Duct Blocking Method Used by Openreach for FTTP Installations

[luhkomo]

Hi all, I'm not sure if this is the right place to ask, but it's about my current BT Fibre installation.

I have an FTTP service via BT/Openreach, where the fibre enters my home vertically through the floor of a cupboard on the ground floor. A fibre engineer recently showed me that this duct is obstructed by a "bag" filled with a substance that hardens, which is used to prevent gas, moisture, and other elements from entering the property.

Does anyone know what is it called, and is it standard practice for Openreach installations? Is it removable/replaceable?

[tonysmini018]

Yes it is the standard duct seal method, and they can be removed and replaced if needed.

[iniltous]

Its a duct seal ( inflated bag ) , it’s filled with air , obviously to introduce a new cable the bag is removed, and replaced after the new cable is installed, it is to stop gas/water entering via the duct , in most domestic situations this isnt needed as the duct is external not internal, your image suggests it’s a business setting where the duct is within the building itself …..there are other methods of sealing ducts , but that looks like the inflated bag type .

[luhkomo]

Thanks for the responses, I'm trying to educate myself a little.

The duct is located under the stairs of my house, built around 2014. A fibre engineer assessed the possibility of running another fibre through it but claimed that the seal used is difficult to remove, and they lack the equipment to reseal it. I was sceptical. He proposed an alternative of branching off the existing duct and running along the exterior wall, which I'd prefer to avoid for aesthetic reasons!

[iniltous]

Pretty unusual to have an internal duct entry on a domestic SDU ( single dwelling unit ) , not so much on a MDU , it doesn’t surprise that service delivery technicians won’t have the necessary equipment but should ( hopefully ) be able to borrow it from a colleague that deals with these situations, certainly before assuming that the duct needs to be intercepted outside and a new duct exit provided on the outside of the building, it’s not clear from the photo but is the duct approximately 2inch or 4inch , a 4inch duct ( duct 54 ) is common in business not in residential

[36ULW]

Have you already got Fibre of some kind?

That Black Cable with a Yellow Stripe looks like a COF215 Cable.

Fibre Cables usually have a Yellow Stripe to identify themselves as Fibre.

Ref to the Duct Seal Bag, just needs popping with a knife, getting it out, especially when it’s stuffed that far down the Duct is another story as on the outside is a Sticky gel tape that is an absolute b*****d to get off.

[licquorice]

@iniltous I believe internal duct entry is common practice in NI

[pippincp]

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@licquoricewrote:

@iniltousI believe internal duct entry is common practice in NI

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Correct.

[luhkomo]

> before assuming that the duct needs to be intercepted outside and a new duct exit provided on the outside of the building

This is what I was thinking. Apparently the 'civil' guys are going to come and take a look. Hopefully they'll just get what they need to get the new fibre alongside my existing one! I really don't want something going up the wall on the outside, but we'll see if I can convince them haha.

> is the duct approximately 2inch or 4inch 

Thanks for the info! Looks to be ~2 inch

> Have you already got Fibre of some kind?

Yep, I have FTTP via BT/OpenReach. I have another provider who use OpenReach's ducting through the street. I won't go into details as this is a BT forum!

> I believe internal duct entry is common practice in NI

FYI I'm in England in a Taylor Wimpey built house.

[licquorice]

Hmm, then that is very unusual