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What is the ideal spacing of floor joists for supporting the weight of a RMH?  RSS feed

 
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I am going to build my RMH this year using ernie and erica's Cabin 8" plans. Whoever built the small cabin I recently purchased (that my wife, son and I eventually will move into) laid the floor joists horizontally rather than vertically. I want to redo the floor joists so the floor supports the weight.

Do you have any advice?

I'm going to the cabin this weekend to measure for supplies I'll need next time.
 
pollinator
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Travis Halverson : I think, I understand, they layed the rafters with the wide side up facing the boards rather than the narrow side, Right ? !!!

You can place a Rafter under each misplaced 2X? To make a T shaped combined piece, If you can easily jack up your floor to allow you to install
new hangers for the new joists then that should be slightly stronger than the sum of the parts ! Drive decking screws down through the floor and the
flat joists deeply into your new lower joists !

You have not told us the distance that your Joists have to span, that will be the final determiner, I THINK !

I would put things on hold, until this weekend, and take lots of pictures, and then do a sketch-up and post them here

(here your cellphone will often deal with low light conditions better than some very expensive cameras !)

Have you been to Rocketstoves.com to get Ianto Evan's brand New 3rd Edition of his great book'' rocket mass heaters '' ?
You can download a pdf Copy(s) and have possession within less than an hour after going online, and no book to lose !

With over 100,000 Rocket Mass Heaters made World Wide most have been made following the book, and 95% of all of the First time builds (that Worked )
Were made from 'The Book' !

While Ernie and Erica Wisner's plans are as all-inclusive as humans can make them, they assume that you have done your homework and already
have 'The Book '! The book and the plans are companion pieces, with 'The Book' being a most have, most read first near Requirement !

Also the whole floor bracing thing is ( except for your circumstance ) Well coved in the Rocket Mass Heaters Book !

Hope this was timely and helps! Think like Fire, Flow like Gas, Don't be the Marshmallow ! All comments an questions are solicited and Welcome Big AL !
 
Travis Halverson
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Thanks for the timely response!

You do understand me correctly. They did install the joists wide side up. The cabin is raised off of the ground a bit so I may have enough room for adding new hangars. I will take pictures and measurements this weekend.

I have Ianto's book but it's from last year so it must be an older edition. I left that at the cabin too. Oops.

My neighbor at the cabin has worked with Sunray Kelly in the past so he may be able to help me a great deal with the cob part of the RMH.

My wife and I attended Ernie and Erica's workshop in northern Minnesota a couple years ago so we have a beginner level familiarity.
 
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Hi Travis...get us the photos and dimensions and I am sure you will get all kinds of quality advice. Perhaps even just building an independent floor system above like a maru 청마루 form...
 
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Joists DEFINITELY need to be installed narrow side up. They are so much stronger this way.

The amount of weight they can carry depends on a number of things:

1. The length of the span
2. The size of the joist
3. The joist material - I beam? Common Pine? Spruce?
4. The amount of flex that is acceptable in the floor

You can play with a joist span calculator here:

http://www.awc.org/calculators/span/calc/timbercalcstyle.asp

Am I right in that there is only a small crawl space between the floor and the ground? You will probably want to add a footing between your floor and the ground underneath the RMH.
 
Jay C. White Cloud
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Hi Karen,

I do not mean to counter your post...apologies.....yet we must really be careful with "DEFINITELY."

There are countless mitigating conditions from the wood being "green wood" (i.e. wet wood) to the building modalities. The maru system I mention does not lay the timber frame joists on edge but on the flat (in many cases the joist are square) as that is part of the design...so...that would be the opposite of your post advice.

The amount of flex too is a point of discussion if one cares to, as this is technically called "deflection" and has standards of 1/360 and 1/240...anything outside those parameters typically is considered...atypical and/or historical architecture.

Regards,

j
 
allen lumley
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Jay : I too was worried about the amount of deflection and its eventual effect on the cob, though I guess that if the cob dries with the floor flexed there should not
be any Counter force to cause the cob to crack(?)

Were you thinking of laying additional Joists on top then more flooring and securing them as one whole structure ? Go slow, remember it's hard to teach an old dog
new tricks ! For the good of the Craft ! Big AL !
 
