Ceramic building blocks

[AliG]

They do have a very high load bearing capacity which may have been why they were chosen as my upper floors are 200mm concrete plank.

 

The lack of expansion joints is nice, I have a 30m wall with no joints along one side of the house. Also I don't like perpends which you need with timber frame and blockwork outside it.

 

I actually checked the best practice guide and it shows windows just attached with straps and small screws. This may work for a small UPVC window but some of my Alu-clad 3G windows weigh over 150kg. In this case it does say to use wood as we have.

 

Vertically the blocks are ground flat which helps keep them in line, however, horizontally they are not, the builders showed me that some were bowed way out of flat. This didn't matter as we have plasterboard over them, but could cause some issues.

 

Most manufacturing industries tend to study things until they find the best way to make something, it is surprising that this has not happened for building and there are so many competing methods. I would love to see some studies on he different methods. No one method will be the best as not all houses are the same, but you'd think there would be more standardisation.

[scottishjohn]

like this 

https://www.archiproducts.com/en/products/leipfinger-bader/thermal-insulating-clay-block-unipor-w07-coriso_117261

this one says 0.06W/mk  vlaue

Edited March 29, 2020 by scottishjohn

[Torchia]

3 hours ago, scottishjohn said:

like this 

https://www.archiproducts.com/en/products/leipfinger-bader/thermal-insulating-clay-block-unipor-w07-coriso_117261

this one says 0.06W/mk  vlaue

I believe you took a wrong figure.

 

U value of these are 0.15

[Omnibuswoman]

Can I resurrect this thread? @AliG @Torchia any thoughts on this method?

 

one reason this has been suggested is the ease of getting the blocks into site compared to timber - we have an 75m driveway that is at points only 2.2m wide. Difficult to get anything but a small lorry up there. 
 

I'm concerned that this system has some downsides that haven’t been put forward by the SE or builder. 
 

what are your thoughts? 

 

 

[PeterW]

1 hour ago, Omnibuswoman said:

we have an 75m driveway that is at points only 2.2m wide. Difficult to get anything but a small lorry up there. 

Telehandler and offload at the road. If you have space to store materials too, you could probably hire one for a week or so and get the bulky stuff delivered together. 

[Omnibuswoman]

2 hours ago, PeterW said:

Telehandler and offload at the road. If you have space to store materials too, you could probably hire one for a week or so and get the bulky stuff delivered together. 

 

Yes we do have plenty of room on the plot to store materials, so that's a good idea. I know that the local timber yard have a minature lorry that their amazing driver was able to get up the drive with some 5m lengths of timber for us. I did think it would be sensible to order as much of our materials from there as possible if they can get it all the way into the plot.

 

The builder is currently building his own extension in wide clay block, which I think is partly why he has suggested it for us as well. I've heard such mixed things about them, so I'm very uncertain indeed. I don't like the idea of having to chase all of the cables into the walls. And I understand that the render inside and out takes a long time to dry.

[AliG]

For my house I don’t really see that there was much benefit over using standard blocks considering the extra time that they seemed to take to lay the Porotherm.

 

However, I have cavity walls. If you use this kind of single skin product you may get a much faster build.

I would ask them to compare to blockwork and price it up using both. Then if it is more expensive I’d want to know what the benefits are.

 

Porotherm sell it as air tight but this is all in the detailing and nothing re-ally inherent about the blocks. They can be as leaky or airtight as any other blockwork depending how they are installed.

 

Rendering them on the outside was no problem at all.  I would think they would want to dot and dab them on the inside. I don’t think they are great for chasing stuff into as the tend to crumble when cut.

 

[Omnibuswoman]

Thanks @AliG  As we were not planning on a brickwork construction in the first place (our first preference was timber frame) I'm not sure that there are any real benefits to this system that make it worth the downsides. The builder, Dan, proposed single skin build with render inside and out to get the airtightness we want (we are going for a passivhaus), but I am concerned about the lack of cavity in which to run services etc. 

 

The only upside might be that these might be more suitable for a winter build, but the way things are going, it will already be nearly spring by the time our foundation is down, so it becomes a moot point!

[Russell griffiths]

The problem with builders, unless you get a very up to date one, is they are living in 1980, I go on another forum just for builders and the amount of them building very badly insulated houses is unreal they think 100mm in the cavity is mind blowing and they are top of their game, 50mm under ufh and they want a Nobel  piece prize. 

Do your own research and build it how you think is best for what you want to achieve and the site, don’t be led because he used it and thought it was straightforward, he might end up with a shite house whereas I believe you probably want something better. 

[Russell griffiths]

Have you had any timberframe companies come to site to look at access and erecting. 

You might find that they are more used to tight access than you think. 

[keith65]

You could look at ICF 

[Omnibuswoman]

Thanks @Russell griffiths and @keith65. 
 

Our builder is passive house trained on the Plymouth Uni course with Peter Warm and his daughter Sally, so he does know what we’re trying to achieve. (I agree with you about the general standard being woeful.) It was just an unexpected surprise when we met with him and the SE a few weeks ago and both put forward clay blocks as an option. We had never heard of them before. I’m yet to be convinced that it’s better than a stick built timber frame.
 

We prefer the method with the least amount of carbon possible, and the least amount of concrete. 

 

I’ve been in touch with MBC to get a quote. The total for foundation plus frame was about half of our budget, which made me a bit nervous when considering all of the remaining things that would need to be covered. I’ve heard that stick builds are cheaper, although there’s a lot of uncertainty around costs with prices being so volatile and inflation rising… ?

