Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 6/18/2014

What are my options for fixing plumbing issues related to cast iron pipes?

My Silver Spring, MD home was built in the 40s. The upstairs tub and bathroom sink drain very slowly and often become nearly completely clogged. The toilet seems to be ok. Plumbing on the first floor and in the basement is not a problem. At some point in the past, some pipes were replaced, but the main drain from the second floor and down is cast iron (maybe galvanized? not sure.)
To remove and replace this pipe would require significant effort and cost because it is behind walls, where there are kitchen cabinets, countertop, dishwasher etc. I'm sure the cost would be significant. I've read about other options such as running a new PVC pipe inside the cast iron pipe. Is this option, or other options, reliable? What is the cost range of replacement vs other options?

Do you have the same question? Follow this Question

Voted Best Answer

I seem to be missing the point - sounds like a good routing will solve your problem, since you said nothing about leaks.

This is a VERY common issue, and should not be - most plumbers use snakes and that is all they have - basically a spearpoint or small-diameter spring that is twisted through the pipe - look like this -

and will open up a passage through clogs, but unless very soft will generally NOT remove the entire clog - just a hole through it, and will generally do nothing about roots nor fully clean the heavy soap scum and grease buildup that lines most sewer pipes after a few years - and does nothing but scrapes about rust or roughness on the inside of the pipe. For full diameter routing, you commonly need a sewer and drain cleaning contractor, though some larger plumbing outfits have the equipment - but do not carry to normal plumbing jobs.

What you need is probably, assuming your pipes have not been getting replaced due to corrosion all the way through causing leaks (which is pretty uncommon for residential cast iron till over 100 years old), is a full-length cleaning of your pipes, all the way from the upstream-most toilet (or toilets if multiple sewer collector branches in your house) to the street, using a full-diameter router cutter blade - look like these, and scrape the pipe pretty much clean full diameter, including all but the largest roots -

(the first image, the five cutters that look like claws rather than the auger type that look like coiled springs). These scrape and cut along the side, removing the buildup and will also scrape off much of the roughness in metal pipe. Granted, the scraping can go through the pipe wall if extremely thin from corrosion, but in that case it was ready to go anyway, and that very rarely happens in residential pipe (as opposed to in industrial use with a lot of chemicals or organic wastes like packing houses). In galvanized rust through is more common, but galvanized was more rarely used for sewers, but some and 1940 is one period when they were.

Google this search phrase - images for cast iron and galvanized sewer pipe - then click on the 'images" link that comes up at the top of the page - will show you lots of pictures of metal sewer pipe. The cast iron is black or if very old and rusted reddish-orangish and uses metal banded rubber couplings (for repairs, probably used where pipe was replaced to hook to the new probably black plastic pipe) or lead-filled bell joints, whereas the galvanized pipe will be shiny silver colored (if not really badly rusted or painted) and used threaded fittings that will show a bit of the male thread at most joints where they enter the couplings or elbows or wyes. Cast iron lasts a LONG time - galvanized typically is shot in 20-40 years or so in water pipe use and commonly 15-25 years in sewer use, so HIGHLY unlikely yours is galvanized if it has been unchanged since 1940's.

If pipe replacement IS necessary, lining sewer pipe with PVC is doable but VERY hard to do IF your sewer pipe in the house is 4 inch rather than 3 inch, and increases risk of clogs with the smaller diameter. Plastic lining is VERY rarely done inside buildings and then only generally in long runs in walls or through foundations with high water table - usually that technology is used to reline the outside pipe rather than dig up a long trench to replace the pipe. Your worry about replacing the pipe in walls, behind sink and cabinets and such, can also be overcome by removing some siding and going in from the outside, if necessary, though usually only takes some 3' holes in underlying ceiling and a few in downstairs walls (if changed there too) to run the new piping, as the in-wall parts from upstairs to downstairs are only a couple of feet long - from flooring joist space up to height of upstairs floor (toilet and tub/shower) or a foot or so higher for sink, so generally does NOT require tearing out cabinets or sink - just a foot or so hole in the back of the cabinet, and much less if cut with an inside cutter.


However, lets look at your statement more closely - you say the toilet seems fine and does not back up - so sounds like your issue is that either your sink pipes need to be routed out, or if not done in a long time (5-10+ years) your traps need cleaning - which is generally the cheapest thing you can get done - probably about $300 range for a plumber or sewer and drain cleaner to clean ALL the traps in the house. That is where I would start - exposed basin and sink ones with under-cabinet access you might even do yourself if newer plastic piping - if original piping I would NOT mess with youself, and could increase cost to more like $200-300 per basin/sink if badly corroded as the original pipe will probably break when taken apart and is probably well corroded up if galvanized, so unless you want to replace all that under each sink just get it routed out rather than taken apart if old metal pipe. Be sure to talk about price up front, BEFORE he gets into tearing stuff apart, especially if original piping. For sink/basin/tub he may say he cannot rout them without taking apart and likely to break due to age, so it might be better to ask about that up front and ask about hydrojetting - cleaning using about 1000-2000 psi pressurized water jet hose with jet spray nozzle that is fed down in pipe - basically pressure washing for your pipes. I would only use that, if necessary, for individual connection drain pipes - if the main pipes needs cleaning I would use mechanical routing - does a MUCH better job. Access for that is by removing a toilet from its pipe connection to gain access indoors, and generally through outdoor cleanout riser pipe for outside pipe to street.

I would say you need to get a sewer and drain cleaning contractor with a good reputation and have your upstairs pipes routed out full diameter, and traps cleaned - or you could start with the traps and that might be all that is needed. Whether you get downstairs done too at same time is up to you - I would recommend it if not done in last 10 or less years.

Getting the routing done all the way to the street is your call too - another $150-250 typically, and probably needs done. One issue is if you clean a lot of gunk out of the house pipes routing them it goes on into the sewer pipe to the street, which if also restricted somewhere can then plug up with that junk - meaning overflowing lowest level drains in a day or so. So I always recommend that if the main house main drain pipes are being cleaned (as opposed to just one trap or individual sink or toilet or such blockage) that the full pipe be chased all the way to the street with a router. I also recommend finding a contractor who will bring his COLOR camera (B&W don't show well enough) with agreement to be at no extra charge if not used, so it is there if needed to do a run throguh the cleaned sewer to identify any broken or root-filled spots he finds during the routing. (Another benefit to routing over jetting - he can commonly feel (through his hand on cable) broken pipe and loose joints and large rocks and large roots with the router. Saves you $100-150 over the usual $250-350 range camera run charge if done at same time as the routing.

BTW - pipe replacement in wall - yeah, pricey - usually at least $500 and can run $1000 for a single upstairs kitchen or bath run to a lower level - even more if embedded in concrete slab, and that does NOT generally include patching drywall and repainting.

If I totally missed the point, reply back using the Answer This Question button right below your question.

Answered 6 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy