Floor Insulation

Grady223 · 10-28-2009, 09:34 AM

Our island home is built on piers and the underside of the 1st floor is exposed. The floor was originally insulated with fiberglass insulation. We eventually tore it down as the critters were living in it and taking chunks away for their nests - a real mess.

Question for you all is - how do you recommend I replace it? Some suggestions I've gotten are fiberglass and plywood over it to protect it from the critters and cut and insert foam board insulation then insert it between the joists. Since it is an island home and only used May thru October - deep cold temperatures of Jan, Feb, etc. do not have to be considered.

Thanks

TomC · 10-28-2009, 10:16 AM

I closed in the bottom of my cabin with PT plywood on studwalls and insuated that. Whether you can do this easily/inexpensively or not depends on the grade and how high up on piers the house is built.A side benefit is that any pipes in this space are also kept warmer. Depending upon the moisture content of your soil, you may need to put down plastic as a vapor barrier, as well.

With a lockable hatch - it makes great storage space for tools and toys, too.

dpg · 10-28-2009, 10:21 AM

At home in Mass I had a sun room added on a few years ago, it is off the ground by about 3 feet. It's got Fiberglas insulation, then a layer of plastic sheeting buttoned up by plywood.

ishoot308 · 10-28-2009, 12:54 PM

I just did this to my camp and we used 1/4" luan and screwed strapping over every seam. We then used a urethane based caulking and caulked the strapping to the luan to ensure even the smallest critter could not get in. So far it has worked well.

Good Luck!

Dan

Bear Island South · 10-29-2009, 10:49 PM

I am looking into this: http://www.tigerfoam.com/

I will let you know how it turns out.

upthesaukee · 10-30-2009, 06:36 AM

Quote:

Originally Posted by Bear Island South

I am looking into this: http://www.tigerfoam.com/

I will let you know how it turns out.

Interesting reading. Note the FAQ's. Should be applied at temps around 70 or so, can be done down to around 55, below that it will not spray.

This has my attention for the crawl space under my house, but will have to wait until spring. May check to see if any dealers in the area use this.

RLW · 10-30-2009, 10:36 AM

Quote:

Originally Posted by Grady223

Our island home is built on piers and the underside of the 1st floor is exposed. The floor was originally insulated with fiberglass insulation. We eventually tore it down as the critters were living in it and taking chunks away for their nests - a real mess.

Question for you all is - how do you recommend I replace it? Some suggestions I've gotten are fiberglass and plywood over it to protect it from the critters and cut and insert foam board insulation then insert it between the joists. Since it is an island home and only used May thru October - deep cold temperatures of Jan, Feb, etc. do not have to be considered.

Thanks

May I ask why would you want to insulate it for those months only. I had a cottage that we used from first of April through into first of November and just used a wood stove to heat it on cold nights/mornings. Just don't walk around in your bare feet and wear a sweater.

ApS · 10-30-2009, 02:01 PM

Quote:

Originally Posted by RLW

"...May I ask why would you want to insulate it for those months only. I had a cottage that we used from first of April through into first of November and just used a wood stove to heat it on cold nights/mornings..."

To an island home, that's a lot of trekking of wood; however, you do have a valid point. What would be the pay-off point of insulating, then paying to protect the insulation? Also, I think a red squirrel would be able to chew through luan—PT plywood, not so easily.

Quote:

Originally Posted by RLW

"...Just don't walk around in your bare feet and wear a sweater..."

That's true, too—you'd be very cold from the waist down.

Bear Island South · 10-31-2009, 07:28 AM

Quote:

Originally Posted by upthesaukee

Interesting reading. Note the FAQ's. Should be applied at temps around 70 or so, can be done down to around 55, below that it will not spray.

This has my attention for the crawl space under my house, but will have to wait until spring. May check to see if any dealers in the area use this.

Thanks for pointing out the temps, looks like I am also waiting until spring.

ishoot308 · 10-31-2009, 01:46 PM

Quote:

Originally Posted by RLW

May I ask why would you want to insulate it for those months only. I had a cottage that we used from first of April through into first of November and just used a wood stove to heat it on cold nights/mornings. Just don't walk around in your bare feet and wear a sweater.

I can tell you that after we insulated our floor (walls and ceiling were already done) we noticed a huge difference in the dampness of the camp. Before the floors were insulated, everything such as bedding, clothes in closet, etc, etc, always had a damp feeling to it. Once we insulated and closed off the floor we no longer have this issue. I definitely think it's worth doing.

