Fire resistant clear finish for wood interior

[MikeOnBike]

This has probably been covered on the forum somewhere but I failed to find it.

Both of our sheds/cabins will have a wood interior.  One will be 3/8" fir plywood and the other is probably 1/4" luan underlayment.  I want to put some kind of clear finish on them to protect the wood.  I would also like something that will help retard the wood from catching on fire.  I'm not trying to make it torch proof.  Just something better than sleeping in a tinder box.  I thought about using polyurethane but I don't know much about its flame resistance.

http://countryplans.com/smf/index.php?topic=10085.msg125347#msg125347
Third picture shows the plywood.
http://countryplans.com/smf/index.php?topic=10085.msg137420#msg137420

Any ideas, suggestions or a link to a previous discussion?

[Redoverfarm]

Mike maybe something like this.  Not real sure if you can use this in combination with anything(stain) to tone down the wood or apply after stain.  The manufacturer might be able to answer your questions though.

http://www.stagespot.com/product/ROSPNT-FLAME-WD/Rosco%20Flamex%20WD%20-%20Wood

But here is one that I think is an additive for paint &/or stain.

http://universalfireshield.com/universal-fire-shield-products/universal-paint-stain/

I had a forester from Virginia stop by the cabin and we got onto the subject of forest fires.  He advised me that there was a foam that could be applied via garden hose just before an anticipated fire would near my cabin which would retard the flame somewhat.  Said it was quite costly though.  But then again so is the cabin.  I need to make a note to self to check into it further.

[Redoverfarm]

Mike I forwarded the sites to Don_P for his opinion.  He pointed out that one contained formaldehyde which may or may not be suitable for the interior.  Maybe ask FEMA as their temporary trailers/housing was off gasing from the same.  .  I would just pick very carefully to make sure that it is suitable for the interior.