Travis Halverson
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Thanks Jay C. and Karen. Maybe the builder did intend to mimmick that other method. The floor has supported the weight of a old, heavy, cast iron wood oven and range. So that is evidence that it is fairly strong. I don't know how much that oven weighs but it's right where I want the RMH to be so I'll find out when I try to move it out of the cabin.

I'll post pics and dimensions on Sunday.
 
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Jay C. White Cloud wrote:The maru system I mention does not lay the timber frame joists on edge but on the flat (in many cases the joist are square) as that is part of the design...so...that would be the opposite of your post advice.



The bend of a joist (assuming uniform load) is given by:

Deflection = 5/384 * Weight * Length^4 / (Elasticity * Moment of Inertia)
Moment of inertia = width * height^3 / 12

So a timber, say 2x6 laid flat deflects 9 times more than a 2x6 vertically for the same load.

(2 * 6^3)/12 : (6 *2^3)/12 = 36 : 4 = 9 : 1

Please, either do these calculations for yourself, or get an engineer to do them for you. And please know whether uniform or point loads applies more to your situation.

Thank You Kindly,
Topher
 
Travis Halverson
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So a flat joist works but a vertical joist works way better?
 
Topher Belknap
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allen lumley wrote: I guess that if the cob dries with the floor flexed there should not be any Counter force to cause the cob to crack(?)



Any live load (like people walking on the floor) is also going to cause (additional) deflection, and thus possible cracking. Point loads also make a difference as the deflect the beam differently than a uniform weight.

Thank You Kindly,
Topher
 
Topher Belknap
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Travis Halverson wrote:So a flat joist works but a vertical joist works way better?



A flat joist will deflect a certain amount for a given load, a vertical joist will deflect a smaller amount. Whether they both 'work' depends on what the rest of the engineering problem looks like (i.e. how close to the tolerances is it). There are certainly points where one will work and the other will fail.

Take a long 2 x 6 and place it flat side up between two supports. Get up on it and move around. Do the same with it on edge. You will now have a visceral understanding of this issue.

Thank You Kindly,
Topher
 
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Travis Halverson wrote:So a flat joist works but a vertical joist works way better?



A vertical joist deflects less over it's span, BUT... the sheathing or flooring may deflect more between the joists.

If you simply flip the joists on edge without adjust their spacing or the flooring above, it may be weaker. Probably not, but it is possible.

Just like permaculture design, you need to look at the WHOLE of the system and not engineer a component in a vacuum to get the best results.

 
Jay C. White Cloud
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Hi Travis, et al,

As you can see...this topic...has many sides to it.

I would stress...being a public venue...that Topher's advice is very good on the general effect of sizing any "structural member." If you can not do the calculations yourself (there are several to consider) seek qualified advice or follow "proven formats."

"Deflection" that you find in most Code statutes are as much based on "comfort" and statistical averages as they are "good practice." Even many of the applied "engineering" requires taking "codified" statistics of mean averages for a given species of wood, its condition/grade, as well as, in moments of rupture, elasticity, compression...etc.etc. and then further delves into "other possible issues. Often we are (in my line of work) going so far off the beaten path of "normal" that we have to create our own modeling and/or empirical testing for the PE on our team...(great fun most of the time) and this reveals many wondrous understanding further into "green wood" and "historical wood" as well as, what can work, what was thought wouldn't work...BUT DOES...and many other infinitely interesting and enlightening actualities.

Regards,

j

P.S. Scotts observation is very much another important part...and extremely true...many "old" or "vintage" floors have joist laid flat (like "Summer beam") just because of the "whole system" or "entirety factor."
 
allen lumley
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Many years ago when I considered myself a gourmand, a fine judge of Malt and Hops two maiden ladies decided to built their own bar and open it to the public !

The framing was post and beam, the walls were 1 3/4 think tongue in groove pine plank laid up as paneling , No wall studs, and the entire roof was done with
2 X 6s on their sides, horizontal-ish not vertical-ish.

Against all odds (Location, Location,Location) this became a Construction Workers Bar and much was made of exactly what type of ladies would build a building All
Tongue in Groove and NO STUDS, and bets were made on when the roof would fall-in The building still stands 30 years later ! Big AL
 
Jay C. White Cloud
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Dear Allen,

Grand Story!!!

