I'm going to be painting my house built in 1997 (bought last fall; in Pac NW; previous owner did no exterior maintenance). The exterior of the first floor has lap siding (I'm pretty sure it's just cheap wood, not a composite). More on this later. I'm somewhat competent on interior things (as long as it's not structural, but am afraid of making things worse on the exterior.
On the 2nd floor, the outside has LP 4x8 siding. This hopefully is not the garbage they were manufacturing through 1995, although it could be if the builder bought up old stuff. It has strips of wood spaced vertically about every 18", which cover the seams of the sheets. The caulking along those seams is in pretty good condition (although I haven't gotten out the extension ladder & looked at the top half yet).
Horizonally, along the bottom edge of the sheets there is an 8 x 1 board covering the bottom seam.
On the side of my house with a southern exposure, the caulk between the 4 x 8 sheet (2nd story) & this 8 x 1 board has clearly failed, so I recaulked that (and will be checking it annually). Unfortunately, I took the advice of a HD associate (I know better!) & probably used too low a quality of caulk for half of it (DAP's Alex Plus). I'm going to switch to the DAP Ultra 230 (anyone have other suggestions?) - I tried some of the Quad caulk, but that stuff is just awful to work with. One question: Should I have primed under the caulk? Some caulks say it isn't necessary; the DAP stuff didn't say. I assumed I wanted the caulk to adhere to bare wood, but some here seem to advice priming and then caulking. I can't see any signs of water damage (expanding wood) on the bottom of the sheets, although the 1 x 8 board could be hiding something).
Now to the caulk along the vertical strips of wood (2nd story): I'd like to re-caulk those, even though most of the caulk is in good shape because I'm worried (with good reason; see below) about water penetration. Since this is 2nd story, I really don't want to dig out the existing caulk - can I just caulk over that if I use a heavy enough bead? I know it's usually better to dig out the existing caulk, but it would take forever, not to mention involving precarious ladder work (I will be getting a stabilizer for ladder), except maybe it's not better if I damage the surface of the sheet (sheet is made of OSB))
I can see rust around some of the nails they used to attach the LP sheets. How do I deal with that? Will Zinsser Bullseye 1-2-3 cover? A rustoleum paint? Caulk? I don't care as much about simple discoloration; I'm more concerned about water intrusion or nail failure.
The paint on the (first floor) lap siding on all but the south side of the house seems in pretty good shape. The south side has some flaking, so I scraped off that pretty well. I mentioned the wood lap siding was cheap - lots of knots & some horizonal cracks around nails (& a few cases of the wood completely splitting around the nail). A lot of the paint flaking occurred around knots & these horizontal cracks. Question: Is the Zinsser 1-2-3 primer ok to use over the knots & other bare wood (most knots are 1" in diameter or less).
Question: There are a few places in the lap siding where the knots have fallen out - what's the best thing to fill these spaces with? I was going to use caulk, but as I read this site, came across advice against that. What about filling dimples (<1/8") caused by nails? What about for filling those horizontal cracks?
The lap siding is really loose - in some places I can pull the lap siding away from the house. Question: Should I nail down the loose lap siding? I'm guessing I should (if yes, what kind of nails? galvanized? (do they make galvanized ring shank, which I assume would hold better). The only reason why I'm doubting is whether that will simply hold water in (but the loose laps are probably letting in water.) Under the lap siding is some kind of house wrap (definitely not Tyvek because I can see it's made of plastic fibers that run horizontally & vertically, with a plastic layer tying the fibers all together). Under the house wrap is OSB. I'm pretty sure they did include a "furring gap" between the siding & the house wrap, which from reading several PDFs people have posted, is now advised.
Luckily, the house has only 7 windows. Under the window on the south side (most sun exposure), part of the apron had dry rot to the point of me being able to simply break out a piece. The sill extends only about 1/2" beyond the window, & does not slope down. I can tell the OSB under the right half of the window has been compromised - when I press on it, it is soft. (I also cut out a piece of sheetrock on the interior side - the OSB is not crumbling but when you touch it from the interior, it is soft). (No sign of flashing around window; I didn't remove housewrap so cannot be sure, but I really doubt it, given one of the PDFs posted here about building practices of the era my house was built.)
I fear I may have to replace some OSB but cannot afford that expense this year (perhaps next). When I look at the bottom corner of this side of the house (about 5 feet to the left of the window), I can tell the OSB there is deteriorating just by feeling under the wood board that goes from the bottom of the lap siding & covers the mudsill (house has a crawl space with poured contrete walls). There is a 3" wide board that runs vertically on each corner of the house. The caulk between that & the wood lap siding had failed on the south side of the house, so that may be where water is getting in. I hope that's it because if it's not, it's getting in though the wood lap siding or (2nd floor) LP panels.
As I said, I'm already resigned to having to at least partially reside the south-face down the road. However, I am hoping I can seal it up well enough to minimize damage for the next year. I'm well aware that once the siding is removed, I could discover extensive damage & that I cannot put off doing this for too long.
For paint, I'm planning on using Sherwin - Williams. I am debating whether I should use Duration on the south exposure & SuperPaint on the rest. I'm wondering whether Duration will provide additional protection against possible moisture intrusion? (the guy at S/W said with Duration, I just need to get adequate paint thickness - and I could do that by applying multiple coats).
Also, what about cleaning the siding before painting? I'd like to use something fairly environmentally friendly if possible - thus, avoid bleach. The siding is not noticeably dirty, just a bit dusty. S/W has Simple Green for cleaning siding. The guy there also said "just use soap & bleach". I also know there's Jomax that some here recommend - it looks a little less friendly (environmentally), but if it will magically cause the paint to adhere much better, I'd consider it. I'm just going to use a bristle brush & scrub - I got a hose fitting that says it delivers up to 200 PSI, but given the issues with my siding, I figure using a gentle hose to simply wet down & rinse off whatever cleaning solution I use.
I'll be painting with a roller, following quickly with a brush! At least 2 coats. I'm seriously considering priming the whole house (Zinsser Bullseye 1-2-3??), although it seems from comments here that isn't really necessary except where there's caulk/bare wood. Would it give me an added margin of protection against moisture intrusion? If yes, I'd seriously consider it.
Suffice it to say, the builder did the absolute minimum, & 10+ years of no exterior maintenance did not help. (I am counting my lucky stars the house wasn't built a few years earlier.) Many homeowners likely wouldn't have started digging the way I did, & may not have discovered these problems for a while - I unfortunately have a habit of exploring too much.