Running my own ducting

I am considering switching from Virgin Media to Yayzi and I know I would need to run some new ducting for the fibre. My front yard is fully paved, so I would need to lift some slabs in order to install the ducting.

Obviously we would need to ensure that the ducting is suitable in that there are no sharp bends/kinks but I have no idea what type/brand of ducting would be suitable and at what depth it needs to be laid etc.

Can anybody point me in the right direction?. I am happy to pay for a proper site survey and for the laying of the ducting - although I will get my own team to dig up and replace the actual paving. I would rather have the cable duct laid in advance so the fibre can be simply pulled through on the day

No idea if this is the same everywhere, but the CityFibre area near and around me are all on poles no underground work (other than to get the fibre to the pole). They did this as it was cheaper but not sure if thats the same for you :slight_smile:

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I think that you can have (not sure if it’s paid) for a pre engineer to come out, like a planner

All our infrastructure is in the ground already so it would be better to run the last few metres underground too. Keeping the cables out of sight will pleas my wife too :grinning:

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The wife approval factor is Definitely key!


You’d probably need to speak to CityFibre. It will depend on if they use poles or underground and if underground, they may need specific bits and pieces, eg what direction, where it enters the house, what direction it comes from the cabinet (if underground), where the nearest cabinet / junction is, etc.

I’m also pretty sure you can’t speak directly to CityFibre. So this may be one for @Yayzi_Team

Hi there, yes you can do this, and the engineer will be more than happy for you to do that, the ducting they pull is 7mm micro ducting and is brown.

The ducting can bend but is easily crushed under heavy objects like slabs/concrete blocks.

The ducting can bend for example in a 180 arc with a span of 80cm-100cm so does have a lot of flexibility but does like to bend back on itself!

It’s a great idea overall to place your own conduit in before the engineer arrives, just let the engineer know what you’re doing.

Any questions let me know, I have worked on the city fibre contract for numerous years now & here because I’m finally installing it into my own house!

How, if they are coming off a pole that is down the road (for instance) are they going to be able to get it down your duct?
Are they going to pay for a duct up or down the road to the on prem duct?
How does that work?

How the original poster has described it he is on the underground network which is either directly buried to the green cabinet (Secondary node) to the closest point to his house that is still public property, (black box on the pavement) or uses BTs Physical Infrastructure Access that is using BTs pits that also go to the green cabinet.

Poles have cabinets or what we call Aerial Secondary Nodes at the top of the pole, which would span a fibre dropwire from the pole to the top of the customers house.

Hi there,
Ok thanks for the info, I just wondered how that would work.

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You are correct Joe, there is a green cabinet about 10 metres away outside the property next-door. There is a small black cover plate just outside my property. Everything is underground.

I am looking to understand the nature of the conduit i could lay under the slate slabs in my front yard so that the cabling to the house is completely hidden from view.

I am perfectly happy to pay for professional advice and installation.

I recall seeing some reviews of CF installs, possibly on ISP Reviews, and they happily laid the cable under block paving so you probably don’t need to supply your own ducting.

For me it was through some front lawn to the wall and then round the outside wall. I think they quite like a direct route from the path to a house wall where they then stick their brown box.

Your best bet would be to discuss it with them but not sure how you arrange this? I told them where I wanted the ONT to end up on th day, although as I said, it was quite simple as it was lawn rather than paving.

@Yayzi_Team how much do they charge for a pre install engineer? :slightly_smiling_face:

The conduit Cityfibre run is 7mm iirc, purple underground then coupled to a brown cable above ground to the Fibre Connection box.

Mines underground from a green box up the road, shared with Openreach duct.

If you install your own use something like 20mm flexible conduit.

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Flexible conduit has grooves and ridges in it, it may prove hard to pull through a fibre cable over a distance as it will probably get snagged in the grooves. I would go for something smooth if you can.

You generally leave a pull rope inside it, with both ends being available to pull the fibre in.
Our contractor puts a flexible tube holder in, which connects to a device with a compressor which then blows the fibre in

You can get smooth bore flexible conduit.

Cityfibre push through the purple conduit from the your house to the Green Box. The fibre is blown through the purple conduit.

If you run your own conduit for the internal run then a drawstring and a smooth bore conduit are needed.

Many thanks. This looks like what i need

I had similar concerns. The install team had no problems lifting my block paving and did a tidy job running from the toby box to my exterior wall.

I ran ducting from a hole I drilled in the exterior wall, through beneath my wooden floor to a central location. The install didnt go well, CF pulled my pull cord all the way out and then claimed it “snapped” (it was intact still). My suggestion would be to watch the install closely. Theyre probably not used to doing anything non-standard, but were happy for me to crack on and do it for them.

My termination in the brown external box is just a SC/APC coupler, so you can absolutely replace the internal cable run post-install