Hi,
I have an old house with an attic that is insulated with saw dust. In order to increase energy efficiency i would like to re-insulate the attick.
I have two questions: 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?
Thanks
Replies
Yes
thanks, i love straight forward answers. Aside form a shovel any suggestions on how to get it all out of there? (15oo sq feet)
K:)
I have two questions: 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?
I don't see any reason to take out the sawdust. It's adding some R value, and it's not hurting anything. In addition, you have the cost and time of removing it and disposing of it.
I'd just add blown in fiberglass over the existing sawdust.
Edited 2/16/2007 11:35 am ET by woodturner9
My concern about the old sawdust is mold and fire hazard.
SHoudl i be concerned or am i just a worry wart?
I'd also opt for the removal of the sawdust for reasons other than its potential insulative value.
Shop vac.
get enough hose on a big shop vac. One guy operating the business end of hose and another at the vac end turniong it on and off and emptying the collection onto a pile for removal at completion.
It'll go a lot faster than you might think.
you might even be able to rig the vac to produce a suction via blowthrough and blow the discharge into a confinement of some sort. Sucking it straight into the vac with no filter may not be effective as it may well clog the mechanism that creates the suction... maybe not. otherwise, I'd think about arranging it like a sandblasting or airbrush operates with the blowing force causing drag thorugh the additional hose for that suction. Maybe having the shop vac nearer to the business end for this configuration would work best.
vac---->---------/tee------------------------->blow this direction--------> / >dust---------------/
When you're this good, EVERYONE wants a crack at you!
http://www.petedraganic.com/
Edited 2/16/2007 10:43 am ET by PeteDraganic
My concern about the old sawdust is mold and fire hazard.
If you are concerned about it, take it out. I suspect the risk is small, but if you are concerned, take it out.
Others have suggested some good methods to remove it. Another option would be to rent or borrow a dust collector from a woodworking shop. Much more suction and volume than a shop vac. Mine will draw 1500 cfm at 11" of static pressure, through a 6" hose - enough to suck up small tools. They are also typically set up to empty into a separate container, so the emptying problem is simplified (I discharge mine into a full size trash can).
Hire a vacumn truck,one used for liquid waste,should not take long,
all mess in truck,we used that method in an attic that had a partial fire.
the sawdust was soaking wet from the firemens hoses,but it cleaned up well.
use saw dust vacuum to remove saw dust
replace with cellulose
Leaf blower/vacuume hose to suck the sawdust up and another to blow it into a dumpster. Then blow in cellulose.
In the process of re-siding our 1880-era summer home, we removed all of the sawdust from the wall cavities. There may be a bit less sawdust in the attic but, believe me, there's still a lot of it. I would follow up on Vammy's suggestion to use something larger than a shop vac to remove it. By the way, our summer home is right on the ocean and that means a constant breeze. We needed to quit early several times that summer because of sawdust in the eyes even though everyone was using eye protection.
Chip Tam
I like Yammy's suggestion. If you opt to do it your self then get one of these and a metal trash can.
http://www.rockler.com/product.cfm?page=1515
You will want to take out every bit of sawdust insulation that is there. Replace with fiberglass and mineral wool. 2 weeks ago I tried to put out a big old house fire. The house had sawdust insulation. It was a matter of minutes before the whole house was on fire. The fire department said it was the sawdust insulation that made the fire out of control. I lost my sister-in-law in that fire. Dont want to see this kind of thing happen to anyone.
I assume he figured it out sometime in the more than 14 years since he posed his question. :-)