... drain in crawlspace dripping anyway. I noticed the drip from 4" cast iron pipe (70 years old) while on annual termite check. Watching down-stream cleanout when upper-end toilet flushed showed water flowing - though I can't rule out a partial blockage upstream.

The primary problem certainly something I never noticed before. When I had HVAC installed in 1991 they cut one of the straps holding the pipe because it was in the way of a duct. Using a level on the pipe sections, I found this, starting from upper end: 1) segment between toilet and shower drain has good slope; 2) ~5 ft segment past shower drain has very good slope; 3) the bell and spigot joint with next segment is dripping; 4) the segment past the drip is about 2 feet long, had its support strap cut, and has only very slight slope; and 5) the next segment has very good slope.

I have installed a new strap to support that segment but did not attempt any adjustment.

Questions: A) Is this drip (wet spot in soil about 18 inch diameter) a problem that needs to be fixed?
Is there a DIY fix and, if so, what should I do?


Thanks.



Edited 2 times.

You can mix up hydraulic cement and smear it on the leaking area until a permanent fix( cut out and replace) is done

If it is leaking at the joint at a hub tapping in the lead may fix it.

I would try recalking the lead and monitor if the leak has stopped.

bsipps,

If hydraulic cement seals the leak, is that good enough to be a permeant repair? (the new strap should keep it from sagging further).

If not, is the permeant repair something I can do? Something like cutting out the old pipe, sealing the downstream end (in the bell) with hydraulic cement (or something) and connecting the other end with a flexible coupling?

Thanks.

MT,

I don't know what you mean by "tapping into the hub." Can you explain?

steve,

What kind of caulking should I use? bspiss recommended hydraulic cement. If the leak stops, can I consider that a permanent fix? If not, how would a permanent fix be done? Thanks.

The original oakum and lead were "calked", not "caulked". Calking is a term used for driving the oakum and lead tight into the joint. A calking iron (tool like a blunt chisel) is hammered to compress the oakum and lead. Calking the joint is what Mr T was referring to.

start saving to REPLACE the 70 year old CI


i would not do anything re: your small 'drip'

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Steve,

Great info! I appreciate learning something new. I am tempted to see if I could "tap" the lead a bit to seal the lead - but I suspect I am better off leaving bad enough alone.

Thank you for helping me understand how these were made.



Edited 1 times.

Bernabeu,

Doing nothing sounds good to me - and I am usually good at it.

How do I know when it is time to replace the CI pipe?

Thanks.

when it is visibly cracked or cracking

when it is 50+ years old AND leaking inside the occupied space

when it is leaking badly outside the 'occupied space'


when, upon 'tapping' inspection, it 'sounds' wrong or thin AND some of the above apply


when it is very old AND you can afford


OR


any time you are remodelling and the walls are open

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

I heard that you can tap the old lead around the joint tighter, and add new lead wool on top and tap that tight against it. May be that is worth a try? I would feel the bottom of the cast iron pipe and see if it's paper thin.

sum,

the lead is NOT the seal

the oakum is the seal

the lead merely holds the oakum in place

the lead is calked after cooling because it CONTRACTS and must be (re)'packed' tightly into the groove in the bell and against the oakum



the oakum, in and of itself, was calked into place BEFORE the lead was poured - the packing of the oakum is a simple, easy, non time consuming procedure - almost cursory in nature

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

I understand that, I was just saying that instead of pouring molten lead over the oakum, some told me lead wool can be used and I have heard that new lead wool can be tapped tight into the joint to compress the old lead and oakum further.

yes, possible

BUT

at the risk of cracking the OLD fragile 'corroded' hub

THEN

a 'major' repair is PROMPTLY in order



in the OP's case: a slight drip IN THE CRAWL SPACE can be ignored until the, hopefully planned for, repipe

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Good advice burn just check up once a year, the pipe in The Joint May Outlast the occupant

Good to know - thanks.

Personally I feel just letting it drip and ignoring it is not the best advise

Around here the crawl spaces are concrete and the water will pool and create a stench or insect/ rodent problem

Not to mention the plumber having to work in such an unpleasant area to begin with, wading in a pond of sewage that could have been prevented… I’d be a little ticked off, letting it drip until a re pipe is not the option I would go with

Smear hydraulic cement over the suspect area and start saving money for the repipe

I'm just a homeowner like you, but I second the idea of not letting it drip...I would consider using either the Flex Seal spray or possibly the paste. Slather it on the joint and it should stop the drip for a while, but the pipe is going to need to be replaced with PVC.

I think another trip to the crawlspace is good to make an assessment.

To look at the leak again close up with a flashlight to determine if the leak is coming from the seal between the hub and the pipe (in which case trying a tap all the way around can be done) or if there is a crack in the piping (which requires a more drastic approach). This should not be too difficult to determine as metal pipes with leak usually have this stain that can be traced.

If this showed up in your termite check obviously this can be a source for attracting subterranean termites and letting it drip is a bad idea.

If it's the seal then try tapping all the way around the compress the seal. You can even try to squeeze in a ring of silicone over the existing seal to give it some additional insurance. If it's a crack then there is very little that can be done because the crack with lengthen and widen as corrosion develops. The only thing that may buy some time may be a few wraps of fiberglass cloth over the crack and several applications of brush on liquid no slump epoxy designed for vertical applications. The ones they use for fiberglass boat bottom repairs would be what I would use, expensive stuff though (these are not the same as "Bondo",