case" conditions, I found that a small underground stream forms in my basement from runoff. It literally comes from out of the middle of the foundation dirt (remember my house is built onto the side of a hill), runs down the inside of the vapor barrier, and onto the small concrete floor. While this is a real-life example, it’s so extreme as I’ll just deal with it the few times it happens, sucking up the water with a shop vac.

Once the deluge stopped, things started getting under control. I’ve sealed off the vents, and am running a Frigidaire 70 pint dehumidifier. I don’t have a sewage drain in the basement, so I’m draining the condensate into a 5 gallon bucket that I empty 1-2 times a day. It’s a bit of a pain, but it also allows me to measure its performance and just basically keep an eye on things. I’m trying to keep the relative humidity down to around 60%, which is dry enough to keep fungus and mold from developing. During the humid months of the year the dehumidifier runs essentially continuously, and pulls about 8 gallons of water out of the air daily, and manages to keep the relative humidity down into the high 60-low 70s (higher than I want but low enough to keep mold/fungus growth slowed way down). When the dewpoint comes down it drops down to 1-2 gallons a day as it regulates to 60% RH.

One other item to note: Last August we had to go out of town for about a week , so I had to turn off the dehumidifier, since I couldn’t empty the bucket. As is typical, we didn’t get any rain during that period, but the dewpoint was up into the 70s. When I got home and turned everything on, it was obvious the RH was WAY up, and my humidity monitor (a separate device) said the RH was 87%, and had peaked at around 90!

HTH, and have a good one,
Mike

 

[gregtwojeeps]

I assume there is no sump pump anywhere ?

 

[Vettedrmr]

No sump pump. The yard continues to slope away from the lowest edge of the house, so I will probably try to figure out some way to plumb a permanent drain into one of the gutter downspouts, that's just not on the list yet.

Have a good one,
Mike

 

[gregtwojeeps]

I see. Well, you know where to come when you get ready to install a sump pump. Just get some pics of your yard where you are thinking of a sump drain placement and of your floor space where you want the pump ...so it will help the guys on GJ ...help you. Good luck !

 

[DenisG]

Here an install with a dehumidifier and automatic condensate pump:

I would have mounted the dehumidifier and condensate pump high on a shelf near the basement ceiling. The condensate pump wouldn't have to work so hard because the pump would have less pressure head. There's no need for the dehumidifier and pump to be on the basement floor.

 

[Vettedrmr]

I would have mounted the dehumidifier and condensate pump high on a shelf near the basement ceiling.

Actually, that's kinda what I did, although I don't have any pump. I just secured the dehumidifier to an unused workbench and have it drain into the bucket.

Have a good one,
Mike

 

[Showkey]

I shoot for 50% humidity in my basement shop and separate shop garage. The shop garage is insulated heated but no AC. I drain the dehumidifiers into floor drains. I never turn them off, I leave the set control at to cycle the units as needed.

In the basement I painted all the walls with DRYLOC type paint. ( two coats) This helps with water vapor moving through the concrete. Concrete is porous to water vapor, I did not DRYLOC the floor as they do not recommend this type of paint for for traffic. I used a acrylic floor and deck paint on the floor to seal it. Painting/sealing the walls made a huge difference in the run time on the dehumidifiers.

Vettedrmr is the basement have AC available from the duct work that supplies the upper floors. When I run my whole AC the basement is much easier to control. In my climate AC does not need to run all day or every day in summer.

 

[Vettedrmr]

Showkey,

The HVAC ductwork is accessible in the basement, but no vents are plumbed into the basement area. I'm not using this area for anything but storage, and 60% RH is dry enough to keep mold/fungus from growing and steel from rusting, which is my goal. The concrete walls are just support for the home (i.e. they have dirt on both sides.

If I ever decide to actually use the basement for work a lot of work will have to be done to make it actually useable.

Have a good one,
Mike

 

[Showkey]

Letting some of that conditioned air into the basement would go a long way to controling the humidity.

 

[MagKarl]

Have you considered taking care of the drainage problem to prevent future runoff from entering? That would be my first priority.

 

[MikeF2316]

Actually, that's kinda what I did, although I don't have any pump. I just secured the dehumidifier to an unused workbench and have it drain into the bucket.

Have a good one,
Mike

There are dehumidifiers that have built in pumps too.

 

[James-W]

Have you considered taking care of the drainage problem to prevent future runoff from entering? That would be my first priority.

That would be my thinking as well. There is an old saying, "An ounce of prevention is worth a pound of cure". I think that applies nicely here. I have no idea what it would cost to have the drainage problem fixed, it would probably be quite expensive, but I also think that long-term it would be worth it.

 

[G McKay]

A cheap quick fix. Set the dehumidifier up off of the floor so you can drain it into another bucket. Then rig up some type of small pump that kicks on and runs the water up and out through a PVC pipe to the outside. You could even get a small sump pump and set it down into a pickle bucket and have the same thing.

Mine sits next to a sump pump so I just tied a hose into the bucket and it drains into the sump pump. But you could have the same setup and run yours outside, too if you wanted. Good luck.

