The vapor retarder on top of or between layers of insulation can trap moisture.
Sawdust insulation in attic.
Same process they use for cellulose shredded paper insulation boric acid or borax is used for mold pest fire proofing.
At the bare minimum i plan to have them put more insulation in the attic.
To improve the comfort of the home pictured above one solution is to remove the wood chip insulation and re insulate the entire attic cavity with blown in fibreglass insulation.
Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation.
In the addition pitch is very low there is no floor and insulation is not covered.
This page contains a list of research papers on the use of sawdust as an insulation material.
It takes a lot of borax to do it like so much it may be cheaper to buy cellulose.
It s pathetic and i ve been heating cooling the outside world for quite some time r20 at best and that s generous.
Before you install insulation over the sawdust check the attic for old knob and tube wiring commonly installed from the late 1800s until the late 1950s.
Knob and tube wiring is made of two individual wires that run through and are connected to porcelain insulators.
All about wood chip insulation october 27 2014 1 01 am.
Right now i have the original 60 s era blown in fire retarded sawdust that is just barely covering the joists.
I have an old house with an attic that is insulated with saw dust.
There is also the problem that there is more food left in sawdust compared to paper which is pretty much pure cellulose for bugs to eat.
1 what is the best bang for my buck ie vs r value 2 should i take out the sawdust before putting new insulation in.
Granular insulation is probably vermiculite a crystalline appearing compound that insulates at about r 2 per linear inch.
I have two questions.
Any existing batt or roll insulation in the attic should have the facing against the attic drywall floor or no facing at all.
Does the job and easy to do.
I have warm attic in old part and cold attic in addition so i have both of those setups.
Sawdust does have decent insulation properties as evidenced by it s use years ago for this very purpose i grew up in a mill town and whenever someone reno d a house one of the tasks was shoveling out the old sawdust from the wall cavities but the risks far outweigh the benefits.
Commercial extruded polystyrene sheets and fiberglass insulation are expensive especially in the quantities required in solar passive homes hence the importance of local replacement materials.
In the original house insulation fiber is covered with hardboard so you don t breathe that fiber when you are in the attic.
Sawdust can smolder or burn very easily.