That is a perfect example and you took thoughts from my mind...The style they imulated is referent to by several heritage vernaculars: "Plank Frame," "Slab Frame," "Pièce sur pièce verticale" (in the French form) or relatively common here in New England "Post and Plank Timber Frame" which all of these styles are either pure Timber Frame, log and timber, or an amalgamation there of...

Many have a "horizontal" beam and floor joist system with planking...Now inlay the planking with locking joint's and you have a Korean "maru" system...

Great Story Allen....


Regards,

j
 
allen lumley
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How to Fill a Bathtub :

O.K. Now that I have your attention, this is really about how to apply caulk to seal a bathtub base to the Bathtub/shower surround !

First you fill the bathtub, then you climb in! Depending on your own and other peoples sensibilities depends on whether you you undress
First !!! In any case I still recommend warm water ! It reduces personal shrinkage !

The crack between the tub base will now be at its largest, and the floor and floor joists are deflected, any future live loading will be a small
fraction of the whole load .

Making sure the gap is clean and there are no lose particles you apply and smooth out the caulk, let cure 24 hours and drain the tub. From
now on the caulk itself is going to be under compression almost all off the time and when the tub is again filled it will return to its normal
shape and coverage !

Congratulations, this is another side of the same coin we were just looking at, and you now know how to FillCaulk a tub BIG AL !

This topic is officially hijacked and OFF- TOPIC A.L.
 
Travis Halverson
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So I don't have to stay in the tub with the water until the caulk dries? What a relief!

Thanks everyone for all the information so far.
 
R Scott
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allen lumley wrote:Many years ago when I considered myself a gourmand, a fine judge of Malt and Hops two maiden ladies decided to built their own bar and open it to the public !

The framing was post and beam, the walls were 1 3/4 think tongue in groove pine plank laid up as paneling , No wall studs, and the entire roof was done with
2 X 6s on their sides, horizontal-ish not vertical-ish.

Against all odds (Location, Location,Location) this became a Construction Workers Bar and much was made of exactly what type of ladies would build a building All
Tongue in Groove and NO STUDS, and bets were made on when the roof would fall-in The building still stands 30 years later ! Big AL



AND No one went though the wall in a bar fight!!!
 
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allen lumley wrote:How to Fill a Bathtub :

O.K. Now that I have your attention, this is really about how to apply caulk to seal a bathtub base to the Bathtub/shower surround !

First you fill the bathtub, then you climb in! Depending on your own and other peoples sensibilities depends on whether you you undress
First !!! In any case I still recommend warm water ! It reduces personal shrinkage !

The crack between the tub base will now be at its largest, and the floor and floor joists are deflected, any future live loading will be a small
fraction of the whole load .

Making sure the gap is clean and there are no lose particles you apply and smooth out the caulk, let cure 24 hours and drain the tub. From
now on the caulk itself is going to be under compression almost all off the time and when the tub is again filled it will return to its normal
shape and coverage !

Congratulations, this is another side of the same coin we were just looking at, and you now know how to FillCaulk a tub BIG AL !

This topic is officially hijacked and OFF- TOPIC A.L.


Don't you get awful pruney in 24 hours?
 
allen lumley
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Bob : In our family we called it Wee-bie,like We be pruney ! Some times there is room to build a 3/4plywood deak or bridge across the top to use for a platform to
work off of !

Caution, A large percentage of House-building contractors have personal stories about, The dry waller who stood in the tub to do the mudding and finish coats,prior
to sanding and painting, and Something was on the bottom of his/her work boot, There are tub refinishers who can come in and make an enameled tub L@@K
like new, a Fiberglass one is ruined ! Big AL
 
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no they patch fiberglass tubs too. 150 bucks to patch where a door corner went threw one. seen a painter do that in new home about 10yrs ago.

i would still shur up the floor under the heater from the ground up to joists, no matter how you went about it.
 
allen lumley
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ronald bush : I can only speak for my experience, I have seen repairs on enamel tubs last long enough for the owner to think it was his fault that an area on the tub
went bad, and not blame the builder ! I personally have never seen a patch on a fiberglass tub that was not obvious, but then $150 u.s. should buy a damn good patch!

Think like Fire, Flow like Gas, Don't be the Marshmallow ! Your questions, comments are solicited and welcome ! Big Al
 
Travis Halverson
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Sorry about the giant images.








