need advice: how to insulate below floor on addition
 

Hello All,

I bought a home that has an addition which is built on concrete
pillars, much like a deck would be. The builder put fiberglass
insulation between the floor joists, and it just fell out onto the
ground (brilliant, eh?).

The room is cold in winter and hot in summer, and I need advice on how
to better insulate the floor.

I was planning on putting new fiberglass insulation between the joists,
then covering it with foam sheet insulation. I don't know if this will
make it any better or worse, but I am at a loss as to what to do here.

Any comments, advice appreciated.

-KJ

The foam sheet needs to be covered since it is flamable.


wrote in message
oups.com...
Hello All,

I bought a home that has an addition which is built on concrete
pillars, much like a deck would be. The builder put fiberglass
insulation between the floor joists, and it just fell out onto the
ground (brilliant, eh?).

The room is cold in winter and hot in summer, and I need advice on how
to better insulate the floor.

I was planning on putting new fiberglass insulation between the joists,
then covering it with foam sheet insulation. I don't know if this will
make it any better or worse, but I am at a loss as to what to do here.

Any comments, advice appreciated.

-KJ

On 27 Apr 2005 21:18:44 -0700, wrote:

I bought a home that has an addition which is built on concrete
pillars, much like a deck would be. The builder put fiberglass
insulation between the floor joists, and it just fell out onto the
ground (brilliant, eh?).
As discussed, chicken wire will work. There also used to be what I
was brought up to call "tiger teeth"---springy pointed single wires
about the diameter of the bottom of a wire clothes hanger. One just
popped them up between joists and they spring loaded themsleves and
held the insulation in place. I used them in my current house 20+
years ago and they are still there. You could ask at a hardware
store, or call an insulator and ask.

"Roy Starrin" wrote in message
...
On 27 Apr 2005 21:18:44 -0700, wrote:

I bought a home that has an addition which is built on concrete
pillars, much like a deck would be. The builder put fiberglass
insulation between the floor joists, and it just fell out onto the
ground (brilliant, eh?).
As discussed, chicken wire will work. There also used to be what I
was brought up to call "tiger teeth"---springy pointed single wires
about the diameter of the bottom of a wire clothes hanger. One just
popped them up between joists and they spring loaded themsleves and
held the insulation in place. I used them in my current house 20+
years ago and they are still there. You could ask at a hardware
store, or call an insulator and ask.

HD sells two lengths of the wire or you could make them yourself.

I would replace the insulation, then staple plastic over it and then
use treated plywood to cover over that. I would worry about insects
and rodents if it is not "sealed" (but I also do not know how it is
protected from the outside).

Roy Starrin wrote:

wrote:

I bought a home that has an addition which is built on concrete
pillars, much like a deck would be. The builder put fiberglass
insulation between the floor joists, and it just fell out onto the
ground (brilliant, eh?).

As discussed, chicken wire will work...

So would foil, for downward heatflow, eg thin double-foil foamboard
with no other insulation.

Nick

So just nail foamboarn to the (ground-facing) edge of the joists - or
to the underside of the floor?

wrote:

So just nail foamboarn to the (ground-facing) edge of the joists - or
to the underside of the floor?

Sure. Warm air rises, so we only need to reduce heat loss by radiation.

Nick

Where do you live , what Zone, what are winter temp lows. This will
determine what you need to do.

Upstate NY. Winter temp lows here hit about -13F