# Hardiboard, Kerobond, wire frames? Freezing?



## doublereefed (Jan 3, 2008)

I'm about to embark on building a new railroad for live steam. 36"-40" off the ground, dead level... that sort of thing. I'd like to add some embankments to a long straight stretch. I've attached a photo of a nice section of Pete Comley's line to illustrate the general idea. And an HO photo that sort of shows what I'm talking about. 



















I will have a double track mainline, 8.5" centers so that 7/8ths locomotives can pass each other. With that the basic track deck will be 3x8.5" *≈* 24" deck. I then imagine 12" on each side to model the embankment. Taking some inspiration from HO shelf type layouts, the track grade would be bordered at times by a higher embankment than grade, lower than grade, etc. 

Again borrowing from HO... I'm wondering if I can use Hardiboard for the deck, and then a wire mesh (like used for stucco scratch coat) with Kerebond mortar to form the undulating embankment. The track will always be viewed from one side. It's a loop-to-loop, one side is up against landscaping, the operator is always on the one side. 

And, I'm in Utah at 5,500 ft. elevation and we get major snow and lots of freezing. I would plan to seal the hardiboard deck and the resulting "paper mache on cardboard strip" inspired mesh/mortar structure with high grade water sealer. 

Am I nuts? Has anyone done anything like this? One section of the 600' railroad will be a 150+ wandering run (150' out... that loop... and then 150' back) that I have taken to calling "The Country Mile"... it could look pretty dang awesome with some good HO style scenery work and my existing garden backdrop. 

I won't be starting this project until next Spring, but I'm working on my plans... and ideas or experience is much appreciated. 

-Richard


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## Greg Elmassian (Jan 3, 2008)

Seems that drainage will be an issue... hardibacker and your embankments should make an effective canal to contain water.

What is your support system? Many people have used a system where there is screen under the track for drainage... you could flank that with hardibacker for the banks, but that might be overkill.

What about machine cloth for the underlayment, that could tie your embankments, and then a wire mesh (the chicken wire for stucco will be too large spaces)... then a finer screen in the center to contain the ballast and allow drainage.

Greg


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## David Leech (Dec 9, 2008)

Richard,
Ever since we first met you when you organized the wonderful series of Spring Steamups in San Francisco, we knew that you were nuts, and I'm sure the years haven't changed you!!!!!
Sounds like a wonderful way to make a Gauge 1 'model railway' and not just a track.
I look forward to hearing about it as you begin the build.
All the best,
And thank you again for the original Steamups.
Cheers,
David Leech, Delta, Canada


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## Homo Habilis (Jul 29, 2011)

Hardie board and other types of cementitious products are not intended for use on other than vertical surfaces. While they are very resistant to moisture they do not survive repeated freeze-thaw cycles and will, over time, "delaminate" and crumble. While being used as a decking off ground they will still tend to absorb moisture that can lead to freezing. As with every building technique some people will have more or less success than others. Good luck and hope it works for you.

From their *Best Practices Guide*:

The James Hardie family of siding and trim products, including James Hardie® products with ColorPlus® Technology, should be stored in their original packaging in a garage, shed, or in some other covered area protected from weather whenever possible. These products must be kept covered on a pallet off of the ground; they must never be stored in direct contact with the ground.


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## Greg Elmassian (Jan 3, 2008)

There are several versions of cementious backer boards. You can indeed find waterproof varieties, they are almost twice as expensive, but I have had mine out, laying flat, no treatment for 10 years.... so while you would not want water to be puddled on it, they will survive.

10 years here: No paint or surface treatment, no protection from rain, in fact I use a hose and pressure washer to clean the leaves off it. So please stand corrected on weather resistance. Again, you need the WATERPROOF variety, and it is smooth on both sides. Again, not the usual junk you see at the big box stores. *This picture from 2008..*









*This picture below TEN years later 2018, same hardi backer boards (moved it)*










Still looking fine in 2021, I think the board is about 15 years old...


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## Homo Habilis (Jul 29, 2011)

Greg:

I would be appreciate seeing any reports, experiences or product literature regarding the survivability of *any* cementitious boards, waterproof or not, that have been exposed to repeated freeze-thaw cycles on the ground. I'm always interested in learning something new.

Assuming that the "please stand corrected on weather resistance" was directed at my comments, I'll remain seated for now. 😉

Thanks


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## Greg Elmassian (Jan 3, 2008)

unbelievable

you know, if we are posting here to HELP the person who originally posted.

