YAHOT: How is this water getting in my basement?

[Triumph]

Actually it's not exactly a basement, I live in a 3 level end unit townhouse, and the first level is above ground on a slab. About two months ago, we had a huge amount of rain during a tropical storm and I noticed some damp spots on my carpet. I pulled up the carpet, let it air out, then noticed that the tack strip was discolored like it had seen water damage before. So I also tore up the baseboard and lower ~6 of drywall. The wood was wet, the drywall was disintegrating, and the baseboard showed signs of decay. None of this was terrible damage, but any water is not good.

Before I get too far along, here is the lay of the house, and a picture of the house from the rear. The first time I noticed the wet spots were the red circles.

So anyway, I chalked it up to having an incredible amount of rain, bought new carpet pad, replaced the sections of drywall and baseboard, and also cleaned out some of the junk that was against the outside of the house. I figured dry and rotted leaves had built up in the corner, which became basically soil, which retained water, and being next to the house the water eventually seeped in past the vapor barrier. The soil had been built up pretty high, to the bottom of the siding.

Corner in question, behind the A/C unit.

Fast forward to tonight, we had an average thundershower and I noticed water coming up again, but only under the baseboard against the shared wall. (green oval in the first image).

The water starts at about the outlet and ends at about the end of the loose tack strip.

Now what the heck is going on here? I know that I have drainage issues outside, I need to do some regrading and probably some french drains, but this water is coming from a shared wall. I should probably mention that the neighbor's slab is higher than mine, maybe 12-15 inches. But where is this water coming from? I understand that adding drainage to the other three walls will keep water from coming in near them, but the shared wall? What can I do? I have no idea what's behind the drywall besides insulation and a fire barrier.

Any ideas?

 

[Anubis]

crack in the foundation

 

[Newbian]

Your neighbor is pouring water on the shared wall to annoy you.

Check the same location in that persons wall if you can and see if they have water damage also.

 

[alkemyst]

Could be a seam between the floors of the house finally needing recaulking.

My parent's house during one of our hurricanes had water literally gushing in at the baseboard in their living room. The latex paint on the exterior kept normal rains out, but the hurricane pierced it and the builder never caulked the seam.

 

[weadjust]

Does the downspout (photo 2 behind fence) at that corner connect to a drain and if so is it draining properly. Since the source of the water damage is rain I would look closely at where the water from the gutters and downspouts is going.

 

[Newbian]

You said the neighbors slab is higher then yours so does it direct the water your way or is it sloped towards the ground away from the houses?

 

[MagnusTheBrewer]

Concrete is porous and you're down hill. Are there extensions on the down spouts? It also looks like the ground level is right at the foundation line instead of 6" below.

 

[Triumph]

Does the downspout (photo 2 behind fence) at that corner connect to a drain and if so is it draining properly. Since the source of the water damage is rain I would look closely at where the water from the gutters and downspouts is going.

It appears that it is.

You said the neighbors slab is higher then yours so does it direct the water your way or is it sloped towards the ground away from the houses?

The sloping of the ground is not the best.

Concrete is porous and you're down hill. Are there extensions on the down spouts? It also looks like the ground level is right at the foundation line instead of 6" below.

Yes there are extensions, although my downspout is having problems. But that is on the OTHER side of the house than where the problem is.

Yeah, the ground is definitely not 6" from the foundation line, and I don't see any way of getting it to that level...I'd have to angle the ground TO the house in order to do that.

 

[Modelworks]

You are going to have to do some digging to see what is going on on the outside. Really no way around that. Contact your neighbor. I guarantee that if it is wet on your side then it is also wet on their side and you both will have to work together to get it resolved.


I would remove that drywall. You are almost guaranteed to find mold and mildew behind it.

 

[highland145]

Think you should pull out more sheet rock. They come in 4' pieces so you could go that high to see how high up the moisture is. Could eliminate a problem in the neighbors place. Also, double check what weadjust said on that downspout.

Edit:^^ mold/mildew.

 

[SpatiallyAware]

I've seen this exact thing where it turned out to be a leak in someones roof TWO units over.

Long long story short they ended up paying this guy to bring in some sort of leak detection camera, who came in and traced the leak that way. I believe it cost ~$300, which is much cheaper than it would've cost to discover it by ripping out sheetrock.



As an aside, having the groundlevel up against your siding makes it very easy to bugs to get in..

