Damp from Swift caravan roof joints

[Metaland Ale]

I have a Swift Challenger Sport 636 permanently sited near Chapel St Leonards.
I noticed discolouration on the roof inside the caravan.
When I inspected the roof, both joints were damaged and spongy.
The white tape (apparently used for cosmetic purposes) was blistered and bent and damaged.
The joints run across the caravan from one side to the other - one at the front and one at the back.
Can anyone tell me the best way to deal with this, please?
Can I get away with running a strip of 4 inch wide rubber tape over each joint?
How big a job is it to dig out the sealant and replace it?
Do I need to call out a mobile repairer and how much approx will that cost?
I would welcome any advice.
Thanks.

 

[Buckman]

I have a Swift Challenger Sport 636 permanently sited near Chapel St Leonards.
I noticed discolouration on the roof inside the caravan.
When I inspected the roof, both joints were damaged and spongy.
The white tape (apparently used for cosmetic purposes) was blistered and bent and damaged.
The joints run across the caravan from one side to the other - one at the front and one at the back.
Can anyone tell me the best way to deal with this, please?
Can I get away with running a strip of 4 inch wide rubber tape over each joint?
How big a job is it to dig out the sealant and replace it?
Do I need to call out a mobile repairer and how much approx will that cost?
I would welcome any advice.
Thanks.

I would strongly suggest a mobile technician as soon as possible. I probably needs to be dried first as covering with tape or similar will keep in the damp.