Mullins Luxy Build

[Gulf]

According to this pdf for Silca 250KM, it is Calcium Silicate board.

SILCA? 250KM The established calcium silicate insulation board for fireplace and tiled stove construction

The 700 degrees centigrade rating is very close to Thermogold 12. Actually, it is a little better. I can't find the proper conversion charts to compare the compression strengths and thermal conductivities. You may could use this pdf for Thermogold 12. I would call a local distributor and ask them to compare the two.

[Mullins]

I found this product on a German website.

SILCA 250KM Color gray
- Dimensions of the panels: 1250 x 500 x 40 mm
- Building material class: non-combustible A1
- Maximum temperature: 700 ? C
- Building authority approval: No.Z-43.14-117
- Pressure resistance: 1.2 N / mm? <- Guessing this is it?
- Density (standard EN1094-4): 250 kg / m? <- Or this here?
- Porosity (EN1094-4 standard): 90%
- Thermal expansion: 0.2% at 500 ? C
- Thermal conductivity (standard EN993-15): <0.1W / mK at 200 ? C

This product is relatively cheap at E24.04 a panel (about $28-$30). Max temperature is only 700C. Is this enough?
That is on www.ofen.de and I am using google translate to translate it. Spec sheet is here in English http://www.silca-online.de/pdf/silca_20-6_en.pdf

The same company also recommend on their own website for weight-bearing uses to use a product they call SILCAPAN 845

http://www.silca-online.de/pdf/silca_12-6_en.pdf

This product appears to be able to hold three times the weight and up to 1000 celcius instead of 700 C (but I cannot find a price per panel...)

I will keep looking for a supplier, and see, but any thoughts?

mullins

[UtahBeehiver]

What is the compressive strength of the fiber board, I used Themogold 12 which has a compressive strength of 650 kPa @ 5% compression, FB's board has 500 kPa @ 10% compression. I laid the floor bricks directly on the Thermogold with no issues and I am going on 5 years. So see what the compressive rating is for the fiberboard you are looking at and it should be similar in either the ThermoGold or the FB board and you should be good without the handi board. CF board does get soft when it gets wet so you need to protect board while constructing or until it is enclosed.

[Mullins]

G'day,

Considering doing Hebel and then Fibre Board, and hardibacker board (to distribute the weight), and putting the floor on top of the hardibacker. Any thoughts?

It looks like I will have to buy the fibreboard online from Germany. I won't have a chance to see it before I buy. I think it was Libouru or SableSprings whose fibreboard compressed from the weight of the oven. I want to avoid this at all costs, and thinking hardibacker would distribute the weight (and give me a nice even base to start the oven on)....

Thanks for your thoughts/feedback...

[cobblerdave]

Hello,

I posted this on Sunday, but it obviously did not post...

I have shut my build down for the winter after having two nights with ice and frost in October (very mild since however!). I went to the builders suppliers on Saturday to investigate my under hearth insulation. They never heard of ceramic fibre board, and could only suggest autoclaved aerated concrete. The blocks would be 10cm tall and are made by a company called H+H. The builders suppliers do not have the technical specs of the product and it comes in at euro 2.50 ($2.75) for measurements of approx 4.5&quot;x20&quot;x10&quot;. I understand aerated concrete is similar or the same as Hebel? The guy told me they are insulating blocks used to build an insulated house.

The price alone makes me wonder if this is suitable, as if it was any good, I would assume everyone would be buying this product instead of the other more expensive options as outlined by Russell, Gulf et al.?

Has anybody used this product? Any feedback?

Thanks,

Eoin

Gray
Ytong or ACC is. Swedish invention. Been around since the 1930s as a building material. Very popular in SEA as a building material so it's possible you local product is an import. Nown in Australia as hebel, like I said in Europe as Ytong and in Britain as thermolite block.
Not as well known in the US.
Ive only got 50 ml of hebel as the hearth insulation but it's done my well enough over 5 years now. The ovens not sunk into the insulation layer and I seem to have a good heat retention
Regards dave

[UtahBeehiver]

David,

I remember now you experimenting and researching aerated concrete as an insulator. In my old line of work, we used it a lot as lightweight structural fill over our high pressure natural gas pipelines where wheel loading was a factor. Never did any work on the thermal end of the foamcrete though. So I am interested foamcrete projects have fared since 2012. You do stretch the boundaries of concrete with your work area over the kiln and foamcrete, etc. Nice to see some outside the box innovations. I will add foamcrete to the matrix but defer to you and the thread link a a resource.

[david s]

FB's board is Alumina based vs Calcium based. Perlite is similar to vermiculite (expanded shale) and used the same way by combining with cement. One more option is FoamGlas (tm) which is glass based (like a closed cell foam except glass). Insulated fire brick is also an option. IMHO, here is a little matrix of floor insulation. There may be others and anyone is free to chime in.

