Making cable drops airtight

[Shaun McD]

Hi all, 

Planning mode for new build and wondering about best practice for cable drops which may need to come through air tight layer. Naturally the intent is to keep these to a minimum but there will be some required for external cables, but was also wondering if there is radius issues for cat6/a which may force me to go above airtight layer?

As a solution to drops coming through the layer, what is peoples preferred approach? Would it make sense to use some sort of semi rigid material, drill the appropriate size holes for cables, and use airtight paint on both faces of semi rigid material to create a seal? The this semi rigid material can be joined to membrane via tape?

[ProDave]

Don't over think it.  Drill the smallest hole that the cable will fit through, and seal around the hole and the cable with air tightness tape.

[Shaun McD]

29 minutes ago, ProDave said:

Don't over think it.  Drill the smallest hole that the cable will fit through, and seal around the hole and the cable with air tightness tape.

 

Ha thanks, I have visions of dozens of cables coming in at certain points and nightmares on how to seal it all up ha! Im hoping that concerns about radius for data cables will be a non issue?

[Onoff]

Reassuringly expensive:

 

https://www.tlc-direct.co.uk/Products/WKONEGEL.html

[ProDave]

3 minutes ago, Shaun McD said:

 

Ha thanks, I have visions of dozens of cables coming in at certain points and nightmares on how to seal it all up ha! Im hoping that concerns about radius for data cables will be a non issue?

Why dozens?

 

That perhaps provokes a discussion of where in your build is the air tight layer?  Warm or cold loft?

 

I have a total of 8 cable penetrations through the air tight layer.

 

Not understanding the bend radius issue?

[Shaun McD]

1 minute ago, ProDave said:

Why dozens?

 

That perhaps provokes a discussion of where in your build is the air tight layer?  Warm or cold loft?

 

I have a total of 8 cable penetrations through the air tight layer.

 

Not understanding the bend radius issue?

 

Main point will be at server cabinet, centralized position for all data & AV cables. Loft is cold, with standard detail of airtight membrane on ceiling. 

I will have penetrations for external cameras, sensors, external lights, external power etc. Is my understanding incorrect that items like this would need to penetrate the airtight layer? House is TF build with an external block leaf, I assumed that an external light for example would drop down the cavity from the cold loft, with the cable routing through the airtight layer in the switch? 

I could be wrong but I think there are minimum bend radius requirements for cat 6/6a and these can be 25+mm, im assuming this be fine for 99% of locations but thought I better ask