for prep hobiekaw, clean and wash the roof- that’s it. i should mention you should peel your old rubber off. alsans needs a fairly solid surface to adhere to and work- alum, wood, concrete, metal, etc. my camper is an old one, ’89 and had an alum roof, it just needed old caulking scraped off and to be cleaned.
i’m not an rv tech, but if you want to talk roofs, i’m your man, 4th gen in this trade.
and ardvark is right, leaks rarely happen to the rubber or tpo unless there’s some physical damage done to it, like any roof, your house, the mall, your rv, 99% of all leaks occur in the details.
vents, a/c units, roof racks, stacks, any protusion threw the roof is where it almost always starts, and even with the tpo and epdm roofs on the newer units today, they STILL use caulking to seal these protusions to your rubber roof, or at the edges- which means constant matainence.
this is where alsans comes into play. this is not the “snow roof” junk you get at the rv shop, you will need to go to a dedicated roofing supplier for this, it is a 2 stage compound you mix that is light yrs ahead of caulking and eliminates it completely. and i mean any caulking or butyl, ya, we have hundreds of brands at work we use all the time and they are totally outclassed by PMMA. a similar compound to our PMMA is actually used for making fighter jet canopies.
if caulking was a 1950 chev with a stovebolt 6, alsans is a 2019 3500 D-Max
it applies to all the details on your roof, and you bring it right down onto all your side/fr/rr mouldings thereby completely wiping out any more caulk maintainece-forever….only downside i see is less work for rv shops on camper roofs…lol
we did a “floating” roof over a poop tank at the local sewage plant, first we put down a torch-on roof, then coated it with alsans because they have to pressure wash the “klinkers” off the roof every few days. in a month or so under that many pressure washings, the torch on membrane by itself would disintegrate.
the engineers on this job say at least a 30 yr life span under constant washings with the alsans. you can walk on it, even drive your car on it, we have water-proofed under ground parkades with it.
sounds way too good? the only catch, a 5 gal pail is about 250 clams and as far as i’m aware, RS 230 does’nt come in anything smaller…