 

[Stuart in MN]

I have one of these Little Giant condensate pumps for my furnace, since I don't have a floor drain: http://www.zoro.com/little-giant-pump-condensate-115v-vcma-20uls/i/G3199585/ It should work just as well for draining water from a dehumidifier. You run the discharge hose up and over to a sink or other suitable drain point.

 

[BonzoHansen]

I have some older little giant pumps. The older design dehumidifiers had bigger drain buckets. I put the pump in that bucket and pump to the washing machine drain. That allows the bucket fill stop to work if the pump fails. The design in the youtube video makes a mess if that pump fails and you dont see it you have a mess.

 

[rodm1]

You could use a furnace/AC pump and send it up stairs to a sink drain.

 

[G McKay]

There you go! Great ideas. A lot better than mine was!!

 

[gregtwojeeps]

This past spring was crazy, getting almost a year's worth of rain in 3 months. May was the worst, at 13 inches of rain. Under these "worst case" conditions, I found that a small underground stream forms in my basement from runoff. It literally comes from out of the middle of the foundation dirt (remember my house is built onto the side of a hill), runs down the inside of the vapor barrier, and onto the small concrete floor. While this is a real-life example, it’s so extreme as I’ll just deal with it the few times it happens, sucking up the water with a shop vac.



I see now. A condensate pump on his humidifier is going to solve the problem he stated above ? Anyone that has ever lived in a home with a basement below grade knows when water is penetrating either through the walls, under the footings or even up through the floor as a high water table will do.... knows there is no inexpensive solution....

Excavating, drainage, sealing, regrading, any or all has to be done to cure the water penetration. And if one is not home when this water penetration occurs or is for some reason physically incapable of running a bucket brigade... a sump pump will be a very nice item to have in place. ...

So in knowing this ...and in knowing the prominent changes we are having with our climate such as states having droughts where they are rare, floods where they are rare... it is very likely the OP will continue to have heavy rains....

A sump pump would lessen his stress of having to deal with the heavy rains coming out in the middle of his basement floor and afford him a place to put his humidifier drain. Then, if he chooses to.... he could work on getting his exterior drainage issue solved of which, will be a LOT more expensive to do and certainly more labor intensive than installing a sump pump. JMO

 

[Vettedrmr]

Ok, let's see about the comments:

1. To the point of "solving the problem". I'm open to any suggestions on how to keep 7-8 ft. of water table from encroaching (that's how high the upper side yard is from the basement. Guttering already sheds the water to both sides of the property from the front and sides of the house (the high side). If you're referring to French drains, two different contractors have already told me they wouldn't solve the problem, the water just comes under the drain. As I said, I'm open to ideas.

2. About draining the condensate. I've thought about installing a drain grate on the side of the slab that would capture any free runoff of the underground spring (which is a rare event), but would also provide a convenient drain point for the dehumidifier. I'd run probably 1.5" PVC and punch it into the closest gutter drain. I'm not sure about the diameter, I could use some help there. The quantity of water at any given time is small, and going downhill is not a problem.

Gregtwojeeps (what a username! ): You've grasped the problem of "solving the problem".

 

[Showkey]

http://inspectapedia.com/Wet_Basements/Basement_Waterproofing_Sealer.php


http://mildewbusters.com/basement-waterproofing/


Back to two coats of a DRYLOC or WATERTITE type paint. It can hold back 34 psi of hydrostatic pressure. In a DIY the whole project can be done for $200-300. After this the dehumidifier might run half as much.

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[sands35]

A picture of the basement floor area would be good. You seam to indicate that it is a dirt floor or is it a poured concrete floor?

It literally comes from out of the middle of the foundation dirt (remember my house is built onto the side of a hill), runs down the inside of the vapor barrier, and onto the small concrete floor.

???

Best case is to prevent the moisture from coming in at all. So french drains, possibly a sump (or not if your hill has any decent grade), rain gutters, exterior water proofing, etc.

2nd best is to stop the moisture at the wall, so interior water proofing and drains along the bottom of the foundation wall.

3rd choice is to remove the moisture from the air.

Sorry, but no really good options here.

Do you know where the water table is? It is not unheard of for a house to be build on top of a spring.....

 

[Vettedrmr]

Here's a photo of the basement, the ceiling is 7' tall. As you can see, there's no wall to try to seal. The water comes out essentially out of the center of this photo, runs under the plastic and onto the floor.

Even when it's not so wet as to actually be running water the dirt gets quite saturated during the wet season. Not enough to drain water out of the soil, but enough to saturate the atmosphere if not for the dehumidifier.

Have a good one,
Mike

 

[gregtwojeeps]

Appears to be either a high water table or spring....

Just a note, the cinder block pier area which looks to be about 45 -52 inches tall, is classified in my neck of the woods as a crawlspace... Now where the furniture bits are laying may be 7 ft. tall basement ? You can still go in where the water is coming up in the CS and dig a small trench with rock in it to a sump pump barrel installed in the 7 ft. tall space dirt floor. JMO

 

[Vettedrmr]

Hmm. Well, what I *usually* get is just damp dirt, and it's usually fairly uniform. The idea of a stone drain path is interesting, although I'm not sure how effective it would really be.

I think I can go towards this in two phases: first, get a drain from the center of the dirt installed that I can run the dehumidifier drain into. Second, put in that stone drain path you suggest.

Thanks, and have a good one,
Mike