romario

Solid wall block choice, Ytong, Celcon, Thermalite?

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Hi All,

 

My first post here.

Thank you to everyone for great information.

 

I am building a house towards Passive house standard.

I've decided to build as a 215mm solid wall with external insulation and cladding (A bit of a European style).

 

Right now I need to make a decision on the 7N blocks.

The choice seems to be:

 

Celcon

Forrtera Thermalite

Ytong

 

At the moment I am more inclined towards Ytong as they seem to be made from more natural products and cut to higher dimensional accuracy.

However, Ytong  doesn't seem to be very popular in UK?

 

Am I missing something?

 

I will appreciate any comments.

 

 

 

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Welcome

 

Ytong are available in the UK but they are harder to source. MKM do them, and they are also available in a 600mm module size which may be beneficial to you in your situation. 

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I would go with Thermalite or Celcon as they are most widely available. Annoying to run short and be hit with a long lead time.  Are you building without a cavity?

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Thank you for your comments.

 

Peter,

You are right, first time I came across Ytong blocks was at MKM branch.

 

Russell,

I am building a 20m diameter roundouse so I will be using the mortar to get the round shape so unfortunately I can't use the thin joint system.

 

Mr Punter,

I agree that Thermalite and Celcon are most widely available and I was firstly looking at them but when I came across Ytong it looked more attractive.

However, I have no experience with Ytong and that's why I thought I will put the question here.

 

Yes, there is no cavity wall.

I've decided to go for 215mm solid wall block construction with external insulation and cladding.

The reasons behind are to have good thermal mass inside and option to add more insulation on the external side.

I've added couple photos below.

 

North Side external.jpg

South Side external.jpg

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6 minutes ago, romario said:

good thermal mass

Oh dear..... Oh dear oh dear... 

We all know what you mean but give it a few hours and I'm sure you will find out why you can't just go throwing terms like that around the place Willie nillie. 😉

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I'll just leave this here:

 

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1 hour ago, romario said:

are to have good thermal mass inside

 

56 minutes ago, Construction Channel said:

Oh dear..... Oh dear oh dear... 

You may want to hold on a couple of weeks as I have been running one of my Silly Sunday Experiment (actually 50 weeks so far) about the thermal properties of different masses, but identical volumes.  The data will show what is happening, not looking good for added mass.

I also have some house data from a new build, hardly any difference between the heated and unheated sections even though they have very different masses.

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one simple question 

If you say thermal mass does not exsist -and that having more mass inside the insulated envelope does nothing

why do you use a concrete slab"thermal mass " for your floor for UFH -

-you use it cos it stores heat and lets it out slowly 

surely that is the definition of a thermal mass if such a thing exsists?

 same as a wine cellar is under ground or a cave cos the temp stays stable due to the "mass of rock around it

 

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29 minutes ago, scottishjohn said:

one simple question 

If you say thermal mass does not exsist -and that having more mass inside the insulated envelope does nothing

why do you use a concrete slab"thermal mass " for your floor for UFH -

-you use it cos it stores heat and lets it out slowly 

surely that is the definition of a thermal mass if such a thing exsists?

 same as a wine cellar is under ground or a cave cos the temp stays stable due to the "mass of rock around it

 

You use concrete as it can store heat very well but also you get the added bonus that you can walk on it. Water is a great material for storing heat but wouldn't be the best choice for a floor. 

The problem with using the term thermal mass as has been explained countless times is you can't measure it as there is no unit in science for doing so. So while everyone knows what you mean it's just not the correct term .

 

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1 hour ago, scottishjohn said:

one simple question 

If you say thermal mass does not exsist -and that having more mass inside the insulated envelope does nothing

why do you use a concrete slab"thermal mass " for your floor for UFH -

-you use it cos it stores heat and lets it out slowly 

surely that is the definition of a thermal mass if such a thing exsists?

 same as a wine cellar is under ground or a cave cos the temp stays stable due to the "mass of rock around it

 

 

 

Heat storage isn't proportional to mass, irrespective of the material.

 

The key parameters are specific heat capacity (see here: https://en.wikipedia.org/wiki/Specific_heat_capacity) and thermal conductivity (see here: https://en.wikipedia.org/wiki/Thermal_conductivity)

 

Materials with a high mass do not necessarily store the most heat.  For example:

 

Gypsum (plaster/plasterboard) = 1,090 J/kg.K

 

Concrete = 880 J/kg.K

 

Water = 4,182 J/kg.K

 

From the above it's clear that concrete has a significantly lower specific heat than other materials, which pretty much proves that mass is not a good indicator of the ability of a material to store heat.

 

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Sure I went to a winter rave called ‘Thermal Mass’ once. 

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2 hours ago, Brickie said:

Sure I went to a winter rave called ‘Thermal Mass’ once.

They have one called 'Tropical Pressure' down here.

Would hate to think what the SI derived unit for that is, probably 'E's'.

 

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On 11/06/2019 at 21:27, JSHarris said:

I'll just leave this here:

 

Thank you for that, very interesting reading.

I suppose my knowledge on the words "Thermal Mass" was only taken from educating myself about Passive Houses.......

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On 11/06/2019 at 21:59, SteamyTea said:

 

You may want to hold on a couple of weeks as I have been running one of my Silly Sunday Experiment (actually 50 weeks so far) about the thermal properties of different masses, but identical volumes.  The data will show what is happening, not looking good for added mass.

I also have some house data from a new build, hardly any difference between the heated and unheated sections even though they have very different masses.

Thank you.

I would love to see what your set up and results are as I was planing to run some kind of experiment too.

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2 minutes ago, romario said:

I would love to see what your set up and results are as I was planing to run some kind of experiment too.

Just a couple of weeks to go.  Then I can write it up in the best undergraduate fashion i.e. late at night and quickly.

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Did you decide on Ytong blocks @romario. Jewsons are offering them to us at £11 per sq m as all others are out of stock.

 

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2 hours ago, patp said:

Did you decide on Ytong blocks @romario. Jewsons are offering them to us at £11 per sq m as all others are out of stock.

 

 

Is that ex VAT or inc VAT..? I’m being quoted £9.20 by TP and £9.25 from MKM ex VAT currently. 

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I assume they are ex VAT. That's how most merchants quote. I will check and then take a look elsewhere if we decide to go with them.

 

Just need to know if they are any good or not?

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Ytong are fine but I would shop around for quotes. How many do you need ..? A full load is 158sqm near enough, if you can take 22 pallets and stack them on site then you can get some really good prices. 

 

Where are you located ..?

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On 08/07/2019 at 13:12, patp said:

Did you decide on Ytong blocks @romario. Jewsons are offering them to us at £11 per sq m as all others are out of stock.

 

Hi,

I've decided on Ytong and got competitive price from MKM 

If you need full load you can get better price for direct delivery to the site.

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How are you going to get blocks to sit nicely in that radius. 

Would you not be better with a shorter block, brick so it follows the radius better, it will be awfully notchy otherwise and a major pain to fit your external insulation. 

 

Are you dead dead set on this method. 

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I love the house design by the way, I’m just not sure 440mm blocks will follow your 10m radius very well, have you thought of icf. 

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You have to cut each block in half to get a curve anywhere near decent. Which is very time consuming. Building a radius with blocks can't be done with a line so having to cut each block plus build free hand you will be paying a massive premium to build in that shape. 

Then as @Russell griffiths also says how are you going to bend enough insulation around that shape so you get it to passiv standards.

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