Replacing old iron drains with ABS in an 18 inch crawl space, safely

[pasadena_commut]

While fishing yet another hair clog out of the tub drain the other day it crossed my mind that sooner or later all of that ancient iron drain line beneath the floor will need to be replaced. Also that it would be a horrible job. Our house has an 18" high crawl space. Something like that, I don't recall if I ever measured it. It is too low to sit up in and I have to move around on my belly as if crawling under barbed wire. The dirt is very dry and powdery and once disturbed hangs in the air forever. I have to wear swimming goggles and a good dust mask to keep it out of my eyes and lungs. The entry to this area is deep and does not extend far from the wall, and there is a wall between us and the neighbor close by, so I estimate the largest length of straight pipe that could be inserted is around 5 ft, maybe 6 if it can flex a little. For anything longer to go in a trench would need to be excavated in the dirt in the crawlspace to provide enough clearance. Main drain pipe is just under the floor at the far end and then descends gradually until it is in a trench in the dirt where it goes under the foundation. It is attached to a 4" ABS cleanout on the other side with a Fernco connector. I don't recall if that was inside or outside the foundation, but very close to it either way.

Anyway, I can see how one could unscrew, cut up, or just break up (hammer to pieces) the old metal pipe and shove it out the hole using only the existing safety gear and some hand tools. It would be miserable, but it would be doable. What I don't see is how one could safely and effectively glue ABS in that environment. The fumes would be terrible as it is a small space with very poor air circulation. Getting good joints will probably also be a problem, because the fine dirt will stick all over the ABS and would get into the glue.

How do you folks solve the ventilation and dirt problems when faced with a job like this?

 

[Geofd]

Welcome to plumbing, you will need a sawzall , and lots of diablo sawzall blades,cut in manageable sections so you can slide the old out of the hangers,if it's leaded joints cut the hubs off so it's lighter and easier to take out of the hangers it's gonna be very labor intensive so only expect to do a small amount at 1st a grinder would be best but it's gonna create to much spark, patience, slow and easy

 

[Rossando]

That's literally why we get the $$$. It's strenuous work sometimes but the actually work is easy, the other variables enable us to be creative and find solutions. Laying down tarps or thick poly film, or even cardboard is best before starting a job like that. Lots of rags to wipe fittings before and after the glue gets applied. Lots of light to get the job rolling because you will not find anything once it leaves your hand.

 

[breplum]

18" is not a place for amateurs. It is not working smarter in a space like that.

 

[pasadena_commut]

18" is not a place for amateurs.

Or claustrophobics.

Putting down a tarp (well) before assembling the ABS is a great idea, it would trap the loose dirt underneath. That would allow a ventilation blower (the kind with a long fat flexible tube) to be used to evacuate the fumes from the ABS glue out through the entrance to the crawlspace - without sucking up dirt. Although it seems like that might be an OSHA violation since the big tube would pretty much block the only exit.

 

[Mitchell-DIY-Guy]

Is any of your first floor carpeted with just carpet over plywood subfloor? If so consider lifting the carpet in part of one room, cutting and lifting a section of carpet and subfloor. This will provide access and ventilation. Easy to repair and replace.

As an FYI this “trick” is how remodelers get drywall into a basement in Michigan when there’s no other way.