Insulation-JM Spider vs Cellulose

golfdude1111

Hello,

I want to insulate a knotty pine cottage on the lake, I want to insulate the exterior walls. The place is pretty empty insulation wise.

I am wondering if I should use cellulose or JM spider. My fear with cellulose, the place has had roof leaks, I still have one I haven't found, and am afraid the cellulose will get wet, and be useless.

My fear with JM spider is that there are gaps between the wood(in the interior and it will be all over the place, and the owner will be breathing it in. The saw some posts re cancer and fiberglass.

I had planned on using silicone to close the gaps, but still am afraid with the winds off the lake, it will get into the air.

Any help is appreciated.

operagost

I find fiberglass-related cancer claims to be dubious. Regardless, the spray-in stuff isn't going anywhere, and it'll be sealing in all the spaces so there won't be any air intrusion in the first place. Cellulose is treated with stuff that will resist mold, but if mold it your greatest concern then go with the Spider.

dleaoh

Either Spider or cellulose should give you good results, but Spider installed at a density to deliver thermal and air flow resistance performance equivalent to cellulose will likely be much more expensive. No insulation on the market today poses a real health threat. With regard to mold you may want to consider the fact that all the widely reported cases of serious mold contamination of insulation have involved fiber glass, not cellulose.

jklingel

Any (non-rigid foam) wet insulation is worthless. That Spider stuff is supposed to be good, if dense packed, as mentioned. It is still fiberglass, though, and if you ever have to dig into the wall, have fun w/ FG. I just hate the stuff.

Gary in WA

Definitely plug every hole to the inside. Spider p. is better at stopping the air in the cavities; http://docs.google.com/viewer?a=v&q=...XWVzO6aRj-hhwg

Because the fibers are so small, similar the what is left in the bag after removing batt insulation..... http://docs.google.com/viewer?a=v&q=...DXEB0qoiQyYAew

With that small a product, at the higher density, be sure to wear proper safety gear while applying.

Gary

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