Yeah, mineral wool’s definitely a step up from sheep’s wool in damp crawlspaces. I’d add that if you’ve got older pipes, double-check for rust or corrosion before wrapping—trapped moisture can speed that up. I’ve seen folks skip that and regret it later. Layering’s key, but don’t forget airflow if you can manage it... helps a ton with the funk.
I’ve seen that too—people just slap insulation on without checking the pipe condition first, and then wonder why they’ve got leaks a year later. Curious if anyone’s tried using vapor barriers in crawlspaces along with mineral wool? I’ve read mixed things about whether it actually helps or just traps more moisture.
Curious if anyone’s tried using vapor barriers in crawlspaces along with mineral wool? I’ve read mixed things about whether it actually helps or just traps more moisture.
Vapor barriers in crawlspaces are a bit of a double-edged sword, honestly. If you install them right—sealed edges, no rips, and proper overlap—they can make a huge difference in keeping moisture out of the insulation and off your pipes. But if you cut corners or the crawlspace already has a moisture problem, yeah, you’re just locking that damp air in and making it worse.
Mineral wool’s great for resisting mold, but it won’t stop water vapor by itself. I’ve seen setups where folks put mineral wool between joists and then a 6-mil poly vapor barrier over the dirt floor, taped up the seams, and ran it up the walls a bit. That worked well, but only because they fixed drainage issues outside first. If you skip that step, you’re asking for trouble.
Bottom line: vapor barriers can help, but only if you address the source of moisture first. Otherwise, you’re just hiding the problem until it gets bigger.
That worked well, but only because they fixed drainage issues outside first. If you skip that step, you’re asking for trouble.
I’ve definitely seen the “just hiding the problem until it gets bigger” thing happen. My neighbor slapped down a vapor barrier without checking his gutters or grading first—next spring, he had a mini swamp under there and a smell that could knock you over. Mineral wool’s tough, but it’s not magic. If you’re gonna go the vapor barrier route, make sure you’re not just gift-wrapping your crawlspace for mold.
Yeah, I’ve seen that movie too—“The Revenge of the Funky Crawlspace.” It’s wild how folks ignore the basics like gutters and slope outside. You can throw all the fancy stuff under your house, but if water’s still sneaking in, you’re just marinating your pipes and insulation.