moisture on slab? sewer leak?

[g20zoom]

I'm in san diego,ca.
1955 duplex home, 1600 sf total
cast iron piping
built on slab

During the home inspection, we discovered that the back 2 rooms on one side has a higher moisture reading than other parts of the house. 1 room has vinyl DIY tiles that are all loose, the other room as laminate flooring buckling in a 4 foot area. I think the guy said 22% moisture...it was on the highest led from that yellow moisture meter.
The nearby bathroom was bone dry. It hasn't rained for several months and san diego is pretty dry otherwise...house gets pretty warm in the day, so it's odd the slab is so moist.

We've already invested quite a bit on the inspection but are thinking of walking now this big issue came up. we are torn since we do like the place alot.

What are some tests that can be run? what's the cheapest route to determine an issue?
I would hate to pay 250-400 for a sewer line cam...i just need to know if the sewer line leaks. we watched the water meter with everything off, and it didn't move in 15-30min....hence leaning to sewer.
I've hear that cast iron don't last...and given the age, and the 6 or so trees around the house(medium to large), i'm looking at worst case scenario.

Any rough idea what it costs to repipe the sewer lines?
Any ideas how to tackle this cheap?

Thanks!

 

[havasu]

Just throwing it out there, but are you certain the moisture isn't being caused by either a poor landscaping grade or possibly a broken sprinkler line?

 

[Mr_David]

Broken drains under a slab generally don't cause excessive slab moisture.
Camera inspection may not see any cracks or minor leakage unless the problem is severe. Irrigation and even natural ground water are often the culprit.
Run away. There are a lot of homes on the market these days.
I personally would look for a home that had a plastic ABS drain system.
Old Cast Iron systems are just bad news.

These are just some images I pulled from a google image search.

 

[AJay]

Run away. There are a lot of homes on the market these days.
I personally would look for a home that had a plastic ABS drain system.
Old Cast Iron systems are just bad news.

I sure wish I had known this back in November when we were looking at homes.

Unfortunately we were somewhat set on buying in a certain area due to proximity to work places. In spite of the housing crash, what little new construction there is around here (where we wanted to buy) is still priced waay too high. Especially as we didn't sell the other house first.. and still haven't. And even if we could have afforded it, the lots were too small. So we had no choice but to buy a house with cast iron.

I guess someday I'll be forced to rent a jackhammer or whatever to break up parts of basement floor and replace the CI with PVC.

I can hardly wait!!

 

[g20zoom]

Thanks guys for the input!
Yes, the yard does slope towards the house. perhaps 18-24" starting at 15-20' out. But there is 12' deep patio cover with a concrete wall where it meets the yard. So drainage is poor...but being so dry out here, i would think that's not the issue given adjacent areas to the moist bedrooms are dry.

Well like Ajay said...it's a certain area that we like, and well....they are all 1940-1950s homes. Plus with limited land, that's the way it goes to get in. I would not prefer cast iron drains...but it's the way it is. I've heard new sewer lines could run $5-7k with cutting the slab so we'll just have to be prepared.

So today i called in a plumber and he did some diagnostics.
* slab definitely moist
* water heater hissing, pilot light on, but he didn't think that would make a hissing sound.
It believes sound is from the water coming in/out. What do you think?
* water heater hot water outlet line warm at the base, and warm going into wall - that was a 18" or so line.
he did turn on the hot water briefly, but probably not enough to heat up the whole line.
* triangle dial moving on water meter - dead giveaway, I checked on several rounds...the meter moved but took 15-30 seconds to move 90 degrees.
* he said typically the hot water lines fail in the slab due to contraction/expansion.

other stuff:
no sprinklers
no moist areas around foundation

During the home inspection...we looked at the triangle on the water meter, but the guy wasn't careful enough.
I quick 5 second glance you may not see it move.
Today it sometimes stalls...and then within a 10-30 sec period, you can see it move for sure.

For the free diagnostic tests, he's pretty sure the signs are there.
$185 (up to 2 hours) for a real slab leak detection
If it is, he would then find the hot pipe coming up from the slab in the bathroom(that shares a wall with the kitchen), cut the hot line to double check? i lost him here...
rough estimate...$1000 to repipe copper from far left of the house in garage, reroute line in attic to far right side, provided i cut the walls. leak detection fee included.

So now we have to decide to take the house or drop it...

 

[johnjh2o]

It sounds like you have a slab leak. I would repipe both hot & cold water lines. Don't waste your money on doing half the job, as all the lines are the same age and in the same condition. Don't give up on the home because of a repipe, is not that big of a deal. Get more then one price before making a decision. After you get some prices go back to the seller and negotiate the selling price.

John

 

[g20zoom]

John,
Thanks for the tips. This plumber wasn't trying to sell me on anymore. I did mention the cold line...but since that came in at the front of the house, it would get a bit more expensive to reroute that to the far left garage where the heaters are, then back to far right for the bath, kitchen. Left and right side are mirror images...so more lines.
I was definitely thinking of doing both hot lines at minimum.

The cast iron sewer is pretty old too...so where to we draw the line. House is slated to be completely redone...I know it's cheaper now but it's a gut job as almost no maintenance done for 40 years and we are cash strapped.

 

[havasu]

If the seller understands the home is in such disrepair, I would throw a low ball offer to cover anything and everything needing repair or replacement, at a substantially reduced price, and see if they bite on it. If they say no, then I would walk. Nobody wants a new home when most of the walls need to come down. You also need to keep in mind that if the existing plumbing is disturbed, and the inspectors are on top of their game, they have the ability to demand you upgrade to current code requirements, which will compound your costs and troubles.

 

[Mr_David]

I do a lot of Slab leaks in the San Diego area. Generally the hot system fails for several reasons. I do find cold ones occasionally. Normally we just reroute the hot line that is leaking. The more you do the more it cost. I also do a lot of repairs on pin holes in above ground piping.
We generally don't re-pipe the entire system. just reroute the lines going under the concrete and tie them into exiting system above the slab. But that is because a lot of the work is for HOAs and they are not responsible for the piping above the slab.

If you really like the house fix it. But look at other things like possible flooding when it really rains hard. and sometime it does rain hard.
Good Luck

 

[g20zoom]

havasu,
yep...we tried the low ball offer. they didn't bite...thinks they can do better. perhaps, time will tell. the housing market is still very strong in the core san diego area, so the strong buyers are bidding like crazy. It's hard to find a steal, but definitely good deals can be had occasionally. I guess we move on and look for another.

 

[Cranked210]

I grew up in the San Diego area and can attest to the fact that many of the homes there have the same issue. I think it's especially true with the older homes in San Diego. I'm not sure why, but I haven't thought much about it since I was a kid.

 

[Mr_David]

Look for a forclosure. Banks have alot of them these days and they want to get rid of them. I know a guy got a place in Ramona. The previous owner owed over $700K and he got it for $260K.
Guy down the street short selling his for $267K and homes in this are worth at least $350K.