Damp basement...what to do?

[Zack1978]

Hi everyone,
About fourteen years ago we had a garage built and the area under the garage was excavated and it is an extra room off of the main basement. The "storage room" is connected to the basement via a normal door.

The problem with the "storage room" is that it is very very very damp. I have noticed that there are areas of "white crystals/powder" on parts of the concrete wall, which I assume is indicative of water intrusion. Also the wires for the lights and plugs in this room are run in metal pipes, and in the areas where the pipe is attached to the wall it has rusted in some spots.

The walls are painted with dry lock paint, and it is the original coat of paint from 1997. Would a second coat help? The floor is simply concrete, with no paint on it. Would dry lock paint on the floor help?
The room never gets any actual water in it, even after very heavy rains. It is just amazingly damp. The main part of the basement does not have these problems at all. I would say that the contractor who built the addition was without question a loser, who did terrible work.

So what are my options?

A dehumidifier? 1? 2? Will this be a viable option?

Does the soil around the foundation need to be excavated and new tar coating placed on the outside walls ?

Any other ideas?

Thank you for your help,
Zack

 

[KLF]

Is there a footing drain?

 

[BRUIN4]

I am guessing that the contractor that did the addition did not put a membrane or damp proofing on the outside of the foundation walls

If you can go to the expense of excavating from the outside then install a membrane against the cellar walls, install rigid XPS insulation against the membrane, install perimeter drain at footing, backfill with gravel

simplification of the process but any good foundation contractor can do it right.

 

[Zack1978]

Is there a footing drain?

Hmmm.....the footing drain would need to be in all the areas that are below grade?

Zack

 

[Johnnymiz]

how is the grading around the garage?

 

[PAToyota]

As Johnny implies, first thing I'd do is rule out surface drainage problems - downspouts emptying too close to the house, leaking gutters, grading that pushes water back towards the house.

The fact that your "regular" basement doesn't have these problems does imply that the contractor skimped on something if there aren't any surface drainage issues. Before you go crazy, dig down alongside the foundation wall somewhere to see if there is damp-proofing of some sort on the walls there. If there is none, only option is to excavate and do it properly.

Reading back through, I see that this was an addition - so not just an issue of skimping on this compared to how the rest of the house was built - that he could have done things entirely differently. Don't you remember if a foundation drain and damp-proofing was installed? What do the drawings call for?

 

[Johnnymiz]

i have a house built in 1938. there was no water proofing...people didnt live in their basements then. no drains, no insulation, no tar..nothing. no dampness UNLESS one of the kids or dogs kick the downspouts that i have to get the rain away from the house. when they do this (i cant blame the dog, but the kid can be lazy when he mows the lawn and it pisses me off when he doesnt put it back) we dont get dampness after a rain, we get an inch of water. crazy.
so...make sure you property is graded so rain runs away from the house. downspouts should get the water at minimum 3 feet from the house. ventilate the space.

 

[45Kevin]

You know, maybe good ventilation will solve this problem.

Is it heated?

Even a vent at the top and bottom of the wall or door may help.

 

[mwalls54]

Hi everyone,
About fourteen years ago we had a garage built and the area under the garage was excavated and it is an extra room off of the main basement. The "storage room" is connected to the basement via a normal door.

The problem with the "storage room" is that it is very very very damp. I have noticed that there are areas of "white crystals/powder" on parts of the concrete wall, which I assume is indicative of water intrusion. Also the wires for the lights and plugs in this room are run in metal pipes, and in the areas where the pipe is attached to the wall it has rusted in some spots.

The walls are painted with dry lock paint, and it is the original coat of paint from 1997. Would a second coat help? The floor is simply concrete, with no paint on it. Would dry lock paint on the floor help?
The room never gets any actual water in it, even after very heavy rains. It is just amazingly damp. The main part of the basement does not have these problems at all. I would say that the contractor who built the addition was without question a loser, who did terrible work.

Does the soil around the foundation need to be excavated and new tar coating placed on the outside walls ?

