My 'helpful' bil has possibly ruined my camper

[snorepatrol]

I lent my bil our folding camper a few weeks ago and he told us to thank us he had done a treatment on the roof as there was a tiny bit of mould. (It was dead mould and was stains as opposed to mould) but anyway we said thanks and thought nothing of it.

So yesterday we're camping when a rain storm hits in the middle of the night and the entire roof of the folding camper is literally sopping wet and dripping onto us.
We find this out at 2am when we're practically swimming in our camper.

Turns out helpful bil has put his own home made cleaner all over the roof it's bicarbonate of soda as well as some other chemicals (I thought he'd bought a cleaner) so he's stripped the waterproof off the whole camper

We've never had leaks before and we are supposed to be going away again in a couple of weeks and the entire roof is basically just a big unwaterproof canvas now!

How can I fix this? Will a reproofing treatment fixed it or has my camper been ruined?

for you.
You can buy paint on waterproofing It used to be called Fabsil. I think Nikwax do a version now too. It comes in spray bottles or in a big bottle you paint on with a decorators brush, I think in this case the big bottle would be best.
Give it a good clean with a proper cleaner to make sure you've removed all his home remedy and then paint it on. Check the seals too. I would hope you can fix it.

Thank you I've found some Fabsil on eBay.
I'll make sure I buy some cleaner too I'll pull everything out and give it a really good rinse and clean and then start again.

I now need a sunny dry day over the next few days to open out the camper and let it dry as it went away soaking wet yesterday and I'm worried about mould.

I know bil was trying to be helpful but I'm a bit fed up about the damage his help has caused hopefully we can fix it though.

Is it your sisters husband or your husbands brother? Will you tell him?

It's my husbands brother. I'm not sure if I will say anything to be honest.

I know he will be mortified if he realises what he's done and offer to pay for the sealant and/or offer help as he's a pretty nice guy really as much as I could have throttled him at the time