Background
A couple of years ago the roof light/vent on my mothers caravan developed couple of leaks. The leaks were due to the plastic of the vent cracking. I carried out a temporary repair at the time applying Soudal FixAll sealant/adhesive to the damaged areas. This worked very well, however over the very severe late winter of 2018 a small leak was found and water had entered. The water did only cosmetic damage but as i knew the previous repair was temporary i decided to replace the roof light/vent as the cracking would only get worse due to the age of the plastic.
A complete new vent was purchased including the internal liner. Two tubes of sealant recommended by the manufacturer were also purchased. When the original leak was repaired a replacement vent including fitting was priced at GBP250. The replacement vent and sealant including delivery was GBP87, approximately one third of the fitted cost.
A complete new vent was purchased including the internal liner. Two tubes of sealant recommended by the manufacturer were also purchased. When the original leak was repaired a replacement vent including fitting was priced at GBP250. The replacement vent and sealant including delivery was GBP87, approximately one third of the fitted cost.
With the inner liner removed the extent of the damage due to the new leak was visible.
The damage was minor and not visible with the liner in place. Over the winter i had removed the liner so that on periodic visits any leaks would be easily spotted.
Having set up the ladder the first job was to remove the old roof vent. The plastic base of the vent was held in place with about 26 screws and a large amount of sealant.
When the vent was originally installed in the factory they were covered in sealant which stopped them from corroding over the years. As a result the screws were relatively easy to get out.
After all the screws were removed a craft knife was used to cut under the plastic base to separate it from the sealant.
With the roof vent removed the full extent of the damage to the internal roof structure could be seen.
Fortunately the damage was cosmetic. Due to the presence of the black mould the entire area was cleaned and treated with a bleach solution to kill off the mould and any spores.
The entire area around the vent was cleared of the remaining sealant and cleaned with wire wool to prepare for the new sealant.
The old sealant was very difficult to remove and great care had to be taken not to damage the aluminium sheet roofing.
After preparation of the roof vent opening the mating surface of the new vent was prepared with two continuous beads of sealant around the perimeter.
The roof vent opening was prepared with two separate beads of sealant and left for approximately 5 minutes .
The new roof vent was then carefully aligned and set in place.
Even pressure was applied around the perimeter of the roof vent to ensure the sealant was evenly spread. It was important to ensure that at least a couple of millimeters of sealant was left between the roof surface and the roof vent base to allow for movement due to temperature variations.
The original galvanised screws were replace with stainless steel equivalents
When all the screws had been secured trying to achieve as even a pressure as possible the sealant was smoothed out so as to allow waster to run off and not pool on the plastic base.
The sealant on the inside was smoothed where required so as not to stick to the liner when it was installed.
When the external work on the roof was completed the external weather cover was installed.
Fortunately the early summer of 2018 was very dry the new roof vent had time to bed in before it received its first Scottish downpour!.
The entire repair process took less than a day working at a steady pace and most importantly of all ensuring i did not fall off the ladder!
I did not install the inner liner for a couple of weeks so that i could check for any leaks after there had been some rain.
When i was sure the vent seal was water tight i installed the new inner liner and fly screen supplied with the new roof vent.