100% - that's been my (detrimental) experience too. Flexi conduit must be secured at regular intervals so that its doesn't "bunch up" on itself and then the cable that's getting pulled through gets caught - even with smooth bore conduits its the sam issue.

Lubricants may help a bit, but its far preferable to have it secure from movement.

The most important thing is to secure the conduit so the effort you put into pushing a fish tape down it is going into moving the tape along the conduit, rather than pushing it out the way. I've recently put 25mm Flexicon brand conduit underneath a floor (crawled into a basement void) to create a path from the front wall of a terrace to a cupboard in the living room where the ONT should be installed, there was 360 degrees of bends in total (4x gentle 90s) and the fish tape went through without any issue.

I wouldn't use 20mm flexible conduit as the restriction introduced by the clip-on glands loses you a lot of internal diameter even when using 25mm, taking 20mm down to 14mm or so of usable room would be frustrating if you ever wanted to pull a second connectorised fibre through.

Edited by jpm (Wed 05-Oct-22 13:48:20)

In reply to a post by tony359:

I wouldn't be able to mention a brand but something like this

That one is huge: 152mm inner diameter. But at £399 for 10 meters, it had better be good.

If you're pulling cable then it shouldn't really get snagged, even on conduit that is slightly ribbed internally. If it's getting caught then you've not taped it very well, or you're trying to get through a too sharp bend. Chuck a string through the conduit before you install it, or suck a plastic bag through with a vacuum cleaner and use that to pull the wire.

If this is for future planning I would consider 2x 25mm rather than a single 32mm, it means you aren't disturbing an existing fibre connection if you want to pull another through.

Edited by jpm (Wed 05-Oct-22 13:57:35)

That's reinforced ducting and 164mm diameter as well as £35/metre!

In reply to a post by Pheasant:

32mm is ample. The cable diameter is a smidge over 3mm in diameter. You could actually use a smaller conduit if that’s easier. The cable is pre-connectorised at the ONT end, but they will pull through the raw end to the CSP to splice it with the drop cable from the street. If you you have a draw cord in place, the engineer will be very happy.

I've got a 5-6 ish metre run through my loft between where the overhead drop wire hits the front of my bungalow, and to the top of some cable tray in my tech cupboard, (that presents itself into the floor of the loft space)

The loft is luxuriously fully boarded, and luxuriously lit with LED strip lights, so it ticks as many boxes as it can really, but when my day arrives the Openreach engineer may still refuse to go up there.

So, I was thinking, If I install 32mm conduit in the loft along that route, do I stand more of a chance to get the ONT located in my tech cupboard ?

Edit: Though I've forgotten about the CSP box, that would need to be inside the loft too, so its all probably moot ?

Edited by broadbandjockey (Wed 05-Oct-22 14:20:31)

Mine was installed through the loft without questions, and it's not boarded (let alone carpeted!) I did however install a 20mm conduit to run up the side of the house and through the eaves into the loft space. And it was FTTPoD which had been going on for nearly 18 months, which may have made a difference.

I concur with Pheasant: if you give them a conduit with a draw string, then they'll use it - anything to make their life easier *and* keep the customer happy.

In reply to a post by Zarjaz:

The issue is not only the ridges, but that the conduit itself moves overall, so if what’s being pulled through meets some resistance, then the whole shebang moves.

+1

In reply to a post by tony359:

That said, if the ridges are not too big with small dips between them, they shouldn't interfere with the pulling. It's when you have those large and rubbery ones which might become difficult.

sorry but i found myself reading that in a frankie howerd accent..........

(fetching dirty mac.....)

Gotcha all the suggestions thanks.

The link I provided was just an example of the type of conduits, I didn't really check the dimensions or the price.