Cordwood Shop

[Gromgor]

Hi all,

 

   I'm a new smith looking to construct a good workshop. Not only for my blacksmithing, but also for storage of various things. I have a lot of long-term plans and part of that is I intend to build a cordwood home. As with smithing, trying to go large right from the start is only going to end in disappointment, so I decided to build a very simple cordwood shop, to see what things I need to work out before I begin construction of a house.

 

   What I have currently is a large steel carport. Those simple, pre-fab, throw up in a day kind. It is approximately 16' wide and 24' long. It has no sides. I intend to use cordwood construction to give it sides.

 

   My concerns are this: what is the chance of fire for such a building? Has anyone ever tried this and if so, what are your thoughts and opinions?

 

For those that might not know what cordwood construction is:

 

http://en.wikipedia.org/wiki/Cordwood_construction

 

http://cordwoodconstruction.org/

 

http://www.daycreek.com/dc/html/allthingscordwood.htm

[Daniel.85]

Google "blacksmith shop" and look at the images, lots of the old shops look like they would burn down in seconds. The cordwood method looks less flammable, fire hazards are inherent with this hobby, just practice common sense and have the proper safety equipment.

[Jim Kehler]

I think that  it would be too dense to easily catch fire, but this is from a blacksmith with a straw bale smithy :)

[ken leedy]

My second shop was built of straw bales. I loved it.

[Bentiron1946]

I don't know that I'd so much afeared of fire on the inside as rot on the outside. Looks like the end grain would tend to split and check over time and moisture collect in there and cause rot to take hold. Looks very pretty though.

[Gromgor]

I don't know that I'd so much afeared of fire on the inside as rot on the outside. Looks like the end grain would tend to split and check over time and moisture collect in there and cause rot to take hold. Looks very pretty though.

 

Cordwood buildings have survived thousands of years. Because of the path of the grain through the wall, with only the ends exposed, the wood, though it gets wet, does not retain the moisture so it doesn't rot.

[Glenn]

I would think lots of sealant applied on a regular basis to the outside of the wood would be in order. Check to see if the wood is placed level or on a slant to the outside to shed water.

[Drewed]

Put a coat of "plaster" on the inside and you should be just about fire proof.  How many smiths have lost anvils because their stump caught on fire?

[MILO74]

I'll be putting up a small cordwood shed this summer.  It is timberframed with treated 6x6.  (I used the plans and ideas based off  from this book:  http://www.stilesdesigns.com/sheds.html.  I am using black locust logs (very rot resistant) that have been cut and seasoned for about a year.  They also have been peeled and although have checked some should be fine.  I dont recommend that you coat the inside of the walls  (or use any sealent)* to allow the logs to breathe/rid any moisture they capture. (From what I have read when cordwood homes/structures are built and are to be insulated the outside walls are allowed to have a 1-2 inch airspace between then and the "inside" walls (like a modern brick stucture) to allow for proper ventilation.   As far as fire hazard I would be more concerned about the framing used for the roof than the walls themselves. I imagine it would take some dooing to ignite the end grain of a log encased in morter.

 

*if you want to take some extra precaution to keep wood from rotting (besides using rot resistance species such as black locust, white oak, red/white cedar, and even cherry) the wood bolts themselves could be soaked in homemade perservative such as borax and "non toxic" antifreeze.  You can find recipies for this concoction which has been found to be fairly effective aginst rot/fungal attacks by the log home folks. 

[ThomasPowers]

Can I have a cite for the "Cordwood buildings have survived thousands of years"  Or is this supposed to be the method has been in use for thousands of years?  It is a very labour intensive method before the cross cut saw or chainsaw and very wood intensive too.  

 

I don't recall seeing it used in medieval times anywhere in western europe.  Eastern Europe did use log cabins in places but my book on them doesn't mention cordwood buildings there either.

[Judson Yaggy]

I don't know about thousands, but this is a common historical building method (200 to 500 years?) in Scandinavian countries.  In Europe last I checked.  

[doc]

 Check this link out............. http://www.daycreek.com/dc/html/dc_cordwood_masonry.htm 

[Neil Blythin]

Hmm, I'm a bit skeptical about the 'thousands of years' rumour that often gets spread around when discussing cordwood construction.  I've done quite a bit of research, and most of those claims are anecdotal.  

 

Cordwood buildings certainly goes back to the mod-1800's in North America, having a few different waves of popularity in the 1890's, during the great depression, immediately post-war, and another resurgence in the 1970's.

 

The earlier buildings were often clad in something (a coat of lime mortar, or clapboards); although many were left with the log ends exposed - and seem to handle the weather just fine.  Exposed logs tend to act in much the same manner as brick; they get wet, but can breathe, and so they dry out.