1. neither the OP nor my example is on the ground (mine is 4" off the ground, his will be more)
2. drainage, i.e. no puddles of water to freeze into the backer has been emphasized
3. clearly you have little experience with the fully waterproof variety
4. 10 years of experience with photos would be evidence enough for someone with an open mind.

So i would think what I presented is HELPFUL to the OP, and I have no interest "**** Habilis" in sparring with you again.

Greg


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## Homo Habilis (Jul 29, 2011)

Greg:

Curiously what experience have you had with multiple freeze-thaw cycles with your installation? Best I can tell San Diego rarely if ever freezes: San Diego Temperatures: Averages by Month. I don't quite believe that your environment approximates Richard's "in Utah at 5,500 ft. elevation and we get major snow and lots of freezing". Well, unless climate change is occurring more rapidly than reported.

I should revise my description of "off ground" to be actually say "horizontal and not vertical". Failure does not actually require ground contact, it just requires wetting and freezing. Even you cautioned "that drainage will be an issue". I would add that it must be dry before the freezing starts. As I'm sure you know, water expands about 9-10% when frozen and that places enormous stresses on most materials; a process known as frost weathering.

Not certain how you can say that "clearly you have little experience with the fully waterproof variety". I have been lucky to have had three careers and one of them is home construction so I do feel that I have the bona fides to offer my caution. I have had to address failed outdoor backer board installation for three houses in Tahoe, Yosemite and Angels Camp. All three of those were on elevated decks and had spacers between the decking and their backer floors. These were two high-end commercial gas grill enclosures and the third a small storage shed; all three manufacturers touted their products as "fully water or weather proof". Their failures were all similar in that the floors, though protected from direct rain and snow, wicked water from their walls and splash up from rain and snow. The longest of them lasted 5 seasons before the failure started to occur.

I'm not aware which waterproof backer board you used, but even the Hardie®Backer Board with HydroDefense's installation has cautions and restrictions regarding exterior installation in certain climate zones.

As I stated in my reply to Richard "As with every building technique some people will have more or less success than others. Good luck and hope it works for you." Nothing, as yet, has altered my opinion, experience nor caution. 

My mind is open, but not so much as my brains would fall out. And, yes I am fully aware that I'm "posting here to HELP", are you?

Mark


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## Greg Elmassian (Jan 3, 2008)

You need water to freeze.... not trapping water in his structure is most of the problem.

Next issues in freeze thaw is if you have gotten water INSIDE something, and as I have proven over TEN YEARS, this board is waterpoof and does not absorb moisture.

You are running off about being a freeze and thaw expert, you need to basic issue (WATER) to be present IN the thing you are worried about.

I know you are not aware of waterproof backer board... for some reason your lack of knowledge with this product makes you keep attacking... 

So clearly my pictures are fake and I am lying.... happy now? (by the way, you can actually download the pictures and read the EXIF data proving the date)

The display in the store had a piece of the backer board in a small aquarium....

Greg


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## Homo Habilis (Jul 29, 2011)

Greg:

I'm disappointed by your apparent lack of comprehension and inability to actually address or respond to what I have asked or stated. You also appear to be attributing statements or expertise to me that I never made. Thus, I believe that further exposition from me on this subject with you will be fruitless. 

So, just to summarize my experiences regarding any horizontally exposed cementitious backer board products:

I will *assume* that some installations *may *resist, but are *not *impervious to, the effects of repeated freeze-thaw cycles.

I *know *that some backer board installations *will not* resist the effects of repeated freeze-thaw cycles over time.

Be well.

Mark


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## Greg Elmassian (Jan 3, 2008)

Not playing any longer, logic is worthless here ... sorry....* my posts are to help the OP, not to have another pissing match with you....*


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## Exador (Jan 24, 2020)

This has been an interesting discussion! My 2¢ worth is why bother with the board at all? I would dig well below the grade, put in some gravel then some 3" plastic leach pipe, back fill to the grade with gravel or DG and lay the roadbed. Only an opinion. ..


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## doublereefed (Jan 3, 2008)

All! Apologies for asking the question, getting lots of input, and then ghosting the discussion. I got a little bit busy in-between...

David! THANK you for your kind words about NSS... it was the National SPRING Steamup when we first kicked it off back in '97. I love it that it has been through three different management individuals/groups and is still going strong. Charley Lix gave me one of the aprons from the original in 1997... I will of course be wearing that forever at the NSS.

