How can I correct a subfloor that is insulated with the kraft paper facing the dirt in my crawl space?

Question

I don't want to remove it and flip it around as the crawl space is very tight and this would be almost impossible.

Also, the side facing the ground has a lyaer of plastic vapor barrier, so any water spilled on the floor from inside will essentially leak through, drench the firbergalss and collect on top of the plastic.

I was considering istalling a layer of felt paper(would kraft paper be better?) on top of the subfloor before installing hardwood tongue and groove. would this help or just add to the problem by vapor locking the whole thing?

Please help!!!

Answer 1

I know vapor barrier on the heat side however this is a floor I would take a razor knife and slit the plastic and kraft paper right down the middle and leave it that way no vapor barrier

Answer 2

Cut out the bad sub floor from the top. Removed it and replace with good sub floor material. Replace paper under sub floor area that is effected. Be sure you overlap it with about 12" on each side and tape it in place. If the plastic vapor barrier gets cut while removing the sub floor the same method should be used as in the Kraft paper.

Now you can use an additional vapor barrier under the new wood floor. See manufactures recommended procedure for this step.

All manufactures of wood recommend different products for the protection of there wood.

Best of luck

Answer 3

Personally I would have installed the vapor barrier down toward the crawl space also. You have to remember you are more likely to permeate moisture up from the crawlspace than down from above. I know you are always supposed to install vapor barrier towards the heat source, however in the case of crawl spaces, I have always reversed it as the crawl always seems to have more moisture in it.

Unless you plan on having frequent spills on the main floor- I would not be concerned about spills leaking through the floor and into the insulation. I would lay some red rosin paper down prior to installing the hardwood floor.

Don't make an insignificant matter an overblown headache-

Your insulation will be fine, and so will your new floor.

Answer 4

The sub floor material used today is resin reinforced, and makes an effective vapor barrier.  Unless your home was built in the 50's (possibly 60's) you likely have this material, not the diagonal tongue and groove decking used back then.  So leaking through should not be a problem.  

Also, you should have a poly vapor barrier covering the ground to prevent moisture from migrating to your structure.  

So while a vapor barrier attached to your insulation is unusual and not a preferred application, I would not defeat the existing vapor barrier unless you have the earth covered with a poly film.

Answer 5

In a crawl space the paper side is supposed to face the dirt! that is the side where moisture will likely try to enter the insulation. red rosin paper would be the correct product to use for the Hardwood flooring.