Sealing holes in coldstores

[tex431]

Just coming to the end of a job doing a install in a large coldstore, all surface mount conduit. I've been told that where there is a penetration I.e 16mm long self tapper holding a conduit clip on the wall, or holding an isolator on the wall or anything to the 5"-king span composite panels, there should be a silicon around the hole to prevent air-loss.

I have sealed where conduit goes all the way through the wall with silicone and larger tray penetrations.

I have been on several large cold store jobs and never been asked before, anyone else had this?

 

[LeeH]

No, I've done a few installations in white walled food factories and never had too. Just used screwless clips and stainless self tappers.

 

[Marvo]

Usually you should install in such a way that no fixings bridge between the inner and outer panels. Any penetrations that go completely through for cables or pipes should be sealed with either silicone or a closed-cell foam. Never heard of having to seal short screws or pop rivets etc unless they're on the floor and could allow ingress of water during cleaning which could make the insulation sodden and reduce its effectiveness.

 

[LankyWill]

id use rivets or self tappers on this one, Marvo is spot on you have to remember thermal bridging. If a screw penetrates the outer and inner layer the efficiency rating of the insulation between is reduced by approx 60%. That sort of thing can really pi** off a smart facilities manager

 

[LeeH]

He's got severe OCD. A screw through the metal skin will have no effect on 'air loss'

How about the looses through the internal diameter of the conduit? Box lids etc.

Crazy.

 

[Darren@cseme]

Just coming to the end of a job doing a install in a large coldstore, all surface mount conduit. I've been told that where there is a penetration I.e 16mm long self tapper holding a conduit clip on the wall, or holding an isolator on the wall or anything to the 5"-king span composite panels, there should be a silicon around the hole to prevent air-loss.

I have sealed where conduit goes all the way through the wall with silicone and larger tray penetrations.

I have been on several large cold store jobs and never been asked before, anyone else had this?

I have been on coldstore builds and some clients have a spec saying where a screw or rivet penetrates the outer skin it was required to put "flashband" which is a self adhesive weatherproof strip like man made lead flashing in between saddles, clips etc and the outer skin, this is for thermal break. A little OTT in my opinion.
One thing that didn't say was required was any conduit going through into the coldstore was required to be sealed, as thermal affects will allow condensation to build.
Seen this with Fire alarm guys putting a conduit down and 3 day later fault occurred and on opening call point approx 3 litres of water poured out over the engineer.
Silicone the conduit internally at box above Roof prior to entering into coldstore stops it .

 

[MJPD29]

I've done a few of these cold stores and have never been asked to fill around the self tappers or screws, just the bigger holes