Manalto wrote:Thank you everyone for this discussion. I had been advised, with a tone of urgency no less, to embark on the expensive and difficult mission of creating a sealed space by someone who has been helpful in the past so I know his intentions were good, however misguided.
This person's advice may have been regional. What works for a similar house in North Dakota will have completely different rules for yours in Alabama (or Florida, or Arizona). That's why houses in particular areas have cellars or basements and others don't.
Houses were typically built with a certain logic for the climate, water table, etc. Trouble starts when a person attempts to apply some kind of universal rule like "OMG, seal it up tight!" that is not one size fits all. Good advice in one region can be terrible advice in another.
Yes, Willa, but the concept (the science behind the work) is the same everywhere. It just appears that it's difficult to understand for many, many people. I'm certainly not telling him to seal - only that you either have to do as complete a job at it as humanly possible, or not at all. That rule is solid. There is no hard and fast rule, you're correct. People seem to do what's easiest, really. Hopefully they take the factors into consideration before they make a move, that's all. I've worked on crawls and moisture problems for about 25 years...the problems always come from the same mistakes.
If you're in a region that has excessive humidity, soil that's far more damp than more northern climes (higher water table & precipitation level), no real need for 'warm floors', and different construction practices, like manalto's somewhat open pier design, then of course the rules change. It's difficult to get a truly sealed crawl. To what extent you should invest in doing so depends on your climate, of course. If the above apply, then vented would be called for. In NO case is PARTIAL venting, maybe combined with insulation and SOME sealing, ever wanted!! THAT is what causes you to see 'the jungle' up under crawlspaces with 25 different molds eating all the wood and so on. Has to be fully done, or not done at all. Just like an attic - the venting must be 'enough', and not too little. So, sorry Manalto - no floor insulation, ha ha.
NO basements were ever sealed in the past...but they didn't have moisture-trapping insulation either. They were generally fine until we came along with our more modern materials and started messing around.
I for one think that some form of humidity monitoring and control down there is essential (basement/crawl, not like manalto's 'outside' crawl) if you care about your home - that's where the sill rot, pests and other big problems starts, and it is VERY often due to insulation without consideration.
before I had my own cat I had some going under the stairs where it was sandy. to them it looked like a litterbox. I bought a bag of cayenne pepper and threw it in the sand, problem fixed.
