Can you run plumber through a wall?

[sach000]

Hi,

I am planning to add an ensuite and a powder room to our existing home, and I intend to manage the project myself instead of hiring a builder. To make room for these additions, we’re reducing the living/dining area. We’re working within a tight budget, so we’re aiming to avoid cutting into the concrete slab.

One of the Solution provided by plumber is to 

1. Instead of building a regular wall to enclose the area, build a Cavity wall, allowing plumbing and sewerage lines to exit the house at the nearest opening, avoiding concrete cuts and achieving the necessary 1:60 fall.

2. For shower minor cutting at the edge will be required.

3. Digging a trench to the ORG (overflow relief gully) to connect the drainage to existing sewer line and adjusting the ORG accordingly.

4. Using in-wall toilets to maintain the fall to the nearest exit point, with all toilets positioned on the plumbing wall.

============================================

Questions

1. Does running sewerage lines through the wall meet Australian standards and codes?

2. Are there any foreseeable issues with running plumbing through a wall, such as potential damage to timber framing over time due to moisture or anything?

3. Should we consider insulation around the plumbing to protect against potential leaks or any other issues?

4. What methods can we use to protect the plumbing from accidental damage, like someone driving a nail into the wall and damaging plumbing?

5. How should framing be handled? With standard 90 mm studs, would we need two frames and 110+ mm cavity between 2 frames ? or 2 studs can be joined together to create wider. depth.

Thanks in advance for all the help

 

2. Use 

[JacobZ]

Hi @sach000,

Thank you for your questions about your upcoming ensuite renovation. It looks like an exciting project that I'm excited to see come to life.
 

Allow me to answer your questions individually.

1. Assuming your plumber is licenced and aware of the relevant Australian Standards, their recommendation should be followed. I imagine it is fine, but if you have concerns it might be worth getting another opinion from another suitably licenced plumber.
    
2. Running plumbing through walls can sometimes lead to moisture issues, especially if pipes leak or they aren’t adequately insulated against condensation. Over time, moisture buildup can damage timber framing or wall materials, but these issues can usually be prevented with proper installation. I'd suggest speaking with your plumber about this concern and see what can be done.
    
3. Insulating the pipes can help reduce the risk of condensation build-up and damage from vibrations. Once again, your plumber's recommendation is likely the best thing to go off here.
    
4. Oftentimes, the best thing you can do is keep photos with measurements for reference, so you are aware of where in the wall your utilities run. Having your pipes run through a cavity wall, the risk of a nail hitting your plumbing is very low. As the pipes will run behind the timber frame, it's extremely unlikely that a nail could travel that far with enough force to penetrate your pipes. 
    
5. To ensure the strength of your walls, it would be best to have two separate walls with a cavity between them. If you were to use larger timbers or laminate studs together, you would end up having to drill a 110-120mm hole in every single stud, which would weaken them considerably. 
   
   If you want to reduce the thickness of your wall, you can likely use 70mm timber studs or steel studs to reduce the thickness.

Allow me to tag @Dave-1, @Nailbag and @Jewelleryrescue to see if they have any thoughts.

Let me know if you have any further questions.
 

Jacob

[Dave-1]

Good Evening @sach000 

Your project sounds interesting. The steps that @JacobZ has laid out in response to your questions really are the same things I would be saying as well.

I cant really add anything to his suggestions. Other than maybe get a second opinion from another plumber just to alley your concerns.

Dave

[Nailbag]

Hi @sach000 

Straight up thoughts would be to hire a draftsperson to design the build. They are best placed to ensure everything is built correctly and within regulations for your region. Depending on total cost for the renovation, you maybe required to apply for an owner-builder permit. Again the draftsperson can advise. You can then project-manage the build yourself.

As an FYI, making cuts/trenches in the slab is not that big an issue. I have done this myself and have hired a concrete cutter professional for a few hundred dollars to minimise the plumbing route and disruption of other walls. Making a bathroom functional that maximising limited space in my mind is paramount over shortcuts.

Nailbag