Shavings as Insulation in Nova Scotia

[Pavesa]

Hi,

I'm a bit off topic of woodstoves here, but I wonder if someone could give me a bit of guidance?

I've made a few postings about buying a woodstove and its position etc..

Apart from the woodstove, another major project underway is pretty much a complete rewiring of the house. It is 130 years old and was still all running off knob and tube when we bought it. We're nearly at the stage of just the 1st floor lighting running off knob and tube, the rest replaced.

I was just talking to the electrician and he's been putting a new box in the wall for a new electricity receptacle (plug) when he cut the hole for the box, wood shavings came tumbling out of the wall. He was quick and careful, so not too much came out, but he said it looks like the wall is filled with wood shavings as insulation. I know the downstairs is insulated with pink glass fiber insulation (in places you can see some below the shingle line). OK, cellulose insulation is made of paper, which is wood, but what kind of thermal properties does wood shavings have? It is a one and a half storey house so we're probably "just" talking about the end walls here. This is the diagram and pictures of the house

http://perso.wanadoo.es/andrew.bagley/HouseDiag.htm

In fact, there is no heating at all upstairs, at the moment although I have bought some ducting to feed the forced air heat up into the attic for redirection into the rooms. With the wood stove the central heating will just be for background anyway. The old guy we bought the place from converted the dining room to his bedroom, which we assumed was because he couldn't manage the stairs anymore but maybe it was the lack of insulation..

Any views would be much appreciated! We're from the UK so this is all rather new to us!

Thanks

Andrew

 

[snowtime]

Not great insulation. If tearing the walls apart is not an option and I probably would not do it then the thing to remember is wood shavings settle. At the least you should drill some pilot holes to see the level of your insulation. The good thing is you can spray foam into the holes and fill the voids. Just remember you will need a number of properly spaced holes to fill everything up properly. You need 2 holes one above the other. Spray into the lower hole and when it comes out the upper you know your good. Perhaps the bottles of spray foam available at the hardware store will do the trick.
The caveat is if you have had a hard time heating your home then it will pay to redo all the old walls. Good luck.

 

[madrone]

Seems like a fire hazard more than insulation. Cellulose insulation is treated to prevent fire. I'd be inclined to remove it and replace it with just about anything else.

(this probably goes in either the green room, or DIY forum)

 

[Wet1]

While not ideal, wood chips do have decent insulating properties, certainly better than nothing. As stated above, I'd check to see how much has settled.

 

[Pavesa]

Hi

thanks very much for the feedback. Maybe if the foam were also fire retardant it would help neutralize some of the dangers of the shavings?

Andrew

 

[Wet1]

In a 130 y/o house, I don't think the fire retardant properties of the insulation would be my biggest concern... I'd be happy knowing there was at least SOME insulation in the walls, fire retardant or not. There's a LOT of very dry wood in that house, a little more in the form of shavings isn't going to greatly increase the risk of your house going up in flames at any moment.

 

[snowtime]

Before your shavings go up in flame the house is already lost to whatever fire might happen. I would not worry about the fire hazard. Spray foam found at hardware stores is flame resistant. Just check the bottle for its flame retardant abilities.

 

[oconnor]

I have seen lots of shavings insulation in older houses in NS as well - last house I had actually had seaweed in the walls. I wouldn't worry about removal myself. Put the effort into air sealing the penetration points you come across - that will help. Better money would be spent on a good interconnected smoke alarm system - ionization and photoelectric is my recommendation. There are some wireless units around these days that will limit the need for new holes.

 

[Pavesa]

Hi

thanks for the feedback and suggestions. As part of the rewiring, we've had new mains-powered smoke alarms installed. The electricians have been cutting a hole for another new receptacle at the other end of the house and have found shavings in the wall there too. Sounds like a good idea would be flame retardant insulation foam: huge improvement in insulation and neutralize the combustible properties of the shavings as much as possible

thanks again

Andrew

 

[madrone]

I didn't mean to alarm you. I doubt the shavings are really that dangerous, I only meant that newer materials would be superior. My house is 100 years old, and full of old newspaper and bone-dry lathe. I've been updating the electrical and insulation a little at a time. Every little improvement is progress. I'd focus on the insulating properties versus the cost and ease of installation, rather than any concerns about fire.

 

[TreePapa]

We have old "puff cotton" instulation in our house (built in '47), I s'pect it has an R value of about 2 (being generous), but since we don't wanna rip out either the inside walls (nice plaster) or the siding (12" western red cedar) the puff cotton stays. The windows are the bigger thermal issue, anyway, and since summer is more of a problem that winter, my $$ will be best spent on sunblocking shades and better curtains.

Peace,
- Sequoia

 

[Pavesa]

Hi,

I just caught up with my relocated posting.. Thanks again for all the suggestions. I'll definitely look at the fire retardant properties of the foam insulation. Total would be very much the best if it exists!

Also some comfort to know that others have weird contents to their walls as well!

Cheers

Andrew

 

[Gooserider]

The old timers used all sorts of stuff as insulation, remember they basically didn't have ANY of the modern insulation materials we take for granted today, so it was a case of do the best you can with what you have... I wouldn't worry all that much about the chips being flammable - if you have enough of a fire going that the chips are involved, you would probably be pretty much screwed regardless of what sort of insulation you had, so I would say that you wouldn't gain that much by trying to replace / fire proof the stuff just for the sake of fire resistance... If you have the reason to be going into a wall section anyway, I'd replace whatever was easy to get at, but again, probably not something to go crazy over... OTOH, as suggested, doing a really good job on air sealing would probably be helpful... If you are doing siding, I'd certainly look at adding a good layer of foam board underneath, etc...

Given where you are, it might also be worth checking to see if there are any gov't programs that would help subsidize any replacement or other energy improvements - I don't approve of such as a Libertarian, but if they are there....

Gooserider

 

[mn_jon]

log homes are nicely insulated by the wood, so it stands to reason that wood chips can trap air and should provide some insulation. I would agree that it seems like a terrible fire risk with old wiring. I would replace it with cellulose if at all possible.



Jon

 

[Gooserider]

log homes are nicely insulated by the wood, so it stands to reason that wood chips can trap air and should provide some insulation. I would agree that it seems like a terrible fire risk with old wiring. I would replace it with cellulose if at all possible.

Jon

I would say the issue is the old wiring, not the wood chips as such... I would certainly rewire (note that this does NOT require demo to remove the old wiring, it can simply be disconnected) but I don't know that doing demo to replace the wood chips w/ cellulose or any other insulation would be worth it by any standard - energy savings, safety, or dollar cost...

Gooserider