 

As far as fire risk goes, I'm in the process of planning my own timber-frame and cordwood smithy (hence the research I've done on it); and am not personally worried about it.  The materials are fairly dense, and should be no more prone to burn than a stick framed building clad in plywood - which many people are using.  Again, because the end grain is exposed, the wood doesn't get that dry.  If one were *really* that concerned about it, treat the inside surface of the walls with a borax solution.  

 

As has been mentioned, not too many smiths have stories of their anvil stump bursting into flame.

 

Oh, and ThomasPowers - you are correct in it being a more labor intensive building method (cross cutting all that wood); but it utilizes cheaper materials.  There were times (i.e. during the depression), when labor was more readily available than money or materials.  One guy, building his own house, could go through an already logged area and scavenge undersized or overly crooked trees that the loggers left behind.  If you're broke, but have time on your hands....

 

Gromgor: if you haven't already read it, I suggest laying your hands on a copy of "Cordwood Building - The State of the Art" by Rob Roy (ISBN: 978-0-86571-475-5).  It's an excellent reference.  The few people I found that had actually built any cordwood buildings, all pointed me towards that book.

 

Cheers,

Neil

[lcb]

Gromgor - I have a copy of the book Complete Book of Cordwood Masonry Housebuilding by Rob Roy if you'd like to borrow it.

Larry

[Gromgor]

I appreciate the offer, but I already have enough reading material. =)

 

What I do need though is the wood and the time, heh.

[ThomasPowers]

Some of the first "environmental laws" enacted were in England because they were running out of wood which impacted keeping their Navy in Ships---so they banned any new iron smelting set up in the forest Dean.  Wood was not always a cheap material in Western Europe.  Scandinavia and Eastern Europe had much better supplies of it.

 

As to dating Dendocronology is considered one of the best methods of dating archaeological sites around, should be no issue as to when a wooden structure was built.

 

So I think that after the perfection of the cross cut saw; or even more after the powersaw, the building of cordwood structures does become a lot easier and cheaper and their use in areas with a good wood supply and bad weather where the insulation aspects would help is much more believable.  Why does it have to be an ancient method?  Why not just a modern method that works?

[Woodsydad]

How many thousands of smithys have had wooden floors and survived for a hundred or more years? My vote is to go for it.

[FredW]

I like the idea and looks of cordwood building. I had kinda kicked that idea around as well. Also thought i would use a lime mortar as well. If you wanted to get real primative you could actually heat the limestone yourself, with a furnace, and make your own lime mortar from scratch. I saw a show on history I think about Thomas Jefferson's home. They rebuilt it using the methods and material of the time. Was pretty cool watching them make the lime mortar.

 

Fred

[Neil Blythin]

... If you wanted to get real primative you could actually heat the limestone yourself, with a furnace, and make your own lime mortar from scratch...

I'm currently going to school for a program in 'Built Heritage Conservation', and we regularly use lime mortars (and lime plasters) as its the 'go-to' material in restoration/conservation work.  Once you get used to it, its far more enjoyable to use than modern mortars.  Last fall we did a lime burn at school. It was really neat to see chunks of limestone go into the kiln, pull quicklime out and mix up your own lime putty.  Its really not a complicated process, it just takes a bit of time and a lot of charcoal!

[Frosty]

The problems cordwood construction is pretty much in line with log buildings. If it sits unused it'll start to rot, we call log a "living" structure as it needs to breath or have a thermal cycle to cause it to. it's also really susceptible to insects termites and carpenter ants LOVE wood piles. We have to sprinkle ours with ant bait. A sructure, cordwood or log benefits from a little copper sulfate painted on. Cladding it afterwards is more healthy as it's not so good rubbig elbows with copper sulphate. It's not terribly toxic as lots of folk believe but it's not a GOOD thing either so cladding goes a long way.

 

Hay bales need plastering and I'm thinking a little somethig to inhibit bugs is good too. I don't know abot something like copper sulphate though.

 

 Soil filled tire structures work pretty well for smithies and you coud probably get a grant from the gvt. as a recycler. Cladding the inside is a really good idea as once tires get burning it can take a Loooong time to put it out. http://en.wikipedia.org/wiki/Tire_fire. The Royster tire fire is the one I was thinking of but gee whiz, there's quite the list isn't there.

 

Frosty The Lucky.

[FredW]

Neil, I got to try that one day. Was pretty cool watching them do it and then add the water and it instantly began to boil. Turned to a gel and said could store it that way in buckets for quite a while. Also said it has a long hardening time and will also breath. My 100 plus year home was built with lime mortar and still looks good today. There are some parts that need repointing though. Afraid to do that as i really don't know much about it and not sure any of the local brick layers do either and could be difficult matching colors etc. Needs to be done though. You can see parts where it had been patched with modern brick mortar and it looks terrible.

 

I also thought about doing a burn but using wood instead of charcoal. I would do it on a very small scale, maybe a 5 gallon bucket at a time.

 

Fred