Hello, I am in the process of replacing the pipes in our basement. The house was built in 1948 and had old cement pipes in the foundation. The slab consisted of 10-15cm concrete resting on a compact bed of clay as well as old building debris. It leaked in more or less every joint. I am now replacing them with plastic pipes. My question now is what material is best for backfill around the pipes. I am considering using Leca balls or sand. The first one, I assume, has a capillary-breaking and insulating function, which should be good, while the sand does not have this but instead makes the pipes a bit more stable? Using the masses I have dug up doesn't feel great since there are many sharp stones that risk puncturing the pipes over time. What do the experts here in the forum say?
Another question is that I have a well upstream of the sewage system, located outside the house. I have a hard time seeing the purpose of this well. I have drainage made in the late 80s and downspouts around the house that are connected to a soakaway. Could it be an old drainage well that was used before the drainage was redone? In any case, there is water in it, so I suspect it still serves a purpose and drains water in the foundation that reaches above the sewage system level. Does anyone have an informed guess?
Ok, so trench gravel under and around the pipes. Above the pipes, maybe macadam or Leca? What would you use? and finally concrete on top. How thick layers of trench gravel should you have above and below the pipes?
I have now replaced the main pipes in the larger part of the house and placed them on gravel according to the discussion. However, I have not yet filled in the pipe trenches. The house has an additional separate drainage system for greywater (laundry room) that I originally planned to address later, but I've changed my mind and will do it now while I'm at it. This drainage was previously connected to the municipality's stormwater system. However, the two main pipes are rerouted outside the house so that everything now goes to the municipality's wastewater service.
My plan is to connect the laundry room to the new main pipes that I have just installed. It will involve a less extensive intervention in the floor if I do it this way. The idea is to locate the old main pipe to the laundry room where it exits the house and plug it. Then I will install a new floor drain and sink drain to the new main pipe instead.
My problem is that the main pipe I want to connect to is so deep, and I am reluctant to dig a meter down just to get the new pipes at the same level (alternative B in the image). What does the collective expertise say about installing according to alternative A in the image, i.e., running just below floor level and then diverting vertically towards the main pipe to be connected?
Another option that results in fewer bends is to do as in alternative C, i.e., run just below the floor and then divert at an angle towards the main pipe to be connected.
Is there any regulation or common sense that speaks against doing as in alternative A or C? Or should I bite the bullet and do it as in alternative B?
I am responding to my own question above. I chose to implement according to option B in the picture above mainly because I realized I would have to drill through the foundation of an internal wall to be able to route according to option A & C. With option B, I could dig under the foundation where the pipe would go.
Now to a new question. I am in the process of installing new pipe risers that should go up to the second floor but am confused about how to do this according to building regulations. I interpret the regulations as suggesting it should be done as in option A in the image below. The problem, however, is that the "crown" of the pipe then comes above floor level. Therefore, I advocate for option B or C. I do not understand why it would not work but cannot find any support for this in the building regulations. Are there any plumbers here on the forum who can give me some tips?
Why don't you have two 45-degree bends with a straight piece in between? It seems like there are two bends too many. Or have I missed some unwritten rule?
I had it from the beginning but had a plumber visit a week ago who saw this installation. He stated that a vertical stack should always transition to horizontal with 2 x 45.
In this case, when I have the house's base in the way, he suggested that I should have 2x45 to horizontal over the base, 2x45 to vertical down along the base, and then 2x45 to the final horizontal stack. To me, this also feels completely wrong, but if you look at the building regulations for safe water, I interpret it as if he's right.
I had it from the beginning but had a plumber visit a few weeks ago who saw this installation. He stated that a vertical pipe should always convert to horizontal with 2 x45.
In this case, when I have the house's base in the way, he suggested I should have 2x45 to horizontal over the base, 2x45 to vertical down along the base, and then 2x45 to the final horizontal pipe. To me, this also feels completely wrong, but looking at the building regulations for safe water, I interpret it as he's right.
You can absolutely have 2 x 45-degree bends with a piece in between. They don't need to be connected. It will only be better. Don't forget the cleanout above the floor.
Ok. Then it seems to lean towards 2x45 with a fitting between and a cleaning hatch at 400mm as I had before. However, the plumber I had visiting gave a very good impression. He mentioned that it was good for the slope to be slowed down as in option A or C and that it would reduce the risk of the water rushing away from the paper. I can somewhat understand that reasoning. I trust you, but if anyone else has a different opinion, please feel free to share
When I started in plumbing, a saying emerged that should be a requirement today. You must not install drains until you've learned to unclog drains! Then you'll know how not to do it.
If you make a smooth transition from vertical to horizontal with a spacer between the 45-degree bends, you give paper, heavy masses, and water the same flow through the parts. Then it's the fall of the horizontal pipe. It's called standard flow dimension.
This is where you can encounter problems. That's when you need to stabilize the pipe.
Do as you intended is the advice. The chance of blockage at the transition is practically zero. If, for any reason, the horizontal pipe needs to be flushed, it's very easy. A heavier hose can also reach down. There are only advantages and no disadvantages.
