Best method to resolve small leak on rooflight

[YoungDave]

Hi everybody,

We have a slow leak on the large over-dinette rooflight on our 2002 hymer camp swing.

I've had a look and there is some mastic around the exterior joint that has degraded.

Looking for any feedback on best steps to resolve this. I am weighing between:

1. Remove brittle / failed mastic bead. Clean up and replace with a fresh bead of sealant.
2. Remove entire skylight. Clean up both skylight and roof, refit.
3. Replace skylight.

Factors I'm thinking about:

• My inclination is to try option 1 and hope that this is enough. If this is a fix for a few years, that's okay for now. However if this is a waste of time, I'd rather not bother (as it will just make option 2 or 3 a bigger job).
• If removal is required. The roof light is ~25 years old. Might it crack on trying to remove and need replacing. If so do I need to have a replacement on hand before attempting the removal.
• If the current roof light is (presumably) covered in mastic, is it even possible to clean to a standard that it can be resealed.

Would love to hear any perspectives / experience here.

 

[Al-Di]

Remove clean reseal.carefully

 

[CazPaul]

No 2 for sure

 

[activecampers]

Remove clean reseal.carefully

This. And use non settings mastic, not silicone.

If you bodge it, it will likely be temporary

Gently, palette knife/metal ruler etc

 

[Emmit]

No.2 Every time.

 

[Just smiffy]

I would see the availability of a replacement before you do anything, 2, would be my option but with a replacement that I could get fairly quickly. Do it before winter sets in….

 

[CORNHYM]

I have exactly the same problem with the same skylight. I've tried sealing areas around it with no success so I will end up taking the whole thing off . There are many screws around it and I've noticed that water tends to pool around the skylight on my van and so in the meantime when parked up I tilt the van slightly so as the water can run off.
There is a rubber washer in the winder which can wear and leak and so I've got a mixed pack of sizes off ebay ready for replacement and also four star lock washers ready to replace for the four corners ones when taking perspex off which I believe are a pig to get back on and off so as not to crack the perspex. Best of luck.

 

[scotjimland]

No 2
Removed and resealed one on my 2001 Hymer b644..

No 3
my window was so old it cracked and I had to replace it, complete with a new rubber seal ..
expensive repair, window £248 . aperture seal £38
.. from Brownhills

doing anything else will just be a bodge

 

[CeeJay13]

This. And use non settings mastic, not silicone.

Any suggestions as to which one?

 

[Landy Andy]

No. 2, might turn into No. 3, if it fails due to age. But if it needs doing. Do it properly

 

[CazPaul]

Any suggestions as to which one?

Hodgsons seamseal CV

 

[EssexBoy]

I had a similar issue, but if was caused by water pooling around the skylight...

In the end, I did no.2 on your list, but also had to build a "defensive wall" from 50mm x 8mm flat UPVC that i Sika'd down permanently just outside the perimeter of the skylight. This has stopped any pooling water from getting anywhere near to the skylight...

 

[Carpmart]

Another vote for #2

 

[activecampers]

Any suggestions as to which one?

personally I use Dekaseal 8936
Not the cheapest, but used by some pro's.
I have it on my windows and 3x skylights - and been perfect so far and is still pliable - it never sets solid.
Its great as you can be as messy as you like, its not like silicone, whack on loads in a single fat bead and let it ooze out. Panic, but its fine! Use a credit card (dabbed in white spirit) to mark/score the edges of the ooze, grab a ball of dekaseal, and it "dabs off" just like bluetack and leaves no residue. Some YouTube examples/demos.

If you have a PVC roof get some infills from ebay. Also on mine I made a "dam" in the indents with a PU (stixall) UP TO but not under the skylight. This goes solid (its bonding) but then with dekaseal up o and oozing over you get a solid extenal seal and a flexible seal to the skylight.

My top tip too, is if skylight is out, use some aluminium tape to seal up any gaps around the skylight. On mine as I installed from scratch I bonded wood and then silver tape after so no holes anywhere. Why? So WHEN it leaks (not if, its only a matter of time!) water will ONLY be able to drip out of the skylight rather than track to a random place in the van causing untold damage.

Skylights will leak at somepoint, its life.

Don't always follow pros - my first "pro" van build leaked after 4 years or so, and they said "hey - use non setting mastic" - great - but they on build used PU bonding that made it impossible to remove the skylights! (well, was possible but vvvv tough and took the paint off the roof - I wasn't happy)

 

[activecampers]

I had a similar issue, but if was caused by water pooling around the skylight...

In the end, I did no.2 on your list, but also had to build a "defensive wall" from 50mm x 5mm flat UPVC that i Sika'd down permanently just outside the perimeter of the skylight. This has stopped any pooling water from getting anywhere near to the skylight...

snap. Great minds. Thats fine do to with Sika/PU/bonding as thats permanent, then non setting stuff on the skylight overlapping the dam.

Thought I was the only one who thought of this!

 

[EssexBoy]

snap. Great minds. Thats fine do to with Sika/PU/bonding as thats permanent, then non setting stuff on the skylight overlapping the dam.

Thought I was the only one who thought of this!

Yep... non setting on the fix of the skylight, then filled the gap between wall and skylight

 

[Barchetta47]

I took our large roof-light out to do a No 2 as above. It’s the original on a 2004 Burstner. In taking it off as gently as possible it still developed a hairline crack. I didn’t see the very small crack until I’d refitted it!!! In the end I over laid the crack with Sikaflex 522 and it’s been okay for a couple of years.

As others have said might be worth checking if you can get a replacement. Good luck and be patient!

 

[TerryL]

If disaster should overtake you, and it cracks, provided you've got all the bits there is a company that will make you a new one - name slips the mind at the moment, but someone here will know it.