Joists laid flat side up.


Looks like they did reinforce the floor under the stove.


The stove. Anyone in western Wisconsin who wants this stove let me know.


Are these posts done right?
 
allen lumley
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Travis Halverson : If you are serious about giving that stove away make a separate post in the wood stoves section, that is if it is not already gone ! Also in that
picture is the sheet of material that should act as a flamestop behind the Stove, It L@@Ks like Asbestos, which I have no problem with if it is in good condition!
There should be a series of squares as spacers or stand offs between your wall boat and whatever type of Firestop board that you are using. A 1'' gap will reduce
the mandatory space between the RMHs barrel and the wall from 12'' to 6'' ( I THINK !) Refer to your sketch of the post layout it is a good example of the spacing
between the sheets for good air circulation !

The posts, I am a little concerned about the single post that had flashing around it (for protection against termites?) Do you have an historical problem in your area?
the cement appears to be a surface pour to make a collar around the Post rather than a sub-surface pour to give the base of the post something to bear against ?!!

Also we can not tell if there was gravel or washed crushed stone in the bottom of the hole,for drainage ! I expect that 1 or 2 comments will be made about the use
of Pressure treated dimentional lumber !

I could not tell what kind of material was used for flooring ! Particle board or plywood, the grade used should be stamped on the sheets, it probably means another
trip to crawl under there and take a picture of the Stamp(s) !

Got to run,will check back later ! Big AL Spell check be damned !
 
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Travis Halverson wrote:.


The stove. Anyone in western Wisconsin who wants this stove let me know.



Travis, don't give up the stove as of yet!

http://donkey32.proboards.com/thread/1216/new-range-candidate-rocket-retrofit
 
R Scott
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Nice stove. If I were you I would keep it and move it to an outdoor summer/canning kitchen.

There are several ways you could reinforce under the stove, since you have relatively easy access.

Those reinforcements they placed already--you could do similar, either adding more or making them bigger. Their problem is they transfer to only one of the beams, you need to tie the beams together so they will support that load together. I would completely fill those spaces between posts and add ledgers to the posts--in essence making them act like a proper timberframe joint.

You could add more posts under that section with extra beams so the span is cut in half. Probably the cheapest option but not fun digging post holes in a crawlspace.

Those posts do not appear to be "to code" but you can't tell if they will last or not. It depends if they went deep enough to prevent frost heaves and if they put drainage in the bottom of the hole and if they put the factory finish side in the hole or properly treated any cuts.
 
allen lumley
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Travis Halverson : The possibile presence of termites now or in the near future needs to be addressed ! I assume that your cabin does not have gutters on the eaves,
Depending on how far away your fresh/potable water is you may want to make a plan to capture and use any run-off off your roof !In the meantime look where the
eaves drip on the ground now. See how much mud and dirt are starting to pile up around the base(s) of your Post(s) and any potential washouts that are starting !

To extend the amount of time you can spend at your cabin with out frostbite to your feet you will want to close in the bottom of your cabin some time, what I am going
to suggest next will task my abilities as a word smith ! On a piece of paper draw a Nazi Swastika, then divide it into its two separate pieces, you should have a line that
descends vertically down the paper,( towards your waist), jogs towards the right side of the paper, and then descends vertically ( again towards your waist ). If the first
descending leg is 3'' long the second leg will be 1'' and the final leg will be 4'' !

Eventually you will want to make a piece of Flashing that will be bend into this shape. If the cabin is 20' wide the flashing would be at lest 8 '' wide. Proper placement of
your flashing should be underneath the cabins 'Texture 1 - 11 Siding and nailed to the sill joists of your cabin ! this should allow you to then seal up the space between
the bottom of your cabin floor and the ground!

A very common practice found in hunting camps above 40 degrees North latitude and close to a Papermaker is getting large sheets of Used papermakers drier felt ,
which is a better than fair wind break but is very porous to moisture penetration and cut-to-fit around the perimeter of the structure, then nailed up at the bottom of the
floor and draping down to the ground -and tucked up underneath it will add as much to your comfort as the amount of underfloor insulation you have now !

