Cables and Pipes...Airtightness

[MikeGrahamT21]

Hi,

 

Going to be starting the kitchen at some point soon which is in an extension I built about 10 years ago, got everything planned, but need a solution for the electrical cables and water pipes to come up through the floor (suspended wood) whilst being airtight. So i'll need two water pipes (1 hot, 1 cold) plus insulation, and then the usual plethora of electrical cables for the kitchen stuff and sockets. My initial thought was to use some semi rigid radial pipe (a bit like whats used in MVHR, but maybe 100mm diameter rather than 75mm) and leave a piece of rope through it to pull anything else through in future, should be easy enough to seal to the floor membrane on both sides.

 

The entry point is the boiler cupboard, and the exit point will be about 2-2.5m away on the opposite side of the room underneath the kitchen units.

 

Anyone got any ideas for solutions?

 

Cheers

[joe90]

With my services through my floor (gas, water pipes etc) I used a 70mm flexible duct a bit like the MVHR stuff, sealed with expanding foam then topped with silicone sealer. 

[MikeGrahamT21]

Cool, at least im on the right tracks then. How much did you fit through one pipe out of curiosity?

[joe90]

One contains wiring to treatment plant, another contains gas pipe from bottled gas, another contains incoming water main, everything else is “in house..

[scottishjohn]

would it be simpler to use builders foam around all of them to a height which you can trim off where you air tight barrier is going to be --then just tape that to the foam ?

[MikeGrahamT21]

not sure about taping to foam, doesn't seem like a reliable connection?

 

OK, will consider running a couple of pipes through, seems like a decent solution.

 

I suppose I should consider just running the pipes and cables bare as well, and taping them to the fabric, would be no different to when I did heating pipes a couple of years back and they were OK, maybe i'm over complicating things as usual! lol. I think its more the electrical wires which could do with being piped, and so I can pull new ones in if needed in future without disturbing everything.

Edited February 20, 2020 by MikeGrahamT21

[scottishjohn]

2 minutes ago, MikeGrahamT21 said:

not sure about taping to foam, doesn't seem like a reliable connection?

so tape round all the pipes and extend that down onto the  plastic sheeting --having a foam shoulder to sit on will help and you know they are air tight where they penetrate the wall

 or as @joe90 flex conduit poking through air barrier -filled with foam and then tape to conduit

[Onoff]

Wiska One Gel is reassuringly expensive...and gas tight...

 

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

[MikeGrahamT21]

wow that is expensive. I've seen airtight silicone cheaper than that! Whats the difference?

[Ferdinand]

On 20/02/2020 at 15:24, MikeGrahamT21 said:

not sure about taping to foam, doesn't seem like a reliable connection?

 

OK, will consider running a couple of pipes through, seems like a decent solution.

 

I suppose I should consider just running the pipes and cables bare as well, and taping them to the fabric, would be no different to when I did heating pipes a couple of years back and they were OK, maybe i'm over complicating things as usual! lol. I think its more the electrical wires which could do with being piped, and so I can pull new ones in if needed in future without disturbing everything.

 

Do not run the, bare .. put conduits in.  Am stuck with tiny cables in my kitchen floor because they did not conduit.

 

This is the stuff I used for runs within my conservatory for electrics.

 

About 20-25mm, flexible, inexpensive  of whatever sort.and the foam should get a key on the ribs.

 

If necessary use similar but larger as I think I did when provisioning for Virgin, with cords pre-installed.

 

Edited February 23, 2020 by Ferdinand

[Onoff]

1 hour ago, MikeGrahamT21 said:

wow that is expensive. I've seen airtight silicone cheaper than that! Whats the difference?

 

It doesn't completely set. The idea being you can stuff another cable through later or dig out the encapsulated connector blocks, WAGOs etc. They call it "re-enterable". Still messy and sticky.

 

I often fill limit switches, Amphenol/Bulgin type mains connectors, outside jbs with ordinary silicone grease. Works wonders. Totally non setting. I reckon that might work to give airtightness but nothing under pressure. 

[Mike]

See if you can buy a stop end for the duct. You can then use a ProClima or similar grommet to seal a hole though it.

 

I've seen water companies specify that you shouldn't use expanding foam or oil-based sealants as they can damage their pipes, so would suggest not doing so unless you use a product intended for the purpose.

[MikeGrahamT21]

23 hours ago, Onoff said:

 

It doesn't completely set. The idea being you can stuff another cable through later or dig out the encapsulated connector blocks, WAGOs etc. They call it "re-enterable". Still messy and sticky.

 

I often fill limit switches, Amphenol/Bulgin type mains connectors, outside jbs with ordinary silicone grease. Works wonders. Totally non setting. I reckon that might work to give airtightness but nothing under pressure. 

Interesting stuff!

[MikeGrahamT21]

On 23/02/2020 at 08:45, Ferdinand said:

 

Do not run the, bare .. put conduits in.  Am stuck with tiny cables in my kitchen floor because they did not conduit.

 

This is the stuff I used for runs within my conservatory for electrics.

 

About 20-25mm, flexible, inexpensive  of whatever sort.and the foam should get a key on the ribs.

 

If necessary use similar but larger as I think I did when provisioning for Virgin, with cords pre-installed.

 

Yeah definitely going to run the cable through conduit, was just the pipes I was thinking of taping direct to the membrane.

[Bitpipe]

On 23/02/2020 at 09:59, Onoff said:

 

It doesn't completely set. The idea being you can stuff another cable through later or dig out the encapsulated connector blocks, WAGOs etc. They call it "re-enterable". Still messy and sticky.

 

I often fill limit switches, Amphenol/Bulgin type mains connectors, outside jbs with ordinary silicone grease. Works wonders. Totally non setting. I reckon that might work to give airtightness but nothing under pressure. 

 

I used Newton Stopaq for a few service penetrations to the basement - another never setting compound.

 

Basement contractors cast in 120mm ducts for fouls and 65mm ducts for water & electric with twin Sika watertight seals on outside of the duct. I then plugged the inner of the ducts with the newton compound - was an awful job - it sticks like  $#!+ to everything, nearly impossible to clean off tools etc. You then finish with a cement compound flush to wall. Still, no leaks though!