Someone here always seems to post a topic that I have an opinion on. Once again it has happened.
I am very opinionated regarding vinyl siding and older houses. I don't care for it! I feel that older construction has more character, I guess more of that "hand crafted" look. I cringe when I see an older home being clad with vinyl siding, hiding all the interesting wood trim and details.
That said...
When my house was renovated to it's present form in the later 1930's cedar shakes were the choice for the siding, stained of course. Well, we all know what that looks like after about 50 years of neglect. So in the 1970's the house was covered in aluminum siding, the older kind with no attempt at imitating wood texture at all. I almost didn't buy the place because of it.
When I enlarged the kitchen addition I went with cedar clapboards, this past summer I stripped a small part of the house to the sheathing and installed clapboards as well. I know I will never be able to do the whole house myself, hopefully at some point I will be able to afford to have the work done by (hard to type this) a.....contractor.
That said...
Make sure all the peeling paint is sanded off. The wood has to be really clean. It needs to be sanded, not just scraped. Bare wood is the best. If you paint over old paint with adhesion problems, the old paint will continue to peel off with your new topcoat stuck to it. The surface needs to absolutely dry. I prefer oil-based (alkyd) primers, but there are some high quality water-based primers that work well. A nice coat of primer and then 2 to 3 coats of paint and you're all set.
Pay the extra $$$ for premium paint, I prefer Benjamin Moore. After trying the cheaper brands I basically got what I paid for. B. Moore is like cream, nice and thick, it holds on the brush well. Cheap paint is watery.
Well, I stuck my 2 cents in!
By the way, my dad was a chemist at Vita-Var Paint Corp. in Newark, NJ, so I kinda grew up around the stuff. I still have cans of paint as old as around 1970 that are still good, a few cans of Vita-Lux Marine Spar Varnish that looks like it was made yesterday, Even a few cans of lead-based exterior house paint (TOXIC WASTE ALERT!!!).