I have seen this Drier felt ( usually not otherwise recyclable ) Painted a dark forest green in hopes that the canvass like material would then resemble a cement slab,
also painted grey and lines free hand drawn on them to make the canvass look like laid up stone from a distance ! For all whether above freezing I prop up the drier felt
in many places with sticks to increase air circulation ! All this will create a warm zone which you want, and attract critters which you do not want ! Again the flashing and
possibly 'Chicken wire' fencing will be needed to keep the critters out !

Because of location and climate I would keep all your piping and drains as close to the warmer center of your cabin, with a waterproof insulated box around any drains
going to the exterior keeping them short and vertical until down in the ground, and even then plan on having frozen drains and the need to let grey water collect in 5 gal
pails to be carried outside to be dumped during the coldest darkest 10 weeks of winter !

I would like to hear what Jay C. White Cloud has to say about your timber framing now, I would be tempted to just add braces as they are shown in 'The Book' and a
1/2'' plywood sheets over the existing floor that will carry the weight of your rocket mass heater !!

No Flue Pipe Damper ! A flue pipe damper like the one in the stove pipe behind the old stove, should never be installed or used on a rocket mass heater RMH ! Never !

For the good of the Craft ! Think like fire, Flow like a Gas, don't be the Marshmallow! As always, your questions and comments are welcome and Solicited ! Big AL !
 
Travis Halverson
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allen lumley wrote:The posts, I am a little concerned about the single post that had flashing around it (for protection against termites?) Do you have an historical problem in your area?
the cement appears to be a surface pour to make a collar around the Post rather than a sub-surface pour to give the base of the post something to bear against ?!!



I'll ask my neighbor. He's been there eight years and also helped build the cabin.
 
Travis Halverson
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allen lumley wrote:I could not tell what kind of material was used for flooring ! Particle board or plywood, the grade used should be stamped on the sheets, it probably means another
trip to crawl under there and take a picture of the Stamp(s) !



Not sure. I can't get back there for a couple weeks.
 
Travis Halverson
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Satamax Antone wrote:Travis, don't give up the stove as of yet!



Nice job on what you did with your stove!
 
Travis Halverson
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R Scott wrote:Nice stove. If I were you I would keep it and move it to an outdoor summer/canning kitchen.

There are several ways you could reinforce under the stove, since you have relatively easy access.

Those reinforcements they placed already--you could do similar, either adding more or making them bigger. Their problem is they transfer to only one of the beams, you need to tie the beams together so they will support that load together. I would completely fill those spaces between posts and add ledgers to the posts--in essence making them act like a proper timberframe joint.

You could add more posts under that section with extra beams so the span is cut in half. Probably the cheapest option but not fun digging post holes in a crawlspace.

Those posts do not appear to be "to code" but you can't tell if they will last or not. It depends if they went deep enough to prevent frost heaves and if they put drainage in the bottom of the hole and if they put the factory finish side in the hole or properly treated any cuts.



I do plan to have an outdoor kitchen. Good idea. I wonder if I would burn more wood in that stove as a summer kitchen than I would burn in the RMH during a winter of heating?

How would you fill the space between the posts? By adding ledgers in the space between the beams? Do you fasten them with long bolts or are nails fine?

How does a improperly installed post fail? Rot from the bottom up and get so weak it no longer supports any load? Would I see signs of rot?
 
Travis Halverson
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allen lumley wrote:Travis Halverson : The possibile presence of termites now or in the near future needs to be addressed ! I assume that your cabin does not have gutters on the eaves,
Depending on how far away your fresh/potable water is you may want to make a plan to capture and use any run-off off your roof !In the meantime look where the
eaves drip on the ground now. See how much mud and dirt are starting to pile up around the base(s) of your Post(s) and any potential washouts that are starting !

To extend the amount of time you can spend at your cabin with out frostbite to your feet you will want to close in the bottom of your cabin some time, what I am going
to suggest next will task my abilities as a word smith ! On a piece of paper draw a Nazi Swastika, then divide it into its two separate pieces, you should have a line that
descends vertically down the paper,( towards your waist), jogs towards the right side of the paper, and then descends vertically ( again towards your waist ). If the first
descending leg is 3'' long the second leg will be 1'' and the final leg will be 4'' !

