I want to insulate the bottom of the floor (inside crawlspace). The problem
is the floor joists are nowhere near 16" on center. My single story 1000SF
house is built on a deck like subfloor. It is made up of 4x8 beams running
the length of the house set 4 feet apart with 2x8 tongue and grooved planks
set perpendicular. The result is a thick solid floor with few beams
underneith.

To put it another way, the floor joists are 4 feet apart and the crawlspace
access is a 2'x2" hole in the closet floor.

I was considering 4x8 sheets of solid core insulating panels cut in half the
long way but this would be expensive and would not have as good R value as
fiberglass. I would need to double or triple up on them to get the same R

Has anyone seen a product that sounds like it would work well here or am I
stuck using 16" wide rolls and stapling in strips to the underside of the
subfloor instead of the joists. This is not ideal because it would compress
the edges of the insulation.

Do you think installing paper faced insulation with the paper up so I can
staple through it is a good solution?

Fortunately, I am in northern CA and the climate is mild.

Is the ROI there to warrant the expense ?

One possibility. Put nails in the beams every two feet, leaving enough
space between the heads and beams to wrap a loop of steel wire. Run two 23
wide insulation rolls between the beams and use the wire to hold in place,
i.e. the insulation is resting on wires. Kind of a PITA to do this way, but
might work.


"PipeDown" wrote in message
ink.net...
I want to insulate the bottom of the floor (inside crawlspace). The
problem is the floor joists are nowhere near 16" on center. My single
story 1000SF house is built on a deck like subfloor. It is made up of 4x8
beams running the length of the house set 4 feet apart with 2x8 tongue and
grooved planks set perpendicular. The result is a thick solid floor with
few beams underneith.

To put it another way, the floor joists are 4 feet apart and the
crawlspace access is a 2'x2" hole in the closet floor.

I was considering 4x8 sheets of solid core insulating panels cut in half
the long way but this would be expensive and would not have as good R
value as fiberglass. I would need to double or triple up on them to get
the same R

Has anyone seen a product that sounds like it would work well here or am I
stuck using 16" wide rolls and stapling in strips to the underside of the
subfloor instead of the joists. This is not ideal because it would
compress the edges of the insulation.

Do you think installing paper faced insulation with the paper up so I can
staple through it is a good solution?

Fortunately, I am in northern CA and the climate is mild.

PipeDown wrote:
I want to insulate the bottom of the floor (inside crawlspace). The problem
is the floor joists are nowhere near 16" on center. My single story 1000SF
house is built on a deck like subfloor. It is made up of 4x8 beams running
the length of the house set 4 feet apart with 2x8 tongue and grooved planks
set perpendicular. The result is a thick solid floor with few beams
underneith.

To put it another way, the floor joists are 4 feet apart and the crawlspace
access is a 2'x2" hole in the closet floor.

I was considering 4x8 sheets of solid core insulating panels cut in half the
long way but this would be expensive and would not have as good R value as
fiberglass. I would need to double or triple up on them to get the same R

Has anyone seen a product that sounds like it would work well here or am I
stuck using 16" wide rolls and stapling in strips to the underside of the
subfloor instead of the joists. This is not ideal because it would compress
the edges of the insulation.

Do you think installing paper faced insulation with the paper up so I can
staple through it is a good solution?

Fortunately, I am in northern CA and the climate is mild.

The rigid insulation is the way to go - if you've determined that the
potential energy savings and increase in comfort is worth the expense
and effort. Since your climate is mild, 2" rigid insulation should be
fine. Go with polyisocyanurate insulation (~R14 for 2") if you feel
it's worth the money, extruded polystyrene (~R8 for 2") if not.

Since your floor is so thick you can just screw the boards in place
with some of those pancake plates that they use for EIFS and use some
expanding foam to fill in the gaps.

As an alternative, and not necessarily a great one, you could suspend
2x3s on 16" centers between the existing joists, then staple up
fiberglass batts or use those wire press fit hangers.

R

On Tue, 29 Nov 2005 01:12:25 GMT, "PipeDown"
wrote:


Has anyone seen a product that sounds like it would work well here or am I
stuck using 16" wide rolls and stapling in strips to the underside of the
subfloor instead of the joists. This is not ideal because it would compress
the edges of the insulation.

Do you think installing paper faced insulation with the paper up so I can
staple through it is a good solution?

This would compress tthe middle of the insulation. I don't know
how bad that would be, but as bad as t he edges.

48 is 3 times 16. I would think you could tie the stuff up with
strings wrapped around occasional nails or something, and after all
three bats of insulation are up, nail a wood strip to hold things in
place. Or soemthing like that.

Remove NOPSAM to email me. Please let
me know if you have posted also.

PipeDown wrote:
I want to insulate the bottom of the floor (inside crawlspace). The problem
is the floor joists are nowhere near 16" on center. My single story 1000SF
house is built on a deck like subfloor. It is made up of 4x8 beams running
the length of the house set 4 feet apart with 2x8 tongue and grooved planks
set perpendicular. The result is a thick solid floor with few beams
underneith.

