French drains are definitely a solid move, especially with those old stone basements. I’ve seen folks try to just seal up the inside, but that’s usually a band-aid at best—water always finds the weak spot. One thing I’d add: don’t skimp on the gravel layer or the fabric wrap around the pipe. If you do, you’ll be digging it up again in a few years when it clogs. Not fun. And yeah, it’s not cheap upfront, but compared to tearing out moldy drywall every spring? No contest.
Totally agree about the gravel and fabric—skimping there is asking for trouble. I learned that the hard way in my first house. Thought I could get away with just a thin layer of gravel, and, well, let’s just say the “French” part of my drain was more like “Paris in a flood” after two years. Ended up with a mini pond in the basement and a weekend spent cursing at mud-caked pipes.
One thing I’d toss in: if you’re in a spot where water’s really persistent, it can help to slope the gravel bed just a bit toward your sump pit or exit point. Not everyone does it, but it made a difference for me—less standing water, less smell. And yeah, sealing from the inside is like putting duct tape on a leaky boat. Works... until it doesn’t.
Funny how spending more up front saves you from spending every spring fixing the same mess. Live and learn, I guess.
Sloping the gravel is a good call—makes a difference, especially in older homes where nothing is quite level to begin with. I’ve found that even with the best drainage setup, if you don’t pay attention to the insulation around the foundation, you’re still going to get that damp, musty smell. Rigid foam boards on the exterior (if you can get to it) help a lot, but I know that’s not always possible with historic places.
One thing I learned the hard way: don’t use fiberglass batts anywhere near a wall that might get wet. They just turn into a soggy mess and hold onto the moisture. Closed-cell spray foam is pricey, but it’s saved me more than once—keeps the water out and doesn’t mold up. Not perfect, but better than tearing out soggy insulation every couple years.
And yeah, inside sealants are a band-aid at best. If water wants in, it’ll find a way. Sometimes you just have to accept a little imperfection and keep a dehumidifier running.
Honestly, I’ve had the same experience with fiberglass—once it gets wet, it’s game over.
Couldn’t agree more. I did the spray foam in my crawlspace last year and haven’t had that musty smell since. Curious if anyone’s tried those vapor barriers under the slab? I keep hearing mixed things about them.“Closed-cell spray foam is pricey, but it’s saved me more than once—keeps the water out and doesn’t mold up.”
Tried the vapor barrier under my 1920s place a few years back—mixed bag. Here’s what I noticed:
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“Curious if anyone’s tried those vapor barriers under the slab? I keep hearing mixed things about them.”
- If your slab’s already got cracks or isn’t perfectly level, moisture still finds a way up around the edges.
- In my case, it helped with humidity but didn’t totally kill the musty smell until I fixed some drainage outside.
- Honestly, nothing beats good grading and gutters for keeping water out in the first place.
- Spray foam’s great, but don’t skip the basics or you’re just masking bigger issues.
