Jump to content

Ducting sizes


Recommended Posts

Had the gas guy round yesterday who was pretty laid back with everything apart from having the gas meter under the stairs is a big no no for fire safety and gas pipe has to rise externally and enter horizontally through a wall - fair enough.

 

One thing he mentioned was having 150 gas ducting saying that anything smaller is useless for getting pipe through, so that got me wondering if that's true for gas and the other services. How have people found getting pipework through ducting? I'm pretty sure I've read posts saying make sure everything is twin walled so pipework will go along the smooth inside - but what about ducting diameters?

 

Duct runs are approx 30-35 metres.

 

Water is 32mm

Gas is 32mm

Electrics is 3 phase so been told I need to use 125mm ducting

Telephone - as supplied by BT (which looks to me 50mm semi rigid pipe that I connect together)

Extra x 2

 

Also he said I need to use perforated gas duct which is OK, but for what purpose do they sell un-perforated gas duct?

 

I need to insulate the water pipe where it comes into the house and under the B&B floor (approx 6m) but what do I use?

 

Lastly, I'm ducting everything as it goes under the drive and will leave drawstrings in all of them. So should I still use tracer wires on some/all of the pipes/ducts?

 

Cheers

 

Vijay

 

 

Link to comment
Share on other sites

14 hours ago, Vijay said:

That won't work for me as I don't even know if I'll have gas - but I want to lay ducting so I can if I choose at a later date ;)

I was in a similar position to you Vijay. I had to lay a 25 mtr of ducting I used the 63 mil perforated gas ducting with a draw cord

When was getting my quotes BG said open trench only

Gassnart quoted and said the were fine with as long as it was in a straight line 

I just had to dig a small trench at the corner of the building 

Link to comment
Share on other sites

Hi Nod,

 

I think I'll just do the gas in 150mm then as I don't really want an issue further down the line, especially as there's a bend towards the end ;)

 

The water is a gentle curve so I may just do that in 50mm as I'll be pulling that cable through. Anyone have any idea about insulating the water pipe, could I just use something like Armacell? http://www.jtmplumbing.co.uk/insulation-c555/armacell-armaflex-class-o-selfseal-pipe-insulation-c204/armacell-selfseal-armaflex-class-0-insulation-all-2-metre-lengths-pp10736?utm_source=google&utm_medium=cpc&utm_term=armacell-selfseal-armaflex-class-0-insulation-15mm-x-9mm-armaflex-15m-armaflex-15mm-x-9mm-x-2mts-co-09x015-a&utm_campaign=product%2Blisting%2Bads&gclid=Cj0KCQjwsNfOBRCWARIsAGITapZk1nWn8_uacACrESkZfnKO3xhKVzl6ljt6fd4rtNIlpdl-OfqrIdkaArU1EALw_wcB    in which case I'd get larger ducting

Link to comment
Share on other sites

10 hours ago, Vijay said:

Hi Nod,

 

I think I'll just do the gas in 150mm then as I don't really want an issue further down the line, especially as there's a bend towards the end ;)

 

The water is a gentle curve so I may just do that in 50mm as I'll be pulling that cable through. Anyone have any idea about insulating the water pipe, could I just use something like Armacell? http://www.jtmplumbing.co.uk/insulation-c555/armacell-armaflex-class-o-selfseal-pipe-insulation-c204/armacell-selfseal-armaflex-class-0-insulation-all-2-metre-lengths-pp10736?utm_source=google&utm_medium=cpc&utm_term=armacell-selfseal-armaflex-class-0-insulation-15mm-x-9mm-armaflex-15m-armaflex-15mm-x-9mm-x-2mts-co-09x015-a&utm_campaign=product%2Blisting%2Bads&gclid=Cj0KCQjwsNfOBRCWARIsAGITapZk1nWn8_uacACrESkZfnKO3xhKVzl6ljt6fd4rtNIlpdl-OfqrIdkaArU1EALw_wcB    in which case I'd get larger ducting

Hi Vijay

 

The water is the easy bit

I just put 6 mtrs of insulated blue ducting into the house and ran the pipe to the boundary leaving a 10 mtr coil for the utility company to connect to the mains I put a telescopic meter box midway between the house and the boundary and a stop end at either end of the pipe all ready for connection 

 

IMG_3191.JPG

Link to comment
Share on other sites

Definitely gas. A CAT will only detect metal so will find the electric and telephone cables. Won't be any gd for water, sewer or gas.

If you put a digger bucket through water or a sewer pipe it's no big deal just a bit messy!! If you go through an electric cable you get a lovely blue flash, if it's 33kv then it's a big blue flash and a big hole in the digger bucket. If you hit a gas pipe then it's a fairly big bill if you are lucky enough to still be here to pay it.

Link to comment
Share on other sites

47 minutes ago, Vijay said:

I assume it would be ducting, then 100mm shingle and then warning tapes/tracer wires (on top of the shingle)?

 

Ducting doesn't need shingle - compacted earth is fine with the big stones taken out

Link to comment
Share on other sites

  • 2 weeks later...

What a pain this has become! Gas people told me they want twinwall perforated ducting in 150mm - it doesn't exist!!!!!  You can either get twinwall un-perforated or single wall perforated - their answer...................................get the un-perforated and drill some holes in it O.o   I'm getting the 100mm perforated single wall pipe and I can't see why they can't get a 32mm pipe through it. 

 

The next pain is the electric ducting for 3 phase. Been told I need 125mm twinwall but can use a minimum of 100mm. They still haven't told me if that's internal or external diameter, so can anyone tell me how thick a 3 phase supply cable would be??

 

 

Link to comment
Share on other sites

150mm seems like huge overkill.

 

Are you allowed to bury it before they arrive? If so, just drill the ends they can see! I can't imagine the guys doing the installation will care anyway, as long as they can get the pipe through easily.

 

 

Link to comment
Share on other sites

Couldn't agree more, I personally think it's just so they can pull their pipework through easier at a later date.

 

Yes, that's what I'm doing now, getting all the ducts buried with drawstings as they are under the driveway and services won't actually be run/connected until next year

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...