Gutter or silicon sealant?

[Matthew]

Somedays its just seems to be one thing after another since we moved into this new house. We had heavy rain last night and found the conservatory was leaking. Fortunatly it has a tile floor so no damage. It looks like some of the external rubber beading on the perspex roof has shrunk a bit (the conservatory is over 10 years old). I was going to fill the likely suspect areas with a couple of runs of clear silicon sealant. Is this the correct stuff to use? I noticed that unibond make a specific black coloured gutter sealant. Would this be any better or is it just black silicon?

Thanks, Matthew

[Grunff]

It's a bituminous, non-setting gloop. In some ways, it is superior to silicone in this type of application, because it stays put for a very long time. But it can't be smoothed down to a nice even finish as well as silicone.

[Bob Minchin]

The stuff I've got also says dont use on plastic (guttering!!) so it has stayed unused in the garage. Should be Ok on aluminium/glass joints but not on polycarbonate or UPVC.

Bob

[noelogara]

Dont use silicone to seal water out. It will look good but wont hold the water out. The tar is a much better option and you can buy in in a tube and apply like silicone carefully with a very small sharp cut, under the rubber seal, when bone dry and clean. It will last years. Do it in sunshine when the rubber will be soft. When silicone hardens the water will get under it and become unsightly and you will pull it out like a rubber band next year when you return to repair it.