I'm installing a basement bathroom in my 1925 house in Minneapolis. I've just opened my floor and found my main sewer line buried 6 inches below the slab. I'm pretty sure that is deep enough. Now I just need some help laying out the fittings. Since I have such limited space I can't really add alot of vent pipes but I'm not sure I need to since all the fixtures are so close together. My original plan was to have a vent for the toilet, vent for the shower and a separate drain for the sink and laundry. All would drain into the 3" pvc pipe from the toilet. However, when I started picking out fittings I realized I really don't have room for all those pipes. Here is my new plan. The right side of the drawing represents the wall and the left side is the floor. The scale may not be accurate but the measurements shown are accurate. Does anyone have any thoughts on this? Thanks.

I am ready to put in my sewage pump. My builder set up a vent pipe and pipe to tie into my lateral field right above where the pit is. The plumbing from the shower, sink and toilet all go into the pit from below the floor. My question is I would like to run a drain from a bar sink into the sewage pit but I cannot tie into the below ground pipes so can I run a drain to the vent pipe just above the sewage pit so that it would dump into the pit from above. It seems logical that it would work but I thought I better ask someone who knows more about this.

The existing vapor barrier technically isn't 'waterproof' but it does have a very low water vapor permeability rating. And, unless the several sheets of vapor barrier used under the entire home slab weren't taped/sealed to one another at the edges, it's not a perfect installation either. All this to say, don't lose too much sleep over what you do, do the best you can. I would feel comfortable removing a little more of the edge gravel and inserting a patch membrane up under the existing slab as far as I could to get a decent overlap between the old and new. If you can tape/seal these edges together, great! If not, when you pour your concrete patch, work the concrete up under the existing slab as far as you can to force and hold the two overlapping pieces of membrane together. And, keep that sump pump working properly.

@Amir Ali - I just wanted to post a comment in order to: 1. Let you know that I completely understand what you are going through right now. I have TWO FAILING slate floors that are part of current bathroom renovations. The master bathroom floor had not been grouted due to delays on his part. I discovered that some of the tiles were COMPLETELY LOOSE - and some sounded like they were only partially bonded to the floor. This floor is failing - and it has BARELY been walked on because the bathroom renovation basically stopped due to issues - bathroom isn’t usable so the only use has been when I’ve gone in there to take photos or measure something = maybe some tiles had been walked on four or five times before I started discovering the loose tiles. It is obvious that the tiles failed to bond to the floor - the mortar must have skinned over or something. I am NOT reinstalling the loose tiles. IMPORTANT - my former contractor does not fit the definition of what people here on Houzz love to refer to as a “hack” (at least not the actual business that I hired to do the work) - however, his employee clearly did not know what he was doing (or just didn’t care) - and that makes the owner of the business liable for this work. The business has hundreds of Google ratings (4.9/5), owner is a member of TCNA, I had several reviews from people I know (and trust), and I DID NOT JUST TAKE THE LOWEST BID - I am NOT a CHEAPSKATE. I am so tired of people AUTOMATICALLY blaming the homeowner when they have ZERO basis to do so. Making assumptions and basically telling homeowners that they are IDIOTS and CHEAP really makes me upset. Okay, I’m finished with my rant! 😂 The ”fix” is this: The ENTIRE floor is being torn apart. Not only is the tile being removed, the cbu will be taken out. New contractor assumes that he will also find that former contractor failed to add the required second layer of plywood in order to make sure that the substrate was prepared correctly in order to have a natural stone floor installed. Based upon the above issues, I investigated the slate floor that was installed in one of the other bathrooms back in April. I noticed a few grout issues - and as I went around knocking on each tile, the sound on many tiles indicates tiles that are only partially bonded. This is what the floor looks like from a standing position: And this is what it looks like when I realized that I needed to inspect it after the failure in other bathroom: I have cracks and broken spots of grout in many places. I also have some grout which is stuck on my tile because the contractor failed to seal the tile (as required) prior to grouting (I found this out later - I was in the hospital while this floor was being installed) and made promises over and over to come remedy the issue. So, this floor will also be ”fixed” in the same manner as the first one - I’m just waiting to have it ripped out until after the other bathroom is completely finished. 2. I also wanted to let you know that regardless of whether (i) you have a written contract, and (ii) that contracts specifically provides (or fails to provide) a five year (or however long) warranty period, you still have recourse against the contractor who installed your tile. Most states (probably all but I haven’t done research on this issue in every state) have enacted statutes that protect homeowners for this type of issue. In my jurisdiction, there are specific statutes that relate to home renovation projects - these statues require (among other things) that all work must be done in a good and workmanlike manner. Following industry standards, as well as manufacturer’s specifications, are part of this requirement. Also, the consumer protection act in my state also protects homeowners against contractors who perform shoddy work. I am 99% positive that your state will have some similar statutes. If you want to share your jurisdiction, I am happy to take a quick look in order to point you in the right direction. MANY jurisdictions require the homeowner to provide the contractor with notice and a right of remediation. Unless you follow the requirements of your particular statutes, you won’t be able to bring an action against your contractor to recover damages. FYI - my former contractor has chosen to ignore the notice I provided, so I then was free to hire another contractor to do the remediation work. My former contractor will owe me the money I have to spend to correct his failure to properly install my tile (which will greatly exceed what I paid him - removing tile + cbu + buying new material (including nice slate tile - because I didn’t purchase cheap slate tile for the the project initially). I am sorry that you’re going through this because it is NOT fun. I decided to consider myself “lucky” because he hadn’t yet installed this tile on my laundry floor! Hopefully, you won’t have water damage that will require even more remedial work in order to fix it.