We need to be laying a whole lot o' pipe up in here.

February 23, 2012 7:39 AM

What should we be thinking about and considering when re-plumbing an entire house? Plumbers and experienced homeowners we welcome your advice.

We are considering buying a 3-story 1920s home where all the plumbing is original galvanized steel. There are three bathrooms, a kitchen and a laundry area. I'm not sure how a product with a suggested life of 50 years has made it to 90 years but it has. The house inspector confirmed it was in good structural shape on the outside, no pitting, the pressure is decent on all floors, but there is evidence of rust staining. It is obviously corroded to some degree on the inside.

We factored the estimated cost of replacing all the galvanized into our offer (approx. $10,000 discount). We intend to use copper where ever possible and use PEX if we encounter a difficult area that would require doing too much damage to walls or ceilings to do in copper. We have plumbers in the family, who took a quick look at the house, so this is not a DIY project. We would have the work done before we move in when the house is otherwise empty.

Our insurance company will cover the house as long as we have the 'intent' to replace the galvanized pipe.

What are we missing in our thought process? Has anyone re-plumbed an entire house and lived to tell the tale? Any advice or cautions would be much appreciated.

posted by pixlboi to home & garden (11 answers total)

I own a 1923 house. I had to tear up the floors and walls to get to all the galvanized pipes in the upstairs bathroom. That led to modernizing the whole damn thing with modern stuff, which led to a TV in our bathroom, fancy stone work, etc etc etc. The redo cost of everything is what creeped out of control.

The kitchen and other bathrooms were on the first floor and the plumbing was accessible via the crawlspace and basement. So that work was easy and cheap.

My point, 10k should be enough, until your tastes in modern fixtures comes into play and your simple vintage bathroom turns into a HGTV dream. That cost, of course, shouldn't be factored into the discount.
posted by LeanGreen at 7:47 AM on February 23, 2012

Here is an interesting article on cast iron vs. PVC for waste water; for me a difference that is significant but relatively unknown is that cast iron waste pipes are typically significantly quieter than PVC, if that is a concern of yours.

This would also be a good time to consider adding little touches like a hot water return system if those are things you might want.
posted by TedW at 7:47 AM on February 23, 2012

I am seriously considering redoing much of my house with copper up to a manifold and then PEX after that for a couple reasons - partially cost, but what really appeals to me is the idea of running small bore hot water lines to the bathroom sinks and not having to run the water for more than a few seconds to get hot water.

I'm also wanting to add a bunch of shutoffs to my water system so that if anything ever needs work, you just go downstairs and turn a couple obvious and accessible valves and the hot and cold water to the upstairs bathroom, and just the upstairs bathroom, is off.

A hot water return (even just a convection based system) also sings to me, but I question the energy efficiency of such a beast.
posted by Kid Charlemagne at 7:55 AM on February 23, 2012

PEX or similar all the way. A water "distribution panel" manifold system makes plumbing work so much easier. You barely need shutoffs for taps and toilets even.
posted by bonehead at 8:01 AM on February 23, 2012

If you have the chance, put in a return line - saves a lot of "running the water to heat up" time.

I'd suggest *against* a manifold system; you have to put each manifold somewhere, so there's more drywall/plaster to cut into. Straight replacement of the galvanized is the way to go.

Something to consider is replacing only the horizontal runs; that's where the sedimentation occurs mostly. I've replaced just the horizontal pipe and gone from no-flow to full-flow.
posted by notsnot at 8:46 AM on February 23, 2012

I would recommend all PEX all the way and as little copper as possible. PEX is more durable, easier to repair, easier to install and much, much, much cheaper. It is easy enough to install I am redoing all my distribution lines in my unfinished basement to PEX. The inside the walls plumbing is already copper that appear to be in good shape. Either do a home run system or put in cutoff valves at every branch to isolate the feeder lines.

Use high quality brass ball valves, not gate valves. Gate valves corrode, break and have very high pressure losses through them. Ball valves cost more but will work always without failing.

Don't neglect the line from the meter to the house either. It is likely just as old as the rest of your plumbing and in the same shape.

Use ABS for your waste water system. It is lighter, cheaper and more durable than cast iron. It is smoother and less likely to clog over time. It will never, ever corrode. Use glued fittings for everything you can. This makes the system much tighter and quiter as well since it is all tied together. Make sure the waste water lines are adeuqately vented if they aren't already. The real key to quiet waste water lines is good venting to atmosphere outside the hosue and being tied to structure with solid connections, something more than plumbers tape every so often. Something that is nice with glued, tight ABS is using compressed air to clear clogs. Works awesome and is way cheaper and easier than a snake.

Have the sewer lateral that connects to the city sewer system checked with a camera. If you have a failing connection their get it updated. Especially if you have orangeberg or cracked vitrified clay. If you are on septic and have a connection to city sewer available get on sewer. In my town some banks are refusing to loan on houses with a sewer connection available that are still on septic. As well as being better for the enviroment and more convenient.
posted by bartonlong at 9:43 AM on February 23, 2012 [1 favorite]

We had our 50 year old house replumbed about 5 years ago with PEX. The galvanized was completely corroded and a piece actually broke off while I was trying to work on a bathroom fixture. Constant cleaning of faucet screens and shower heads was becoming tiresome.

Why we went with PEX over copper:
1) Cost. (Raw Materials and labor (see #2)
2) Down time. Plumber said it was going to take better part of a week to do in copper. Pex took 1.5 days. Also his labor for 5 days vs 2 days.

Someone mentioned access and removing the galvanized - Several of the sections of galvanized were just cut off and left in the walls, as getting them out would have created large access panels. Made sense to me and hasn't created any problems yet.

Also we had one of the two bathrooms gutted at the time (which is how we learned that our plumbing was rotten) due a remodel. You might consider other work you want to do that might be easier before/after plumbing work versus waiting til all your stuff is in there. Like texturing for example.
posted by Big_B at 9:54 AM on February 23, 2012

I have a 1930's house with galvanized pipe that is apparently still doing fine. When I bought the house, the home inspector mentioned I would eventually need to have the pipes replaced, but suggested an alternative: having them cleaned out and lined with epoxy. This method means the existing pipes stay, essentially forever, and you don't need to tear anything up. I haven't had it done, but this sales video shows the process.
posted by procrastination at 10:34 AM on February 23, 2012

If you have the space, consider plumbing your washer and dryer in the upstairs, close to the bedrooms.
posted by lstanley at 11:23 AM on February 23, 2012

Consider roughing in some other systems while you have the open access to walls and chases. I don't know: Cat5?, Coax?, high or low voltage wiring?
posted by klarck at 11:30 AM on February 23, 2012 [1 favorite]

I fear you'll discover other replacements are necessary once the walls are open. My recent question about reframing floors is there because some drywall got too wet to salvage. Cost of replacing drywall = X. Cost of fixing everything that makes us nervous once we see what's behind the drywall = 2X. Things tend to snowball. For instance, decide right now whether redoing the plumbing means it is or isn't also a good time to remodel the kitchen or bathroom. I could see this getting tempting.
posted by slidell at 10:58 PM on February 23, 2012