I always told to store caravan by my servicing engineer nose high as water run off is alway towards the back as every caravan and Motorhome is designed for travelling in a forward manor so wind direction will always be pushing water to back end.
And Sealant is different to front end
If there’s any truth in that I don’t know but always worked a treat for m, and cos keep front cover on most times does stop steaks etc.
but use all year so not stood still. For to long
Store mine nose high, so excess water runs off the back, for simple reason that there are far more 'holes' in front, like 3 windows, front marker lights and gas locker, so more seals to potentially leak, and I don't want excess water flooding across A frame cowling and under the hitch cover onto stowed electrics plug, the ATC light and the handbrake, jockey wheel and hitch mechanisms. The price is a few black streaks down the back, but roof remains clear of debris and green slime, and the A frame stuff is always dry.
Store ours nose up as there are no windows at the back so little risk of leaks. Also store it level side to side so all the water does not constantly drain via the same route
I am with chrisn7 on this one with three windows and a sloping front the potential for water ingress is greater at the front than the back with no windows or seams plus the rear corners are vertical. I however also set a sideways cross fall so water is draining both sideways and rearwards rather than pooling behind rooflights etc. I have a fitted cover which covers all roof projections and keeps the van clean dry and free of mould and grime.
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