Eventually you will want to make a piece of Flashing that will be bend into this shape. If the cabin is 20' wide the flashing would be at lest 8 '' wide. Proper placement of
your flashing should be underneath the cabins 'Texture 1 - 11 Siding and nailed to the sill joists of your cabin ! this should allow you to then seal up the space between
the bottom of your cabin floor and the ground!

A very common practice found in hunting camps above 40 degrees North latitude and close to a Papermaker is getting large sheets of Used papermakers drier felt ,
which is a better than fair wind break but is very porous to moisture penetration and cut-to-fit around the perimeter of the structure, then nailed up at the bottom of the
floor and draping down to the ground -and tucked up underneath it will add as much to your comfort as the amount of underfloor insulation you have now !

I have seen this Drier felt ( usually not otherwise recyclable ) Painted a dark forest green in hopes that the canvass like material would then resemble a cement slab,
also painted grey and lines free hand drawn on them to make the canvass look like laid up stone from a distance ! For all whether above freezing I prop up the drier felt
in many places with sticks to increase air circulation ! All this will create a warm zone which you want, and attract critters which you do not want ! Again the flashing and
possibly 'Chicken wire' fencing will be needed to keep the critters out !

Because of location and climate I would keep all your piping and drains as close to the warmer center of your cabin, with a waterproof insulated box around any drains
going to the exterior keeping them short and vertical until down in the ground, and even then plan on having frozen drains and the need to let grey water collect in 5 gal
pails to be carried outside to be dumped during the coldest darkest 10 weeks of winter !

I would like to hear what Jay C. White Cloud has to say about your timber framing now, I would be tempted to just add braces as they are shown in 'The Book' and a
1/2'' plywood sheets over the existing floor that will carry the weight of your Rocket Mass Heater !!

No Flue Pipe Damper ! A flue pipe damper like the one in the stove pipe behind the old stove, should never be installed or used on a Rocket Mass Heater RMH ! Never !

For the good of the Craft ! Think like fire, Flow like a Gas, don't be the Marshmallow! As always, your questions and comments are welcome and Solicited ! Big AL !



There are gutters. So that helps out the posts a bit. There is no potable water source nearby so I will use some roof runoff.

I'm not understanding your description of the flashing. 20' wide cabin should have 8" flashing? Is there a picture you could point me to?

I agree, the flue pipe damper will go away.
 
allen lumley
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Travis Halverson : O.K., Try a new image and try to forget the old one ! Picture a running length of drip edge ! There is the horizontal part that nails directly down
on top of the wood at the roof overhang, (and under the roof's shingles) a well made model will have enough material to reach out and hang over your gutters,
promoting the collection of run off ! Then the drip edge is recurved or bent back on itself to protect the front of the facia or just the ends of the roof rafters !

Because the starting point for the flashing is behind the existing Texture 1-11 siding we need to extend the drip edge up and under the siding, so follow me again,
the length of the material used is unimportant, the narrow way which probably should be no smaller than 8'' gets shaped with a 3'' lip that goes under the 1-11
siding, extends out under the bottom of the siding and forms a horizontal lip before being bend downward to make the outside edge under which you will fasten
what ever you use to be warm and toasty when those Arctic winds come swirling down out of the frozen north !

Every Mason that erects chimneys that come up through a roof, even if only at the eaves has a 'brake' for making up interlocking shapes from common or painted
flashing to seal edges and divert water away, and a good roofer will install metal flashing in the valleys of the roof where two sections of roof come together ! He
custom makes up the shapes to his needs using the brake. A third place these breaks get commonly used is by siding contractors who will use the painted flashing
to match and hide corners and make custom sections of drip edge above a window top, again here they start with a vertical piece that defends to bend out over the
top of the window and then continues down to hide the joint where the window casing meets siding !

You can rent a masons flashing brake, also called a roofers brake, or siding brake at a major Home improvement store and quickly learn to use the brake, or take
careful measurements and get any of these three contractors to make you up enough for your job ! By now you have probably thought of two other ways to do the
job based on what you are seeing at your cabin !

A fellow member Jay C. White Cloud has pointed out using the 'hunt for images' feature common to most search engines as a second and parallel search engine to
get images of what you want more information on in this case you could type '' drip edge images '' and when you select an image you been have the option of
selecting the article that image was used for ! I have had good luck hunting this way even when I was leaning new things !we are all visual learners ! Hope this helps
and is timely ! For the Good of the Crafts ! Big AL !
 