Dan

RLW · 10-31-2009, 02:27 PM

Quote:

Originally Posted by ishoot308

I can tell you that after we insulated our floor (walls and ceiling were already done) we noticed a huge difference in the dampness of the camp. Before the floors were insulated, everything such as bedding, clothes in closet, etc, etc, always had a damp feeling to it. Once we insulated and closed off the floor we no longer have this issue. I definitely think it's worth doing.

Dan

Are you saying that the insulation is collecting the moisture/dampness. If that is the case then something in wrong. A vapor barrier is suppose to do that. Insulation is to stop air flow from below and/or outside not to stop dampness. Insulation is not suppose to get wet as that causes many other problems. Just my little ole 2¢ worth.

ishoot308 · 10-31-2009, 03:37 PM

Quote:

Originally Posted by RLW

Are you saying that the insulation is collecting the moisture/dampness. If that is the case then something in wrong. A vapor barrier is suppose to do that. Insulation is to stop air flow from below and/or outside not to stop dampness. Insulation is not suppose to get wet as that causes many other problems. Just my little ole 2¢ worth.

No, what I am saying is that by sealing off the bottom of the floors with luan and fully sealing all seams after insulating , it certainly seems to have stopped the flow of the damp ground air into the house. It also stopped ants and other pesky critters from entering the house through the floor. Could this have been accomplished without the insulation...I suppose, but insulation is cheap and easy to carry out to the island so why not have warm floors as well?

All I can say is we are extremely happy we did it. Your mileage may vary...

Dan

10-28-2009, 09:34 AM	#1
Grady223 Senior Member Join Date: Apr 2004 Location: New Hope, PA & Barndoor Island Posts: 465 Thanks: 93 Thanked 24 Times in 18 Posts	Floor Insulation Our island home is built on piers and the underside of the 1st floor is exposed. The floor was originally insulated with fiberglass insulation. We eventually tore it down as the critters were living in it and taking chunks away for their nests - a real mess. Question for you all is - how do you recommend I replace it? Some suggestions I've gotten are fiberglass and plywood over it to protect it from the critters and cut and insert foam board insulation then insert it between the joists. Since it is an island home and only used May thru October - deep cold temperatures of Jan, Feb, etc. do not have to be considered. Thanks

10-28-2009, 10:16 AM	#2
TomC Senior Member Join Date: Apr 2004 Location: Lakes Region Posts: 818 Thanks: 42 Thanked 185 Times in 116 Posts	Close in the bottom? I closed in the bottom of my cabin with PT plywood on studwalls and insuated that. Whether you can do this easily/inexpensively or not depends on the grade and how high up on piers the house is built.A side benefit is that any pipes in this space are also kept warmer. Depending upon the moisture content of your soil, you may need to put down plastic as a vapor barrier, as well. With a lockable hatch - it makes great storage space for tools and toys, too.

10-29-2009, 10:49 PM	#5
Bear Island South Senior Member Join Date: Apr 2008 Location: Southboro, MA Posts: 579 Thanks: 75 Thanked 384 Times in 170 Posts	Tiger Foam I am looking into this: http://www.tigerfoam.com/ I will let you know how it turns out.

The Following User Says Thank You to TomC For This Useful Post:
Rattlesnake Guy (10-28-2009)

10-28-2009, 10:21 AM	#3
dpg Senior Member Join Date: Apr 2004 Posts: 2,624 Thanks: 157 Thanked 236 Times in 173 Posts	At home in Mass I had a sun room added on a few years ago, it is off the ground by about 3 feet. It's got Fiberglas insulation, then a layer of plastic sheeting buttoned up by plywood.

10-28-2009, 12:54 PM	#4
ishoot308 Senior Member Join Date: Feb 2008 Location: Gilford, NH / Welch Island Posts: 6,535 Thanks: 2,455 Thanked 5,468 Times in 2,143 Posts	I just did this to my camp and we used 1/4" luan and screwed strapping over every seam. We then used a urethane based caulking and caulked the strapping to the luan to ensure even the smallest critter could not get in. So far it has worked well. Good Luck! Dan

The Following 3 Users Say Thank You to Bear Island South For This Useful Post:
Grady223 (10-30-2009), Rattlesnake Guy (10-31-2009), upthesaukee (10-30-2009)