Medium...............Cost......... Thermal Properties......... Structural Properties................... Water Resistant
CaSi or AlSi....... High.......... High................................ Medium....................................... Low
V or Pcrete........ Low........... Low/Med......................... Low(Shear) Med(Compress)...... Low
Ins. Brick........... High.......... High................................ High............................................. Med
FoamGlas......... High.......... High................................ Low(Shear) Med(Compress)....... High
Sand/Bottles..... Low........... Low................................. Low/Med.......................................Depends

Sorry, set up a table but it did format correctly. So just follow the order by each medium.

Russell,
An excellent comparison in an easy to read form. There is another alternative that I use a lot which is both cheaper and less water-absorbant than verm or perlcrete and that is what I call foamcrete, I am surprised nobody else has followed my lead. See "foamcrete" under finding building materials.

click here
#1

[Mullins]

Hello,

I posted this on Sunday, but it obviously did not post...

I have shut my build down for the winter after having two nights with ice and frost in October (very mild since however!). I went to the builders suppliers on Saturday to investigate my under hearth insulation. They never heard of ceramic fibre board, and could only suggest autoclaved aerated concrete. The blocks would be 10cm tall and are made by a company called H+H. The builders suppliers do not have the technical specs of the product and it comes in at euro 2.50 ($2.75) for measurements of approx 4.5"x20"x10". I understand aerated concrete is similar or the same as Hebel? The guy told me they are insulating blocks used to build an insulated house.

The price alone makes me wonder if this is suitable, as if it was any good, I would assume everyone would be buying this product instead of the other more expensive options as outlined by Russell, Gulf et al.?

Has anybody used this product? Any feedback?

Thanks,

Eoin

[DavidApp]

Hello Mullins

I replied to this thread several days ago but it turned up in Tips and Tricks?

I made 2 blocks of Perlite/Cement to go under my entry columns. It was a 5:1 ratio and I was surprised how strong it appeared to be. The edges would crumble but it had good compressive strength.
I went with FB because I did not want to gain too much height under the floor. I did consider using both Perlite/Cement and FB in combination.

David

[Gulf]

Insblock is "mineral fiber board". And, some of the newer formulas for CalSil board is being marketed as water resistant.

[Mullins]

Thanks Russell,

The table actually reformats if I turn the ipad sideway. See attached pic for anyone interested

I am guessing the insulated firebrick is the Insblock I saw some people talking about?

Cheers

Mullins

[UtahBeehiver]

FB's board is Alumina based vs Calcium based. Perlite is similar to vermiculite (expanded shale) and used the same way by combining with cement. One more option is FoamGlas (tm) which is glass based (like a closed cell foam except glass). Insulated fire brick is also an option. IMHO, here is a little matrix of floor insulation. There may be others and anyone is free to chime in.

Medium...............Cost......... Thermal Properties......... Structural Properties................... Water Resistant
CaSi or AlSi....... High.......... High................................ Medium....................................... Low
V or Pcrete........ Low........... Low/Med......................... Low(Shear) Med(Compress)...... Low
Ins. Brick........... High.......... High................................ High............................................. Med
FoamGlas......... High.......... High................................ Low(Shear) Med(Compress)....... High
Sand/Bottles..... Low........... Low................................. Low/Med.......................................Depends
Hebel/Ytong......?.................?.................... ..................High............................ ...................Depends
Aerated Conc....Low............?.......................... ............High.................................. .............Depends - Refer to David S link http://www.fornobravo.com/community/...-foam-concrete

Sorry, set up a table but it did format correctly. So just follow the order by each medium.

[Mullins]

Hello,

As I wait for a couple of weeks to remove my supports I think my build will go into hibernation (from a building point of view). I still have to plan my next steps and phases, and can probably start on my prep...

I haven't investigated too much on the below oven insulation, so would like to investigate and plan this phase now.

As I understand the two options (or two main options) are Vermicrete or Ceramic Fibre Board? Anything else worthwhile worth considering? Is ceramic fibre board calcium silicate?

Anyone have their pros/cons on the two options? Are there other options. As I understand vermicrete is cheaper, but is not very strong and can disentegrate or chip away if not protected? And CF board is expensive. I am somewhat afraid of the CF board leaning/collapsing or being uneven after reading a few threads (long time ago, so I cannot remember)

If anyone can point me to any relevant threads or has any advise, please let me know,

Mullins

[Gulf]

Great! Just, don't get yourself in an awkward position under there with a saw. At 3 to 4 weeks the 2 x 4's should be the only thing receiving any damage by being pried or hammered. Be careful .

[Mullins]

Thanks Gulf

, I will leave them 3-4 weeks then? I did put in wedges on all supports, but I reckon some of them will still be tight to tilt once the wedges are out? I may loosen the posts by removing the wedges, but may need to cut out half the supports...

mullins