Leak via a roof aerial mounting

[BarumMike]

Advice please. I fitted a Poynting shark fin 4G aerial on to the roof of a 2021 Roller Team motorhome above a cupboard. Unfortunately there is now a leak into the cupboard. The aerial came with a sponge rubber gasket about 2-3mm thick, attached to the base. This had an adhesive on the underside which attachs to the (carefully cleaned) roof when the central spigot nut is tightened, pulling the aerial down onto the roof. The gasket looks to be seated correctly and the aerial remains firmly attached as judged by a sideways push and pull by myself. The leak ocurred when we took the MH out of covered storage and drove through rain to a campsite. Today after overnight rain I discovered that the aerial is sitting in a small pool of water on the roof. The aerial is at the midpoint and 10 cm in from the RH edge of the roof. The MH was parked with a slight slope to that side so that the rainwater pools against the raised moulding along the edge of roof and sidewall.
Questions. 1. Should I worry about the effect of a presumeably short lived water leak through the hole for the aerial cable on the integrity of the roof? Do I need to take some special action to dry it out?
2. Is it reasonable to simply put a fillet of Sikkaflex covering the gasket edge and bridging from roof to the base of the aerial housing, or are such botches doomed to failure? The alternatives seems to be dismounting the aerial, removing the gasket, sourcing another gasket (not sure if this is available) and refitting the aerial at the same or a different location.
3. If I go for the nuclear option of repositioning, how difficult is it to seal the first 22mm hole in the roof?

And I was pleased with my DIY effort in mounting the aerial.

 

[ivorantony]

I would loosen the nut and squeeze a fillet of sikaflex around the base then retighten the holding nut,
Job done

 

[Mike800966]

1 Yes, very much to be avoided
2 Sikaflex will be fighting the movement of the gasket
Why not refix, bedding the aerial base in sikaflex instead of gasket, and stil put a bead around the outside of the base?
Been there got the tee shirt!
Best wishes
Mike

 

[BarumMike]

Thanks Mike and Ivor. Any thoughts on drying out any damp penetration? I have a dehumidifier running in the MH. Do I need to be more active than that - not sure how?!

And tips on closing off a hole on the roof of a MH, if it comes to that? One 22mm hole and x6 5mm holes for M4 bolts into aerial ina gris pattern.

Mike

 

[Lenny HB]

When I mounted mine I took the foam pad off and just used Stika.
I would remount it using Stika.

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[Mike800966]

When I mounted mine I took the foam pad off and just used Stika.
I would remount it using Stika.

That's what I suggested. I wanted to mount a single dab vertical so I used an ally plate nicely painted and sikaflexed it into position. Why are you not using the holes again for the aerial?
Mike

 

[gus-lopez]

When I mounted mine I took the foam pad off and just used Stika.
I would remount it using Stika.

with the required 3mm gap underneath.I use 3mm tile spacers

 

[BarumMike]

Thanks again.
Gus-Lopez - can you tell me more about "the required 3mm gap"?
Mike - if I use the original position I still have the problem that after rain the aerial will be sitting in a 3mm deep pool of water half the time, (depending on whether the MH is parked sloping down to R or not). The back section of the roof seems to be slightly higher, has no elevated seam rearwards and has good run-off.

Mike

 

[Mike800966]

Sikaflex is very good at sealing once its dried. So you could mass sikaflex a cover plate over all the holes and around the edges then "reconsider your position" as they say.
But a good thick cover plate 3mm? might be enough to get the aerial up out of the standing water which will evaporate or just drain away with time.
Regarding the ceiling, a lot of the boards are plastic coated to make them wipeable a cheap damp meter will need to penetrate the plastic and leave test marks . Consider how long the water was getting in before making holes!
Mike

Mike

 

[Gellyneck]

Gus-Lopez - can you tell me more about "the required 3mm gap"?

Pending our Spanish colleague gus-lopez getting out of his scratcher a gap of at least 3mm is required between the items being stuck together to give sufficient bonding by the adhesive. From memory, I packed our satellite dish mounting plate up by 5mm (a bit of scrap gas hose cut to 5mm lengths).

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