Floors
Insulating Floors Above Crawl Spaces and Basements
Houses of a certain age in California were built with crawl spaces. Many people don't visit their crawl spaces regularly to clean and treat them and so they become homes to vermin. They collect water and become the playground of molds and mildew and as such can contribute to a "sick house" syndrome where sensitive people end up ill all the time. AND, most floors are not insulated from whatever is in that crawl space. Understanding floor insulation in this case has everything to do with understanding that crawl space.
Remember: Even if you’re going to have someone else do the work for you, be informed. Watch the videos!
THE CRAWL SPACE
A healthy crawl space has plenty of ventilation, a slightly sloping floor from back to front, an access door, and a vapor barrier laid out over the dirt. It is regularly cleaned, the vapor barrier is checked for rips and repaired, the wall with its vents surrounding the space is checked, and sometimes, a pest control company sprays or sets traps for incidental vermin. And, finally, outside rain gutters have extensions on them to make sure the water isn’t draining under the house.
Sounds good, right? When I rented a house built in 1910, it had a crawl space of plain dirt. Someone had dug a storage area in it … which seemed like a good idea to me so I put luggage there … and the access was through a trap door in the house. The year came when my backyard flooded and the area under the house was completely submerged for weeks. Everything I’d put under the house was destroyed. I just chalked it up to my own stupidity. Looking back, I can’t recall the owner ever looking at that crawl space … and I remember the “sweet” smell of mildew hanging in the air.
Maybe you’ve had a similar experience. Or worse! So, understand that putting in insulation in your floor – which is do-able – might not solve the whole problem. You MAY have to solve the Crawl Space Health problem first.
I am not going to address that here. My purpose is to help everyone get ready for the heat and weird weather of Climate Change and so, I’m going to direct my attention to insulating a floor over a crawl space (or a drafty basement).
THE BASEMENT
Basements DO exist in California. However, we have been led to believe that they’re not ideal in a place that rocks and rolls with earthquakes.
Here’s a spot of history. If a house is on a concrete foundation and it shifts in a major earthquake, it may or may not scoot off of the platform. If the house has a crawl space and the house is up on cinder block pilings, chances are that a good shake will knock the house off its foundation causing a great deal of damage. A house built with a basement often survives best during an earthquake because it would have a very deeply set foundation. So, in reality, a house COULD be built with a basement but because “we’ve always built them on a flat foundation, we just keep building them that way.”
I’ve included a basement video for those of you who just went ahead and did things differently.
Do It Yourself Floor Insulation
Unconditioned Crawl Space
Here’s Owens Corning’s version of insulating a crawl space. Notice that she places the vapor barrier facing the floor. It is meant to reflect the heat back into the house, especially in cold climates.
(unconditioned space = no air conditioning or heat)
Exposed to the Elements
This gentleman uses Roxul, a stone wool combined with recycled slag. His batts are stiff and have an R28 value. He doesn’t need a vapor barrier because of the kind of insulation he’s using.
Insulated Vented Crawl Spaces
Johns Manville again.
Insulating Unvented Crawl Spaces
Finally, we have Johns Manville’s version of taking care of unvented crawl spaces with their products.
No Access to Crawl Space
Yikes! Here’s a job I’m glad I never had to do! In order to put in insulation, they had to tear up the floor ….. and put it all back down again.
Garage Conversion - Insulating the Floor
Love those Brits! Here we have a Garage (he says in his accent gair-azh in case you don’t quite get it) Conversion complete with an insulated floor. Lovely!
Floor Insulation
This company has an insulation which is laid on the floor as well. They’re from England. The insulation is called “heating insulation boards” but the boards themselves are NOT heated – it’s just that they help the room warm up (heat up) because the floors aren’t contributing to the cold. If you wanted to use this idea, you’d have to figure out what we have in the U.S. that’s comparable. It appears that the boards are already hard on the top, since they don’t describe laying down another “floor” on top of it.
Contractors - Key Words
Insulating a Crawl Space
R value …. vented ….. unvented….. insulation type….vapor barrier for floor …….