This looks like the best place to get answers on a few subtle questions
that I haven't seen addressed elsewhe

I've purchased a 10'X12' pre-fab shed as a reptile room. It's a white
pine 2X4 (mostly) frame with aluminum siding and pressure treated floor
(plywood over 2X6's).

I live in south Florida, so it's far more important to keep heat out
during the summer than in during the winter. I will be puting in a
small window air conditioner. I will be shooting for somewhere around
75-80 degrees F during the summer.

I will have 3 1/2" of space I can insulate in the walls and more in the
ceiling. Is 3 1/2" fiberglass insulation (R-13) the best I can do here?
I think I gather that using thicker insulation and packing it in will
be worse rather than better, but is there a better insulation I can
use? Everything else I've looked at seems to have a lower R value for
the same thickness.

Given that the siding is aluminum, would it make any difference to put
that reflective foil between the siding and the insulation, our would
that only help with a wood surface? How about between the insulation
and the wood panneling on the inside?

The shed is on blocks rather than a slab (maybe 6-8 inches above
ground). Would I gain anything by insulating under the floor or would I
be better off letting heat from inside radiate to the ground below,
which will be cooler than the air outside? Will it just be unworkable
to have fiberglass exposed undernieth holding in moisture (entirely
aside from the issue of animals nesting in it)? Would I gain more by
putting some sort of skirt around the perrimeter to keep hot air from
blowing under the floor?

I got the shed in all white to minimize heat absorbtion. Would it
matter much if I painted the roof with reflective silver roofing paint?

Anything else I haven't thought of?

Yes, I realize I may be going overboard, but anythything that reduces
the load on the AC and gives me more time before the room becomes an
oven if the power or the AC fails during the summer is probably worth
doing.

Also, any suggestions on how I could treat the white pine frame, in
place, to keep termites and such out that would not be toxic to
reptiles? Yes, I know the second part is pretty far afield for this
group, but I thought I'd ask...

Look into foamboard the foil faced is R 7. per inch vs apx R 3.5 per
inch for fiberglass batts. I thought reptiles liked it hot.

yup

Polyisocyanurate.foam

not cheap but are to beat for R per inch

cheers
Bob

how are you insulating the roof?

can you consider an "umbrella roof" another lightweight roof over the
actual roof to keep the sun off the actual roof? with an airspace in
between?

heat gain from the sun is much more than any other factor...

Mark

..

Yes, they like it hot relative to us, but it can be 95 in the shade
here in summer which is about the upper limit. In a closed room it can
get much hotter than that and snakes have no way to cool off (they
don't sweat).

how are you insulating the roof?

Fiberglass batting unless someone else has a better idea. I now see
that Owens-Corning makes a rigid fiberglass board that is slightly
better (R-15 vs R-13 for 3 1/2") but it's way more expensive and I
don't know enough about the subject to know whether that's a significnt
difference. I think I've worked with the foam board that m Ransley
mentioned and found by experiment that it burns like a sparkler if you
get it started.

can you consider an "umbrella roof"

I thought of that, but it cost me almost $600 (counting a survey) and
took 5 trips to the building department just to get a permit to drop a
prefabricated shed in the yard. I don't even want to think about trying
to get a permit to structurally modify it myself.

heat gain from the sun is much more than any other factor...

That much I was pretty sure about...

Larry Fishel wrote:
....

I will have 3 1/2" of space I can insulate in the walls and more in
the ceiling. Is 3 1/2" fiberglass insulation (R-13) the best I can do
here?

No. Likely the best you can do without adding thickness to the walls is
to use a foamed in place foam. Call around and find a contractor. The
stuff is not all that cheap, but it should not be too expensive for your
application and it will add quite a bit over what you have planed.

You may also want to consider adding a layer of rigid foam under the
outside or inside siding if this is possible with your construction. An
added inch or even less of high R value material will make a big difference
overall. This could be in addition to the foam in the wall cavity.

--
Joseph Meehan

Dia duit

On Sat, 10 Dec 2005 06:04:30 -0000, (Chris
Lewis) wrote:

According to Larry Fishel :
how are you insulating the roof?

Fiberglass batting unless someone else has a better idea. I now see
that Owens-Corning makes a rigid fiberglass board that is slightly
better (R-15 vs R-13 for 3 1/2") but it's way more expensive and I
don't know enough about the subject to know whether that's a significnt
difference. I think I've worked with the foam board that m Ransley
mentioned and found by experiment that it burns like a sparkler if you
get it started.

rockwool batts (eg: Roxul) have about R15 for 3 1/2", and usually
don't cost any more than fiberglass. A lot easier/nicer to install
too.

But is it actually for sale anywhere?

Foam board and spray in foam go in 2 basic R values R 5- 5.5 per inch
and R 7.2 per inch, R 7 spray in is an outgassing type that needs time
to release harmfull chemicals. Actualy Foamboard even foilfaced exposed
to suns heat as in a roof deck theoreticly will cook and outgas. For
sensitive animals " people too" a Non Fordmaldehide Fiberglass is
available, usualy white and labeled. Rock wool might be better but who
knows, and im not sure on the R value being higher than fiberglass. Also
the double roof or tent is interesting. Vermiculite is non toxic, I
think, out gassing is an issue not fully apreciated like smoking but can
and does harm people every day in new construction.

According to Wes Stewart :
On Sat, 10 Dec 2005 06:04:30 -0000, (Chris
Lewis) wrote:

According to Larry Fishel :
how are you insulating the roof?

Fiberglass batting unless someone else has a better idea. I now see
that Owens-Corning makes a rigid fiberglass board that is slightly
better (R-15 vs R-13 for 3 1/2") but it's way more expensive and I
don't know enough about the subject to know whether that's a significnt
difference. I think I've worked with the foam board that m Ransley
mentioned and found by experiment that it burns like a sparkler if you
get it started.

rockwool batts (eg: Roxul) have about R15 for 3 1/2", and usually
don't cost any more than fiberglass. A lot easier/nicer to install
too.

But is it actually for sale anywhere?

Certainly. Less than 5 miles from here. But that might not do you any
good ;-)

Try the Roxul web site. They list distributors/retailers in the US too.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

I would think of it simply like a home.

I wonder if a ceiling and some sort of ventilation
in the mini attic would be the way to go. It
would provide a thermal barrier between the
roof and the living structure. Insulate the ceiling
and you would have a similar construction to a
house.