Help - Plumbing a Shower Waste to Soil Stack

[Andrew Gordon]

HELP NEEDED - Started a project to strip out the bath from our old Bathroom as we want to replace the Bath for a 1200 Shower Enclosure.
I need advice on how to fit waste pipe under floorboard level to the soil stack outside. When access is almost impossible due to a lean to roof on the back of the property.
See photos and full thread in Projects Forum.


Read more: //www.diynot.com/diy/threads/bath-to-shower-conversion.462733/#ixzz4E5Sjftuz

 

[Hugh Jaleak]

The only option, without that great big step, is going to be to get access into the roofspace on that lean to, run the waste through there and connect to the stack at appropriate level. Personally I'd have taken the soil pipe through there too at time of construction, rather than box it in in the bathroom.

 

[Andrew Gordon]

Yes ideally that would of been the best option.
The lean to roof over the utility/ former kitchen was built with the property.
Because of the new extension, access for waste is through a cavity wall then 90 degree bend out of the extension outer cavity wall.
This means drilling through 2 cavity walls to gain access outside.
Alternatively its the utility porch ceiling down for access. Then, a strap boss into soil stack.

 

[Hugh Jaleak]

I'd cut a hole into the ceiling to gain access into that roof void, and then make a small hatch to make for any future needs. I really don't see there's any other way around it, other than the shower being up in the air. Might even be tempted to reroute the WC soil pipe through there too, making more room in the bathroom.

 

[Andrew Gordon]

Apparently routing the soil stack in the roof void was considered when they did the extension. The builder apparently said, "he couldn't do it due to the flashing ridge of the lean to is where you would bring the soil pipe out" being at the level of where the flashing is pointed into the brickwork course.
Next step is to have a look in the void and make a hatch as you have suggested.
The bathroom is quite big anyhow so space is not an issue but when you look at the interior brick wall the brickwork course is not flat it is stepped back by 15mm to accommodate the interior soil pipe. All other houses in the street are like this.
Just my luck I guess.

 

[Hugh Jaleak]

Ideally the design should have taken the soil pipe height into account, the roof on the lean to could have been a slightly steeper pitch and there wouldn't have been an issue.... Whilst the soil pipe may have to remain as is, I don't think you'll have an option for the shower waste.

 

[Andrew Gordon]

Thanks for the advice. Investigations will now commence on the lean to ceiling

 

[Hugh Jaleak]

I would assume its plasterboard. Easy to cut with a half decent saw. Depending on joist spacings and how big a person needs to get in there, you may get away with just cutting a section out between 2 joists, and tidy up with some architrave to form a hatch. As long as you can get in to fit the waste that's all that really matters.

I'd use solvent welded pipework, if done properly, it'll never leak. Just make provision for access to all sections of the waste pipe run in case of future blockages.

 

[Andrew Gordon]

There's a thing its Lathe and Plaster ceiling so will be a bit dusty.

 

[Andrew Gordon]

Took another look at my Shower waste issue the lean to roof is set further forward and the internal bathroom wall is not inline. See Photos
The inner bathroom wall is about 3' further back from the lean to.

 

[Hugh Jaleak]

Not sure what you're saying?

 

[Andrew Gordon]

If you look at the lean to roof photo.
The Lean to roof is set back 2 foot as can be seen from the side view of the lean to porch.
Also when I was stripping out the tiles we had a bit of an Ant problem coming out of the cavity.