R Scott
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Travis Halverson wrote:
I do plan to have an outdoor kitchen. Good idea. I wonder if I would burn more wood in that stove as a summer kitchen than I would burn in the RMH during a winter of heating?

How would you fill the space between the posts? By adding ledgers in the space between the beams? Do you fasten them with long bolts or are nails fine?

How does a improperly installed post fail? Rot from the bottom up and get so weak it no longer supports any load? Would I see signs of rot?



Maybe, it depends how much you cook or can in the summer. I have a little twig rocket stove I use when I just need a single burner. The big stove would just be for canning and baking.

I would mostly nail the fillers in, three rows of nails top center and bottom. The cleats under them on the posts would transfer most of the load.

Sometimes they will rot right at the dirtline, but usually from the bottom up. No good way to tell without removing them. There shouldn't be any rot yet with pressure treated even if they did everything wrong, we are talking a 20-30 yr lifespan vs 50-100. The fix is a lot of hard work but not too expensive if you do the work, digging them out and pouring concrete piers instead.
 
Jay C. White Cloud
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Hey Travis, et al,

Sorry, I am getting really busy with the building season and other "new projects," so I will be brief. Let me me (us) know with specific questions about stuff and I am sure you will get some help.


Break down of what I see.

Architecture style...."modern folk" also called "transient camp" style. This structure really is not meant to give a longer viable lifespan than perhaps 30 years. You could squeeze a life time out of it with good maintenance and augmentation.

The posts have "shim poured" concrete, not a good practice and does little for stability. It also traps moisture against the wood. If you can remove this and replace with rock shims, I would do so.

The "shrouds" around the posts are predominantly for rodent investigation, though the can be slightly effective against professorial species of termites as well. .

Personally, I am not that concerned with your floor system, as any type of additional "dead load" will most likely (with this type of "wood diaphragm" floor system) need additional direct support measures for it specific load zones. If the floor presents as overly "springing" and additional post by just wedging in place. Again this is not "substantial" architecture, so I would, "just make it work."

I agree on the stove...SAVE IT...great for a summer kitchen application.

If I have missed something...let me know.

Regards,

j
 
Travis Halverson
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Thanks for the input everyone!

@Jay C. White Cloud: Are you suggesting that this floor system may only need an additional post or two wedged under the location of the RMH to support its dead load?

When you say a rock shim is better than poured concrete that make sense to me. Would this be one or two larger rocks chosen to fit snuggly on each side of the post?

 
Jay C. White Cloud
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Travis H. wrote:Are you suggesting that this floor system may only need an additional post or two wedged under the location of the RMH to support its dead load?



Precisely! As always, I would love for members to have a PE look over their ideas and plans...its just a wise thing to do and an extra layer of safety. However, as much as I love my Architect and PE friends (the ones on my team and/or I work with often)...most...often irritate the living compost out of me! They are "too safe"..."too over cautions"...or simply not really understanding the full potential of a traditional or natural system.

With that said...this is a straight forward build. You have a pre-existing structure...not well designed or built...per se...and you need "targeted augmentation" to extend its viable and economic life span.

So...start you RMH...feel your way around the mass you are adding to the structure, and before things get "too heavy" install secondary "point load" posts to support this additional weight. Please be careful under the structure while doing so, as collapses area common "job site" incident.

Travis H. wrote:When you say a rock shim is better than poured concrete that make sense to me. Would this be one or two larger rocks chosen to fit snuggly on each side of the post?



As you may have come to learn about me...I really don't like OPC (ordinary portland cements)...the industry behind it...what it does to our environment...and basically the "con game" that so often supports it.

Concrete around a wood post is about as silly an application you could have if you are actually trying to build something with structural integrating in balanced with viable durability. Rock shims, or hand packed and pounded smaller stones will stiffen the post placement and allow for proper drainage.

Good luck, and keep us up to speed with your progress,

j
 
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Be sure to insulate your wood floor from the heat of the burn tunnel. If possible, leave an passage for air between the floor and the burn tunnel. The spontaneous ignition temperature of wood can be lowered by exposure to heat.
 
He loves you so much! And I'm baking the cake! I'm going to put this tiny ad in the cake:
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