Posijoist ducting and runs, how.

[Onoff]

35 minutes ago, PeterW said:

OK

 

The Wiring Regulations require that wiring is clipped or supported at minimum x-mm intervals and other such things which @ProDave or @Onoff can probably quote in their sleep. How you achieve that is entirely up to you (or your electrician) as long as it meets or exceeds the requirements.

 

DHW and Heating circuits don't need to meet as stringent guidelines although the Domestic Services Handbook would advise good practice.

 

 

 

It's about to change some, fire "proof" method of clipping etc. This shamelessly re-copied from another forum:

 

https://electrical.theiet.org/wiring-regulations/18th-changes.cfm

[Triassic]

23 minutes ago, epsilonGreedy said:

 

I am trying to plan my self build way ahead. I have 6 months to work up a solution so I might start eating 5 Fray Bentos meat pies a week which should create enough material to fashion up a posi joist cable conduit.

 

I was told to use old plastic guttering.

[epsilonGreedy]

On 3/1/2018 at 13:01, PeterW said:

He probably needs to speak to Wavin about this.... Hep2O provides a 50 year guarantee

 

 

I thought Wavin was a forum member!

 

Anyhow plastic plumbing is beginning to sound interesting and relevant to my situation, thanks for the lead.

Edited March 5, 2018 by epsilonGreedy

[ProDave]

On 01 March 2018 at 13:11, PeterW said:

OK

 

The Wiring Regulations require that wiring is clipped or supported at minimum x-mm intervals and other such things which @ProDave or @Onoff can probably quote in their sleep. How you achieve that is entirely up to you (or your electrician) as long as it meets or exceeds the requirements.

 

DHW and Heating circuits don't need to meet as stringent guidelines although the Domestic Services Handbook would advise good practice.

 

 

Actually like a lot of other things the wiring regs are not very helpful full of phrases like "adequately supported"

[Russell griffiths]

51 minutes ago, epsilonGreedy said:

 

I thought Wavin was a forum member!

 

Anyhow plastic plumbing is beginning to sound interesting and relevant to my situation, thanks for the lead.

I think plastic is something to look into. 

Try to imagine how you get a 3m length of copper through the middle of those posi joists ?

[Nickfromwales]

1 hour ago, Russell griffiths said:

I think plastic is something to look into. 

Try to imagine how you get a 3m length of copper through the middle of those posi joists ?

You can get a length of 15mm copper in by forcing it, and then straightening it back up when it's in there. Tricky at 300 centres but 400 & 600 isn't difficult. Something you have to do if running gas . 

22mm is simply cut into 800-900mm lengths or whatever will go up and then   joined with straight, soldered connectors. 

 

Standards for clipping cables and pipes is basic common sense from the relevant trades, so unless your doing this yourself you should really be asking your chosen trade and then double checking here that they're proposal is sound. 

With posijoists this really couldn't be easier, but the main consideration almost always forgotten is penetrations through the steel UB's ( for soil pipes / mvhr and other items that cannot jump over / under with reasonable ease / practicality ) so I think that should compliment this thread too as one affects the other. 

A couple of holes for pipes & ducts plus a couple of letterboxes in the steels for cables and small bore plumbing should be factored in at the design stage. Only made easy if you get the trades on board early to knock heads, or have someone do some basic M&E design on your behalf, or use a good PM and engage them early enough for this to be facilitated. 

Quite a major one imo.  

 

 

[jamiehamy]

1 hour ago, Nickfromwales said:

 the main consideration almost always forgotten is penetrations through the steel UB's ( for soil pipes / mvhr and other items that cannot jump over / under with reasonable ease / practicality ) so I think that should compliment this thread too as one affects the other. 

A couple of holes for pipes & ducts plus a couple of letterboxes in the steels for cables and small bore plumbing should be factored in at the design stage. Only made easy if you get the trades on board early to knock heads, or have someone do some basic M&E design on your behalf, or use a good PM and engage them early enough for this to be facilitated. 

Quite a major one imo.  

 

 

Never a truer word said... Ask me how I know... ? we found a way around the issues but life could have been easier! 

[epsilonGreedy]

2 hours ago, Nickfromwales said:

With posijoists this really couldn't be easier, but the main consideration almost always forgotten is penetrations through the steel UB's ( for soil pipes / mvhr and other items that cannot jump over / under with reasonable ease / practicality )

 

 

This sounds like important advice that I need to comprehend but I fell at the first fence, what is a steel UB? UB is not described in the abbreviations thread.

[Mr Punter]

beam

[Onoff]

53 minutes ago, epsilonGreedy said:

 

This sounds like important advice that I need to comprehend but I fell at the first fence, what is a steel UB? UB is not described in the abbreviations thread.

 

An "I" section beam, in this case Universal Beam. Think of the old RSJs shape though they had taper flanges.

 

RSJ - rolled steel joist

UB - universal beam

UC  - universal column

 

All the above are "I" beams as in section they look like a capital i.

 

RSC - rolled steel channel (tapered flanges)

PFC - parallel flange channel 

RSA - rolled steel angle

CHS - circular hollow section (aka tube/pipe)

RHS & SHS - rectangular / square hollow section (aka box section)

 

etc

 

 

[Nickfromwales]

@ProDave Any chance you could copy these into the Glossary thread when you get a spare 5 mins please? 

[Onoff]

If ever anyone needs M12 galvanised taper washers give me a shout...or 1/2" Whitworth galv nuts and bolts...or inglefield clips...