# Replacing a roof vent/sky light - best sealant?



## bigtwin

I'm in the process of replacing the sky light in my van and have a few questions.

On removing the frame from the old unit, what's the best way of removing/cleaning up the old (black) mastic sealant?

I've bought a tube of Sikaflex 512; is this a good choice for sticking/sealing the new unit in?

Any hints or tips to aid the installation?

The reason I'm replacing the old unit? It blew off on the M42 North earlier today!  

Thanks in anticipation.

Ian


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## corkbuoy

This is recommended if you may need to remove the part in the future.
http://www.leisurebuy.co.uk/sika-sikalastomer-710.html


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## zappy61

I suppose the sikalstomer is reccomended but my choice would be the 512 in white. At least you won't loose it!

Graham


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## artona

I will be fitting another roofvent today and will use bedding mastic. Our vans roof is not flat so I use the bedding mastic to level the roof out before fitting the vent. The roof vent has a channel in the underside of it and into this goes the final run of mastic and then on it goes.

click here to see the product I am refering to

stew


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## JeanLuc

I refitted the smaller roof vent on ours last year using non-setting butyl mastic. Easier to use in a ribbon format as Stew says. Here is another supplier to choose from. (This is the online shop for Carafax who supply the caravan / motorhome builders). For "belt and braces" you could also go around the sealed edges afterwards with caravan sealant (it's similar to sikaflex but not designed as an adhesive). You will find that in the cartridge sealants section in the left hand menu of the website.

Carafax Mastic


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## Daedalas

Good Morning

I used Plumbers Mate ... it is superb. 

It sticks like the proverbial but is not setting and my builder friend uses it for sealing non pressure repairs to weeping household pipes.


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## bigtwin

Thanks all for the various suggestions.

I have now fitted the roof light using a form of tape sealant that Don Amott's (local Caravan/M'home dealer) people use - fingers crossed that it'll do the job! 

I managed to get all the old black mastic off with no more than white spirits.

Thanks again all.


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