Any other ideas?

Thank you for your help,
Zack

The fact that your "regular" basement doesn't have these problems does imply that the contractor skimped on something if there aren't any surface drainage issues. Before you go crazy, dig down alongside the foundation wall somewhere to see if there is damp-proofing of some sort on the walls there. If there is none, only option is to excavate and do it properly.

Reading back through, I see that this was an addition - so not just an issue of skimping on this compared to how the rest of the house was built - that he could have done things entirely differently. Don't you remember if a foundation drain and damp-proofing was installed? What do the drawings call for?

I found out that sealing the walls and a footer drain is not required by my county so new houses don't even have it. So the contractor might not have done anything and it still passed inspection.

I went thru this a couple of years ago. My house was built in the 60s and the basement leaked and had water stains on the wall. I tried dryloc and hydraulic cement on the wall and it still drew moisture. I started to finish the basement so I had a water proofing company dig out around the house and reseal it and put in footer drains. once they dug out around the walls you could see that there was tar on the walls at one time but it had deteriorated due to the minerals in the soil and there was no drains around the footer.

I would find a good spot and dig down and see what you can find. Its something you want to take care of because over time the water might start to break down the concrete.

 

[Zack1978]

I found out that sealing the walls and a footer drain is not required by my county so new houses don't even have it. So the contractor might not have done anything and it still passed inspection.

I went thru this a couple of years ago. My house was built in the 60s and the basement leaked and had water stains on the wall. I tried dryloc and hydraulic cement on the wall and it still drew moisture. I started to finish the basement so I had a water proofing company dig out around the house and reseal it and put in footer drains. once they dug out around the walls you could see that there was tar on the walls at one time but it had deteriorated due to the minerals in the soil and there was no drains around the footer.

I would find a good spot and dig down and see what you can find. Its something you want to take care of because over time the water might start to break down the concrete.

Yikes! I need that concrete to be strong, since it supports the garage....

Zack

 

[WarDamnEagle]

Yikes! I need that concrete to be strong, since it supports the garage....

Zack

Water won't break down concrete. If it did there would be a lot of collapsed bridges in the world.

 

[PAToyota]

Water won't break down concrete. If it did there would be a lot of collapsed bridges in the world.

I have noticed that there are areas of "white crystals/powder" on parts of the concrete wall, which I assume is indicative of water intrusion.

Normally I'd agree with WDE. Keeping concrete damp allows it to continue to strengthen. But efflorescence indicates that you are leaching materials out of the concrete, which can be weakening it. Currently, Pennsylvania is doing a lot of repair for structurally deficient bridges for just this reason...

 

[nspctr1]

I am guessing that the contractor that did the addition did not put a membrane or damp proofing on the outside of the foundation walls

If you can go to the expense of excavating from the outside then install a membrane against the cellar walls, install rigid XPS insulation against the membrane, install perimeter drain at footing, backfill with gravel

simplification of the process but any good foundation contractor can do it right.

X2, also, not sure where your located but up north alot of contractors like to use salt in their mix to avoid freezing. The problem is is it corrodes the reinforcement after a while and if your walls are as damp as you say it could be where your "leaching" is coming from along with lime and other minerals.

GL

 

[Zack1978]

Well I purchased a new Delonghi dehumidifier at Costco two days ago. It is a self-pumping dehumidifier, so it can continually run without the need to empty the container. The machine has a room humidity % indicator, and at the moment it is reading 38%. I will keep a watch on the room.

Zack

 

[Joe_E]

Zack,
I run a dehumidifier in my basement as well. I'm in south jersey on a hill of sand and gravel. There's no ground water but i used to have a problem with rain from the gutters. I piped all the downspouts away from the house, that helped the most.

I still run a small fan constantly and a dehumidifier set at 50%.
Nothing worse than humidity in your basement as it will start to grow mold.

 

[Weedhopper]

I do exactly what Joe does. The fan really helps circulate the air.

38% sounds a little low, but I am from CT. To someone in Arizona that would be tropical.