To put it another way, the floor joists are 4 feet apart and the crawlspace
access is a 2'x2" hole in the closet floor.

I was considering 4x8 sheets of solid core insulating panels cut in half the
long way but this would be expensive and would not have as good R value as
fiberglass. I would need to double or triple up on them to get the same R

Has anyone seen a product that sounds like it would work well here or am I
stuck using 16" wide rolls and stapling in strips to the underside of the
subfloor instead of the joists. This is not ideal because it would compress
the edges of the insulation.

Do you think installing paper faced insulation with the paper up so I can
staple through it is a good solution?

Fortunately, I am in northern CA and the climate is mild.



That type of construction is a standard type
called post and beam. I would consider insulating
the walls of the crawl space rather than the floor.

The paper should be toward the warm side, i.e. for
the floor it would be directly against the
subfloor. I would use 24" wide fiberglass so two
widths would fit between the beams and just staple
it to the floor. You might need to compress the
sides a bit that is ok. It will be a messy job,
but with the paper facing against the floor it
should go up fairly well.

However, you will still need some type of material
to support the fiberglass as it would eventually
pull away from the paper. A very wide mesh or
netting with holes at least 1" square and better
2" square could be used. Nylon might be preferred
but most anything will do. Check what is
available and cheapest in your area. Don't forget
to cover the dirt floor of the crawlspace with 4-6
mil plastic if not already covered.

On 28-Nov-2005, "RicodJour" wrote:

Go with polyisocyanurate insulation (~R14 for 2") if you feel
it's worth the money, extruded polystyrene (~R8 for 2") if not.

Since there is no constraint on thickness, you could use expanded
polystyrene foam (beadboard) that's thicker. Why pay for a high-
priced insulation that's volume efficient when you can just go with
thicker and cheaper insulation?

Mike

On Tue, 29 Nov 2005 01:12:25 GMT, "PipeDown"
wrote:

I want to insulate the bottom of the floor (inside crawlspace). The problem
is the floor joists are nowhere near 16" on center. My single story 1000SF
house is built on a deck like subfloor. It is made up of 4x8 beams running
the length of the house set 4 feet apart with 2x8 tongue and grooved planks
set perpendicular. The result is a thick solid floor with few beams
underneith.

Either staple chickenwire to the bottom of the beams, and stuff
insulation on top of that, or buy canisters of spray-on-foam and
squirt insulation in place.

wrote in message
oups.com...
Is the ROI there to warrant the expense ?


This definately is a concern too. This is my second winter in the house so
I will be able to more accurately estimate my energy needs from my gas bills
now.

"Michael Daly" wrote in message
...

On 28-Nov-2005, "RicodJour" wrote:

Go with polyisocyanurate insulation (~R14 for 2") if you feel
it's worth the money, extruded polystyrene (~R8 for 2") if not.

Since there is no constraint on thickness, you could use expanded
polystyrene foam (beadboard) that's thicker. Why pay for a high-
priced insulation that's volume efficient when you can just go with
thicker and cheaper insulation?

Mike

Thanks everyone. It looks like solid core is the most practical solution
from an installation standpoint. I just need to study the price a little
more to see if it is really worthwhile (and find just the right material
locally). I may insulate under one bedroom at first to see if it makes any
difference. I might be able to get a good price from a packing materials
company for foam core like material.

Another Idea that came to me was to string up nylon mesh (or similar) and
fill it with packing popcorn as I get it leftover from shipments at work.
Filling may be gradual but might cost nothing.

PipeDown wrote:

Thanks everyone. It looks like solid core is the most practical solution
from an installation standpoint. I just need to study the price a little
more to see if it is really worthwhile (and find just the right material
locally). I may insulate under one bedroom at first to see if it makes any
difference. I might be able to get a good price from a packing materials
company for foam core like material.

Another Idea that came to me was to string up nylon mesh (or similar) and
fill it with packing popcorn as I get it leftover from shipments at work.
Filling may be gradual but might cost nothing.

Tyvek instead of mesh/wire. The rigid is an easier installation, the
peanuts are free. I wouldn't want to be the one stuffing peanuts into
something over my head while I was lying on my back.

R

"RicodJour" wrote in message
ups.com...
PipeDown wrote:

Thanks everyone. It looks like solid core is the most practical solution
from an installation standpoint. I just need to study the price a little
more to see if it is really worthwhile (and find just the right material
locally). I may insulate under one bedroom at first to see if it makes
any
difference. I might be able to get a good price from a packing materials
company for foam core like material.

Another Idea that came to me was to string up nylon mesh (or similar) and
fill it with packing popcorn as I get it leftover from shipments at work.
Filling may be gradual but might cost nothing.

Tyvek instead of mesh/wire. The rigid is an easier installation, the
peanuts are free. I wouldn't want to be the one stuffing peanuts into
something over my head while I was lying on my back.

R


I was thinking shop vac in reverse to blow it in like blown in insulation.
Just a concept but moot since I probably only can get the peanuts in modist
sized batches.