 

[Triumph]

I don't even know who to call about this. I called a basement guy but he said since it's a slab he doesn't know anything about it. Seemed kinda weird. I called a drainage and landscaping place, but they're not going to have some fancy leak detection camera that finds a problem. And there's only 3 drainage and landscaping companies around here, 2 haven't called back and 1 is booked until late November.

 

[DaTT]

I would start by re-directing any water away from your home. Re-grade the earth to drain away from your house.

Does your gas line or hydro line enter your house below grade? Or even with grade?

 

[Sluggo]

You or your neighbor might have some flashing issues around the ledger board for the deck.

 

[Triumph]

I would start by re-directing any water away from your home. Re-grade the earth to drain away from your house.

Does your gas line or hydro line enter your house below grade? Or even with grade?

Both enter below grade

You or your neighbor might have some flashing issues around the ledger board for the deck.

But the leak isn't on the rear wall of the house, it's on the common wall...

 

[Squisher]

When you get behind the drywall, you'll probably find something like this:

Or it can be hydraulic pressure forcing the water up along the seam where the floor meets the wall. Caulk is not a solution. You either glue it up with urethane cement (it's a neat process where they cover the crack with caulk and inject a sealer into the crack every foot) or go outside and seal up the source.

I only had to dig down like 2 1/2 feet so it was no big deal to seal the stuff up from the outside. btw - big box stores don't usually carry foundation water proofing mat and mastic.

 

[DaTT]

Both enter below grade

BINGO! Dig it up and inspect it.

I had water enter my basement through where the gas line was cut through. I sealed it from the outside, dug down a foot and a half or so and installed a window well around the area. Now the line enters above grade. No more water.

 

[weadjust]

The gas line in your photo is entering the house above grade. It's next to the a/c unit.

 

[Triumph]

BINGO! Dig it up and inspect it.

I had water enter my basement through where the gas line was cut through. I sealed it from the outside, dug down a foot and a half or so and installed a window well around the area. Now the line enters above grade. No more water.

The gas line in your photo is entering the house above grade. It's next to the a/c unit.

Yeah, I'm not thinking properly. Weadjust is correct.

 

[Triumph]

When you get behind the drywall, you'll probably find something like this:

Or it can be hydraulic pressure forcing the water up along the seam where the floor meets the wall. Caulk is not a solution. You either glue it up with urethane cement (it's a neat process where they cover the crack with caulk and inject a sealer into the crack every foot) or go outside and seal up the source.

I only had to dig down like 2 1/2 feet so it was no big deal to seal the stuff up from the outside. btw - big box stores don't usually carry foundation water proofing mat and mastic.

When I had the drywall off the last time, I could not see that far. The wall framing prevented me from seeing that joint, and through the framing I couldn't tell what I was looking at, some sort of fire barrier I assume. I don't know how these townhouses are built - what is put between the houses? Is there a cinder block wall all the way up?

 

[mshan]

Clogged Gutters?:
If you haven't had your gutters cleaned out in years, perhaps leaves have blocked the opening to downspot in gutter and water is overflowing the gutter and traveling down wall to form wet spot you see?

http://homebuying.about.com/od/homeshopping/qt/Wetbasement.htm

 

[JulesMaximus]

Are there any water pipes in that wall?

 

[Drako]

Have you checked the flashing up on the roof, between you house and the neighbors?

 

[SphinxnihpS]

My money's on your neighbor's window due to the piece of siding under it, though there is so much going on on the back of your units, such as the deck connections, mid-gutter, downspout, rake edge flashing, satellite dish, (kitchen?) expansions with more possible flashing issues, service lines entering walls, etc. If you look at the photo the piece of siding right under your neighbor's window looks like it's coming off. I'm kind of surprised no one else caught that yet, then again ATOT is not really a go to source for construction advice.

My guess is the water is coming in from above, running down the interior of the wall and pooling on your concrete, then wicking up the drywall.

A moisture meter can help you find water inside walls without tearing them apart.

As far as who to call, call a water damage restoration company like Service Master, Paul Davis, ServPro, etc. You could get a recommendation from your insurance agent WITHOUT filing a claim. If you go that route, don't even mention what happened until you are sure you want to file, if you do.

Let us know what you find.

 

[weadjust]

Another possibility is leakage at the base of the neighbors sliding glass door. Sliding glass doors are very prone to leaking due to rain water getting in the tracks.