ALSO: in the meantime had the chance to have detailed 1:1's with both Jim Hadden and Dan Pantages, both who have very successful railroads and much experience in building and maintaining. And, channeling the Hitchhikers Guide to the Galaxy, the answer is: Dibond. That's where I'm headed. It's proven and fits what I need for low maintenance, freeze thaw, structural compatibility, etc. I think I will do a 3' wide deck, 8" centers, so a foot or so on each side for detailing. 2' would be better... I don't think Dibond comes in 36" panels. And 4' will be too wide.

QUESTION for you Northerners: the frost line in Midway is 36". I will build essentially a rigid table with posts sunk into concrete in 4' holes. That will be the key, or anchor, for the first phase. Can I get away with floating post pads? How much heave happens summer to winter to a concrete pad sitting on long-compacted dirt?

Thanks again!


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## doublereefed (Jan 3, 2008)

Exador, that sounds like a great method. I'm going for a table top type setup though, on a flat lot, so won't be in ground contact.


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## fsts2k (Jan 13, 2009)

My layout (70'x25') is built using concrete deck blocks sitting flat on ground, 4x4s as posts, treated 2x6s for cross beams, and steel studs to act as the channels as the table sides. I use 3/4" PVC sheets for the table top. The PVC sheets won't rot but don't have much stability so I use quite a few 2x6 or 2x4 boards to limit sagging. One note, the PVC will absorb the sun and warp if painted a dark color, I found out the hard way. I ended up using a type of paint for Vinyl that reflected the heat. 

It has been up since 2019 through a number of freeze / thaw cycles in Southwest Wisconsin without much movement. I have been reworking parts of it this year as I have one corner that was too tight (aimed for >10' radius) but generally the height has been stable.

Some pictures here:









New Live Steam Loop


No new pictures yet but made more progress this weekend. Have 44 of the 58 posts painted and decided to put 5/16 plastic trim pieces as a facia to cover the steel channels. The top is 3/4 of the way on, just ran out of 4x8 sheets.. should have rest on the 8th. Two more hard days of work and I...




www.mylargescale.com


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## doublereefed (Jan 3, 2008)

fsts2k said:


> My layout (70'x25') is built using concrete deck blocks sitting flat on ground, 4x4s as posts, treated 2x6s for cross beams, and steel studs to act as the channels as the table sides. I use 3/4" PVC sheets for the table top. The PVC sheets won't rot but don't have much stability so I use quite a few 2x6 or 2x4 boards to limit sagging. One note, the PVC will absorb the sun and warp if painted a dark color, I found out the hard way. I ended up using a type of paint for Vinyl that reflected the heat.
> 
> It has been up since 2019 through a number of freeze / thaw cycles in Southwest Wisconsin without much movement. I have been reworking parts of it this year as I have one corner that was too tight (aimed for >10' radius) but generally the height has been stable.
> 
> ...


Good to know! Thank you!


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## Exador (Jan 24, 2020)

doublereefed said:


> Exador, that sounds like a great method. I'm going for a table top type setup though, on a flat lot, so won't be in ground contact.


so sorry, I misunderstood what you were planning. I will add that if you do use the floating pad method, put them on a 6" gravel base and they won't move. Built a shed at the cabin that way. The gravel drains so no ice to expand.


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## doublereefed (Jan 3, 2008)

Exador said:


> so sorry, I misunderstood what you were planning. I will add that if you do use the floating pad method, put them on a 6" gravel base and they won't move. Built a shed at the cabin that way. The gravel drains so no ice to expand.


Great idea. The soils looks like it drains well (not clay or such) so that should help a lot.


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## fyrekop (Sep 20, 2011)

Not sure if the method you mentioned at the start of the thread "use Hardiboard for the deck, and then a wire mesh (like used for stucco scratch coat) with Kerebond mortar to form the undulating embankment." is similar to the method I use to build mountains on my site. Basically chicken wire bent to shape then covered with a layer of burlap soaked in Type S mortar as a base, More mortar slapped on top to make the the embankments, hills etc. As you layout is elevated maybe use "expanded metal mesh as a base under the embankments so water can't collect? We have regular freezes here, nothing like Michigan, but haven't had freeze-thaw issues and everything stayed in place with 75 MPH + winds we had last week.


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## doublereefed (Jan 3, 2008)

Fyrekop- that's exactly what I'm thinking of doing with regard to the mesh/screen and then mortar to make a shell. Glad to hear it is surviving freeze thaw and extreme weather.


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