Leak in roof lantern

Jupiter01 · 14 Feb 2026

I’ve had one of these in place for 10 years

It was dripping inside along this rafter (marked in red):

I had a look at the rubber seal and they seem fine but noticed that there is a slight gap at the top of the rafter here. There also seems to be some residue:

I can see this residue on other joins too:

Why type of sealant/adhesive is this likely to be and does it need to be resealed after 10 years?

I’d appreciate your advice on this.

Jupiter01 · 27 Feb 2026

Any thoughts on the above would be gratefully received. Thanks in advance.

Jupiter01 · 22 Apr 2026

Hi, sorry to push this again but I would be grateful for your advice with this.

ronniecabers · 23 Apr 2026

Clean it up with something like white cif (.dont use the yellow it will stain ) , then apply a beading of white silicone where white trims meet white trims , and clear silicone in other locations you fear it might be leaking

Jupiter01 · 23 Apr 2026

ronniecabers said:
Clean it up with something like white cif (.dont use the yellow it will stain ) , then apply a beading of white silicone where white trims meet white trims , and clear silicone in other locations you fear it might be leaking

Thanks for that. Much appreciated.
Should I be using a certain type/brand of sealant? I assume CT1 is not suitable for this?

ronniecabers · 23 Apr 2026

Id stick to a Low Modulus neutral cure , usually as LMN on the tube , the only real stipulation

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Leak in roof lantern

Jupiter01

Jupiter01

Jupiter01

ronniecabers

Jupiter01

ronniecabers

DIYnot Local

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