The idea of exterior caulking for bulk water management just doesn't sit well with me. It's easy, and everyone does it, but it will eventually fail. The problem is that it sort of fails slowly, developing little cracks or pulling away from a corner in dry weather just a tiny bit. Then you sort of ignore it and pretend it's fine until it gets worse and worse and then finally you get motivated enough to recaulk. In the mean time, the gradually enlarging cracks and gaps have been not only letting water into your building envelope, but potentially trapping it in there.
So I'm on a mission to figure out a way to assemble all of my roofing, siding, and trim in such a way as to require no caulk. Well, at least not as a watershedding measure. I figure it's OK to airseal gaps to prevent drafts and such, and as a backup measure (such as damming against water traveling uphill). But that's neither herenothere.
One of the ideas I've had to do some of the things a less neurotic building would do with caulk is solventwelding. Solventcement for vinylbased products is readily available and very wellproven since it has been used for plumbing for decades. PVC pipes are slathered with a cement that is made up of PVC solids held in solution in a solvent bath. This goo softens the parent material such that when a pipe is inserted into a fitting, the liquid PVC of the pipe, fitting, and cement all mix together. Then, as the solvents evaporate everything hardens into one waterproof piece.
And the key idea here is that it is absolutely permanent. It's not like you need to hire a plumber every 20 years to crawl around under your house and reglue all your pipes. That's absurd, right?
So in this video I'm repairing the fascia that encircles my shed roof. It had a treerelated issue a few years back and I am finally getting around to fixing it properly. I'm taking the opportunity to film how I join the PVC trim material using solvent cement from the hardware store to create a welded seam.
I've never seen anyone do this before, and I can think of a few reasons it might not work as well as I hope, but I've been using this shed as a testbed for ideas like this to see how they perform. After three years in the weather I've had no issues with any of my old solventwelded joints, so I'm gaining confidence that this method may be worth considering for future builds.
Anyway, enjoy the video, and let me know in the comments what you think. Am I crazy? Is there something I'm missing; some reason this is a terrible idea and it'll all blow up in my face? Or am I a misunderstood genius, underappreciated in my own time, and this idea has changed your life forever?