Just stuff all those woodchips right in the wall bay there Joe, no one will ever notice.

July 9, 2009 11:34 AM

Home Remodelfilter: Why would an interior wall bay be filled with woodchips and sawdust?

We're rewiring our house (removing all the K & T) and our electrician just called me to to look at what she found coming out of one of our interior walls when she cut a hole to place a new outlet

Brief background: The home was built in 1947, the wall in question s separates a bathroom in what we assume was guest/mother in law quarters and a bedroom that is within the main house. The way the foundation and framing of the house looks it doesn't appear that this was ever an exterior wall

The bay and is full to the top with clean wood shavings/chips/sawdust. We initially thought rats nest, but it's all clean wood chips, similar to what you would put in a hamster cage or maybe a little bit bigger.

The only explanation we can come up with was it was placed in there for sound deadening purposes, but it seems really strange. It's basically a giant fire hazard from what we can gather. We've not found this anywhere else in the house throughout this rewiring project and this was one of the last walls we're opening up. The other bathrooms in the house do not have this "feature".

So any ideas? Did the house somehow have rats/mice in the past and it turns out they were exceptionally small free and clean ?

posted by iamabot to Home & Garden (9 answers total)

Best answer: Home renovations are an endless series of "WTF were they thinking?" moments. Your guess is probably right - it kills sounds and is a massive fire hazard. And right again, if it was mice there woulld be no doubt - it would be full of mouse/rat poop pellets and the chips would have broken down when soaked with urine. Also, there would probably be leaves. We had some squirrels nest in our attic and there were always leaves mixed in with the insulation where they nested. And it was urine-soaked (dried, but obviously it had gotten wet at one point).
posted by GuyZero at 11:47 AM on July 9, 2009

I think sawdust insulation was (and is?) fairly common. I've run into it several times, usually in attics. My parent's old house was insulated with a mix of sawdust and vermiculite. It was pretty messy when the walls were opened up.
posted by gyusan at 11:50 AM on July 9, 2009

Response by poster: I think the insulation thing is probably the best idea we have going right now, but it's really odd that this is the only wall in the house with it. I think it confirms the idea that the very strange layout of the house was intentional and that the front room and bathroom was indeed designed as a separate unit. Of course now I'm having to shop vac out the walls to get all of it out of there!

I'm still open to more ideas if anyone has them, I should take a picture of it, it's surreal.
posted by iamabot at 11:56 AM on July 9, 2009

When you're building a house, you get a lot of woodchips and sawdust and it's easier to sweep them up and dump them into a wall cavity than to carry them out to the dumpster. You'd be surprised at what you find.
posted by electroboy at 11:57 AM on July 9, 2009

It would be difficult to dump into a wall cavity, I think. You would need a portal near the top of the wall.

I have insulated, in the conventional way, between a bedroom and a bathroom when renovating. This is because the person in the bedroom does not want to hear plumbing sounds in the night, and the person in the bathroom wants to be able to let loose without rattling the walls.
posted by Midnight Skulker at 12:21 PM on July 9, 2009

Take a picture, you'll want it to go with the stories you will tell about your renovation exploits later on.
posted by sarajane at 12:25 PM on July 9, 2009

is it a 2-story house? they may have added the 2nd story & used that particular wall for all the particulate.
posted by msconduct at 1:10 PM on July 9, 2009

Response by poster: Single story, 3 bedroom, 2 bathroom house.

We're clearing out bays where electrical will run and then when we remodel the bathroom in 3 months we'll take the walls down and make sure it's all gone or replace it with more conventional fire resistant insulation.
posted by iamabot at 1:42 PM on July 9, 2009

Best answer: This was common for insulation. If there is roof above the wall, or if the house was balloon framed, the sawdust may have been poured in the attic for insulation and then ran down into the wall. It's not really much of a fire hazard as when it's all sealed up there isn't any source of ignition but vacuuming it up won't hurt.
posted by Mitheral at 1:47 PM on July 9, 2009