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Posted: Feb 20, 2009 10:14 AM
costal house on pilings
My problem is 1st floor frozen tub trap and cold floors.
Before I go any further thier is the correct size insulation (pink)between enginered floor joist and closed off entirely with cement board.
This past fall ( after last years frozen trap) I checked and repaired all missing insulation and boxed in and insulated around the problem trap.
Then I put canned foam insulation between any cracks or small openings
around cement board. This area is 20 x 46. This did little help with this years cold temps. Trap still frozen and floors still cold.
I,m now thinking about a skirt insulated with foam around house. But I do get a foot 0r more of tidal water under the house offen. I do not think any type of insulation could withstand tidal water.The other option would be to foam the cement board inclosing exsisting pink insulation, perhaps 4 in closed cell.I just do not know if this (hanging foam)will last for long term and be guaranteed
Also house is located on edge of (The Great Marsh) wind and water is extreme.
Thanx Snider
mason
Posted: Feb 20, 2009 02:02 PM
Actually 2 lb density closed cell foam will repel water, so long as it is not there constantly and has a heavy head pressure. FEMA has designated 2 lb sprayfoam as the only insulation approved for under houses and in walls in severe flood prone areas. I have used it in floating docks.

Can you spray to the underside of the floor? That would insulate the first floor and seal it from the water.
Posted: Feb 20, 2009 04:15 PM
Do you mean to take down cementboard and pink insulation and exspose floorjoist and underside of 1st floor and then foam ?
I was hoping not to get into that tearout but to leave all as is, foam right over the existing cementboard.
thanx snider
quentin
Posted: Feb 20, 2009 05:16 PM
I would tear it out since you likely have moisture built up in the pink which means it has almost no real insulation value anymore and foaming it in would just trap the moisture for a mold haven. You will want to ensure you are not sealing in more problems for the future that would require you to tear it all off in a few years so it is best to do it right the first time.
Posted: Feb 20, 2009 06:29 PM
If I can aford the tearout and aplcation of 2lb density foam . How many inches of foam would you recomend ? Also would I put back any of the pink on top of foam and also cover all with the cementboard as it was? (This house was built 3 years ago.)
This is in reference to amount traped moisture in pink
Thanks for your input. snider.
Posted: Feb 21, 2009 09:27 AM
Hi Snider

Not quite sure where you are at, but we are in Louisiana if we can be of any help.


Steve
mason
Posted: Feb 21, 2009 03:43 PM
In Houston, I installed 3 inches to the underside of my mom's house, but probably 2 inches would work as well in that area. I would use more in colder climates.
quentin
Posted: Feb 21, 2009 04:28 PM
It looks like you are in New England if I get my google guess right. If so I would suggest you do 5 inches of CC and also cover any water lines down to the ground level or even a bit below and recover around them with the soil after. Beyond that, no using fiberblass since no matter what you do it will just soak more moisture back after. Also if the area is isolated from sinlight like it appears, you shouldn't really need to cover it with anything as it won't soak up any water. Just make sure the joists are all covered in a layer of foam as well to protect them and you should be fine.

Anyone else have ideas? Otherwise we do travel and I love spraying places like that since my hobby is cave crawling. You just tell us the demensions of the houseand I can give you a quote over the phone. Link at the right has our site if you wish to contact us.
Posted: Feb 21, 2009 06:27 PM
thanxs steve I'm in new england
Posted: Feb 21, 2009 06:30 PM
thanxs for the info

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