Plumbers NZ is New Zealand's largest online plumbing, gas and drainage resource. Plumbing exam help, plumbing news, directory and free quotes.

Author Topic: preslab  (Read 4622 times)

0 Members and 1 Guest are viewing this topic.

Offline 15mmhexnipple

  • Jr. Member
  • **
  • Posts: 14
  • Karma: +0/-0
preslab
« on: July 05, 2010, 07:58:44 PM »
when running sewer/wastepipes under a concrete floor my company now suggestes that we run everything in 100mm pipe, from the street right up to the floor below the fixture, where we just use a 100mm slab-bush at floor level, i have also been told this is cheaper than using 6-8 100x65/50/40 junctions because you have to have them sitting up at 2 o'clock, and you also need bends between that and the pipe you are trying to run, so you save on fittings and your main line (australian standard)

when coming up to a shower in a concrete floor we just use a 100x40 level invert and between 500mm and 1m of 40mm pipe, glued with a cap for testing,

what do you do?

Linkback: https://www.plumbers.nz/ask-plumbers-trade/43/preslab/431/

Offline Thunderhead

  • Sr. Member
  • ****
  • Posts: 341
  • Karma: +37/-3
Re: preslab
« Reply #1 on: July 25, 2010, 09:17:53 PM »
Do all slab work in 100mm pvc as its cheeper and the oversized pipe, and will increase the amount of ventilation in the system minermising the risk of pipe running full bore pulling on the water seals also its a heck of alot harder to block a 100mm pipe than it is to block a 65mm pipe. and where fall is minimal the 100 can carry more fixture units at reduced grade than 80mm/65mm.

When doing a slab shower we will use a 100mm allproof tile flange with a small section of 100mm on to a 100/65 trap level inverted in the 100mm branch drain.

Offline Wills

  • Jr. Member
  • **
  • Posts: 6
  • Karma: +1/-0
Re: preslab
« Reply #2 on: August 07, 2010, 05:21:31 AM »
Here in Australia..

This is not how we do it ,think 100mm is alittle over kill! More digging for you! But well with in the standards...

"This is how I would do it". ..not sure if your gonna understand the terminology? Coooooooos having a hard time understanding yours..

Think I know what your asking for is another way? (For the shower)

Working back from shower to main sewer working with 100mm...(only)
 
100mm  riser  (straight 100mm pipe about 300mm long)( Capped for the grate)
100mm 4way riser for (Waste pipes)
100mm gully (water seal)
100mm I.O 45 degree (Case of blockage)
100mm Y junction off the sewer line... Done!

Hope this helps and what you were asking for???




Offline fdiola

  • Newbie
  • *
  • Posts: 1
  • Karma: +0/-0
Re: preslab
« Reply #3 on: August 16, 2010, 03:43:00 AM »
Here in Australia..

This is not how we do it ,think 100mm is alittle over kill! More digging for you! But well with in the standards...

"This is how I would do it". ..not sure if your gonna understand the terminology? Coooooooos having a hard time understanding yours..

Think I know what your asking for is another way? (For the shower)

Working back from shower to main sewer working with 100mm...(only)
 
100mm  riser  (straight 100mm pipe about 300mm long)( Capped for the grate)
100mm 4way riser for (Waste pipes)
100mm gully (water seal)
100mm I.O 45 degree (Case of blockage)
100mm Y junction off the sewer line... Done!

Hope this helps and what you were asking for???





Very detailed and helpful nice!


Offline GMcT

  • Jr. Member
  • **
  • Posts: 14
  • Karma: +0/-0
Re: preslab
« Reply #4 on: August 21, 2010, 05:55:16 PM »
I'd use 100mm for the lot, apart from the shower. If its a shower tray, it'll more than likely have a easy clean trap with a 40mm outlet. With a slab shower, loads of different methods.
Like I said before, for most your risers coming out the slab, I'd use 100mm. However, if you have an exposed concrete floor, this will become an issue because the standard 4x2 wall will probably NOT cover the pipe, leaving it for all to see. Even if the plumber is bang on to the mm, the concrete placer probably wouldn't get the best finish against the pipe (so you'd still see it). In this case you'd have to reduce it in the slab.

Enjoy

Offline leaky

  • Jr. Member
  • **
  • Posts: 5
  • Karma: +0/-0
Re: preslab
« Reply #5 on: May 22, 2011, 01:02:17 PM »
Thats fine,obviously depends on the shower(being tiled or fixed shower base).
i normally do 100mm everything under the slab,even shower,and cap off using 100mm cap and test.
i always come back and install a 100 by 65 level invert and then a 65 by 80mm pvc trap.
finishing with a tile flange and grate(tile shower).
or a 100 by 40mm level invert to a easyclean trap for a shower base.
cheers.



Share via digg Share via facebook Share via linkedin Share via twitter
 
Share this topic...
In a forum
(BBCode)
In a site/blog
(HTML)