leaky westy hightop roof

[thebogman]

Help needed leak experts!

Been parking the van (t25 california westy high top) on a slope nose pointed up hill, and noticed a bit of water leaking into the back and it's pooling on the boot lid..

Not coming from tailgate itself, coming from small gaps in roof seam just inside the tailgate on each side. This is where the drip is coming from.
Right:

Left:


Anyone know wheres a likely place to start looking for the source of the leak?
I have already resealed the lip at the back outside where the figerglass roof meets the van but think the water might be coming in from further up the van.

After I resealed the rear lip I poured a few watering cans over the entire tailgate, rear roof and there were no leaks. However as soon as it starts raining again the drips start. I figure the water is getting in somewhere further up the van.. Any ideas where to start looking? Skylight seals on very top of roof look ok from visual inspection...

Where to start the troubleshooting?

(edited broken image tags thanks 1664)

[1664]

[AdrianC]

Exactly the same place as I've got water ingress... But that's some nasty looking rust that's resulted for you.

First off, are you ever seeing drips on the roof skylight frames? If so, rule them out by taking them out and re-sealing. That reduced ours, but didn't cure it.

I _think_ the main source for us is inside the valley above the tailgate. It's difficult to see with the tailgate on, but the hightop has a lip which rivets to the main body along there. I think it's getting past that - I need to remove the tailgate, give it all a really good clean and seal. In the interim, I've put some gaffer tape over the joins, and it's now sit back and wait for the rain...

With that rust, though, I think you need to start considering whether there's some rot in the roof itself that you're not seeing. Might be top-off time soon for investigation.

[thebogman]

I think the rust looks worse in the pics than it actually is, seems to be just surface rust (i hope) never can tell till you go grinding!

Due to the "westy lean" the left of the van sits is a bit lower than the right and most of the water comes in that side. Hence more rust on the left I assume
However when theres heavy rain there's a steady drip from both little gaps left and right.

I had a good visual inspection of the valley above the tailgate and it seems to be nicely sealed there, also kind of ruled that out because it doesn't drip when I sprayed a lot of water there.
Might follow your advise and remove tailgate and reseal next time I get a chance though to make sure.

[AdrianC]

Due to the "westy lean" the left of the van sits is a bit lower than the right and most of the water comes in that side. Hence more rust on the left I assume
However when theres heavy rain there's a steady drip from both little gaps left and right.

Ours is worse on the right, no surface rust visible (yet...?)

[clift_d]

To re-iterate - skylights are a good place to look. We had a drip by the A-pillar on the drivers side that hopefully has been resolved by taking out and re-fitting the front skylight.

bootie3367 put some images up of the process in the What did you do to your T25 today? thread. Mine was pretty much as they found theirs. Roughly half the fixings holding it in place had completely corroded through and the timber frame around the opening was completely rotten and needed replacing. I used Sikaflex 512 to seal up after.

https://club8090.co.uk/forum/viewtopic.p ... 4#p7837334" onclick="window.open(this.href);return false;

[thebogman]

Ah.. I see

I had just checked the external sealant and it looked good but will have a look closer up there too. Thanks!

[AdrianC]

Roughly half the fixings holding it in place had completely corroded through and the timber frame around the opening was completely rotten and needed replacing. I used Sikaflex 512 to seal up after.

Mine weren't quite that bad, but the old sealant was definitely dead. The screws were badly rusted, but all intact, and the wood was a bit manky but not enough to warrant replacement.

From inside, take the caps off the screws - including the handle - and undo everything. The inner just pulls off downwards, then the outer pulls off the top - that simple.

Another possible leak source - there's a plastic screw in each corner of the hightop for the surf etc racks. Take them out (if they will...), sealant in the threads, then screw them back in. They'll be there for life, but...

The front window can't leak into the structure - it's only single-skinned there. Any leak will be immediately visible inside.

[weimarbus]

I have had a leak there in the past on my camper and traced it to where the tailgate hinges are bolted to the main body, make sure that these screws are tight and run a bead of sealant across the protruding part of the hinge where it meets the main body. HTH

[DavidPallister]

Check the sealant along the length of the gutters as well as above the tailgate, the fibre glass roof is bonded down in the gutters and the sealant brakes down along here and lets water in.

[Plasticman]

also consider that condensation very happily forms on the insides of the fibreglass roof and runs down which is a major cause of this
mm

[thebogman]

Pulled the two inner seals and plastic covers off the skylights at the weekend and everything seemed nice and dry up there, fiberglass all dry, wood not rotten, only a minor bit of rust on the screws..
Didn't disturb the outer seal as I assume if it was leaking up there the fiberglass and wood would be all manky...

The leak search continues, must be on the gutters methinks.. Dreading that job..