Long waste run

[bathstyle]

An En suite shower Room (no WC) that I inherited had the waste pipe for the shower and Basin notched into the joists, going totally against Regs and weakening them beyond belief.

I propose to take this pipe out and strengthen these joists with steel and look for a new route for my waste pipe.

My suggested route will take the 2" waste pipe 3 metres running parallel between two timber joists, it will then be dropped below the ceiling and run a further 4m metres before it reaches the soil stack. At the head of the waste run I plan to install an AAAV.

I have checked Document Part H and it does go against Regs as far as I can tell, off the top of my head they suggest just a 4m run is allowed.

I'm still keen to do the work regardless of the Regs, does anyone see any problems with my suggestions??

The 2" waste pipe will be used by a Basin and a Wet room Trap.

 

[bathstyle]

Anyone know of any proper Plumbing Forums where I might be able to post this topic on??

 

[doitall]

Patience Bathstyle, you could always try screwflux.

Provided the AAAV is around the appliance end, and you can get the fall I would go for it.

Maybe an idea to make some provisions for access, if it's possible.

 

[bathstyle]

Just my way of bumping the thread

Cheers for the thumbs up, I want to get this right , I guess the pipe will only be carrying fairly small amounts of water provided I don't go too mad with the Shower pump etc.

I must post the pics of the existing waste run, it is shocking

Just to add, this thread ties in with the RSJ drilling question, as the RSJ is my first obstacle before the 'in between' joist run

 

[kevplumb]

Patience Bathstyle, you could always try screwflux. icon_idea.gif

or TT

 

[bathstyle]

Too cryptic for me Boy

 

[doitall]

You can, subject to certain permissions drill through the center of an RSJ.

Don't do it off your own back though.

If you're looking at power shower, then you should be looking at 80mm and maybe 110mm.

 

[bathstyle]

This is what I was trying to work out on my RSJ thread, I'm holding out for something on that one.

The Shower most definitly will be a power shower, nothing amazing , just a digital shower, like a grohtherm wireless as I have a couple of those spare.

You suggest 80 and 110mm pipe work, if this is the case then the whole idea will be scrapped right now and I make the room into a walk in wardrobe. It simply will not be feasible to run that size pipe.

I would have no problem doing the job as per Part H with a 4m run, why is having the additional 3 or 4metres that much difference?

 

[doitall]

Doc H will give you the flow rate for 50mm pipe, then it's a question of what the shower chucks out, some of the ones we fitted are 60-70 Ltrs/min and no way would a 50mm pipe take that.

A job in London they cut, a 110mm soil pipe through a 6" RSJ

 

[bathstyle]

Had a quick online flick through Part H and also the Grohe website to check the flow rates - no luck on both counts, i'll have a proper look tomorrow

 

[gday2uk]

Shoot me down if I'm wrong but what you plan on doing (cutting through RSJ and running waste some 7mtr) sounds worse (and may still contravene building regs) than what you have got. Can't you just strengthen the notched joists somehow?

 

[gday2uk]

BTW it's an Air Admittance Valve (AAV) not an Advanced Amphibious Assault Vehicle (AAAV) or whatever.....

 

[bathstyle]

Let me explain the current set up.

The 1"1/2 waste pipe exits the room, runs 3 metres between two joists then runs approx. 5 metres across joists, notching about 8 joists, some in excess of 50mm, if you know someway of getting a 50mm pipe the same route I would be keen to hear it.

My proposition sounds sensible, I'm just after some advice really on whether it is feasible to firstly- drill out the RSJ and secondly whether it will work.

I suggest that provided the shower valve produces under the recommended flow rate for 50mm pipe, and the waste gully is suitable for the flow rate there should be no problems.

Just for information, I plan to bolt steel plates either side of each joist where nothing has taken place on existing set up.

Thanks for the replies so far, I'm really keen to hear anyones views on this, negative or other.

 

[Nige F]

Sani flow wastewater type with electrical interlock to shower pump. so if sani stops pumping, shower stops Only place I`d suggest one -grey water must be ok.

 

[bathstyle]

Thanks for the reply.

Yes, I was looking at one yesterday, Impey make them as part of their packages, works slightly differently as the flow is checked on the supply pipes to the shower valve.

Any reason why you wouldn't suggest the long run of 50mm pipe??