[scottishjohn]

the thing with  blockwork is you can stop and gather more funds if you need to 

--TF once you start you must get it wind and water tight pretty quick

blockwork can stand being wet for a long time 

[Omnibuswoman]

We’re in the very fortunate position of having our whole budget available which should be enough for everything, if we are careful and keep a close eye on costs. But I have been very concerned about doing a timber frame in such a wet county, in the winter. If we weren’t relying on Dan the Builder to do all of it for us I would be looking very closely at pre-fabricated systems like MBC etc.

 

Having said that, at the rate things are going, winter will be nearly over by the time it starts going up. I’m still dallying about organizing the trench for water and telecoms ?. I’ve put it on the too difficult pile. 

[Gary in New York]

Did you stick with Dan and use the Porotherm blocks? I'm starting to build my home and using their 365mm insulated blocks. Struggling to overcome issues from being the first person in the US to build with them, and to have a monolithic wall when codes all speak about the R value of the 'envelope' and continuous insulation, which my architect thinks they don't qualify for. Looking for anyone with actual experience. Thanks.

[Lilly_Pines]

On 21/09/2022 at 22:07, Gary in New York said:

Did you stick with Dan and use the Porotherm blocks? I'm starting to build my home and using their 365mm insulated blocks. Struggling to overcome issues from being the first person in the US to build with them, and to have a monolithic wall when codes all speak about the R value of the 'envelope' and continuous insulation, which my architect thinks they don't qualify for. Looking for anyone with actual experience. Thanks.

Continuous insulation applies to wood frame walls. From a quick look I think you'd need to use the R-values for mass walls: https://up.codes/viewer/new_york/irc-2018/chapter/11/re-energy-efficiency#N1102.1.2

 

The requirement is for an R-value of 8-21 depending on your climate zone and whether they consider the wall as having insulation on the inside. Obernburg looks to be zone 6 so R=21 would meet the requirements; Porotherm T7 365mm gives me a US R-value of around 31 with a quick and dirty calculation so you should be fine by the code. With the winters over there being as cold as they are I'd consider thicker blocks as an option if you aren't already committed to 365mm, but even 365mm seems to be 50% more than the minimum requirement.

 

I'm a bit worried about whether your architect is the best choice for the project if they didn't know this (or didn't know how to look it up), and would take care to double-check everything else to make sure they didn't miss other important differences between clay block and stick frame construction.

Disclaimer: I don't have actual experience but I've read a lot of https://www.buildingscience.com/ and know how to read technical text like building codes. I've researched clay blocks as one option for my house and I'm happy to answer questions with the aforementioned caveat that I mostly know things theoretically.

[Gary in New York]

23 hours ago, Lilly_Pines said:

Porotherm T7 365mm gives me a US R-value of around 31 with a quick and dirty calculation so you should be fine by the code.

The builder repping Porotherm who is helping me has said the 365mm insulated blocks are between 21 and 22 US R value. Can you show me how you came to 31?

 

Thanks Lili

23 hours ago, Lilly_Pines said:

I'm a bit worried about whether your architect is the best choice for the project

No question, but too late now. I had my own Rescheck done and the envelope did fine, based on my input of R21 for the walls. We're way above minimums in all other areas. 

[Gary in New York]

With my French consultant and two experienced (but typical mason helpers- who never saw Porotherm) it took one day to dry set the exterior walls of the garage and will take one and a half days to cement the first course (about 113' linear feet). Because there is no cement between layers (besides the first) the first layer must be absolutely precise.

 

 

Using too wet cement that might shrink even just the thickness of a piece of paper sends the level far off

 

[scottishjohn]

14 minutes ago, Gary in New York said:

Because there is no cement between layers (besides the first) the first layer must be absolutely precise.

ao how do yhey bond to next layer and is it a viable cost comparison  to going timber frame,

as with my build I am building another house inside an old granitr building 

anbody got a link to them  in uk

Edited September 24, 2022 by scottishjohn

[Mr Punter]

@Gary in New YorkI haven't seen the mineral wool infilled Porotherm blocks over here.  How much are they per m2 in the US?  365mm is very thick without any finishes.  Also the first mortar bed looks really thick.  Is that what they specify?  I appreciate it is just adhesive from there upwards.  Do keep posting as it is interesting to see how it works.

[scottishjohn]

6 minutes ago, Mr Punter said:

@Gary in New YorkI haven't seen the mineral wool infilled Porotherm blocks over here.  How much are they per m2 in the US?  365mm is very thick without any finishes.  Also the first mortar bed looks really thick.  Is that what they specify?  I appreciate it is just adhesive from there upwards.  Do keep posting as it is interesting to see how it works.

mineral wool --why not PIR foam  surely

[Mr Punter]

2 minutes ago, scottishjohn said:

mineral wool --why not PIR foam  surely

 

Well the photos look like mineral wool.

[scottishjohn]

21 minutes ago, Mr Punter said:

 

Well the photos look like mineral wool.

"Iknow nothing -I.m from barcelona Mr faulty"

[joe90]

Or beads poured in (as long as it’s not windy eh!). All I know about them is they are glued together in the horizontal but there appears to be no “glue” in the vertical joints, yes they are staggered but not air tight so draughty???

Edited September 24, 2022 by joe90

[Lilly_Pines]

4 hours ago, Gary in New York said:

The builder repping Porotherm who is helping me has said the 365mm insulated blocks are between 21 and 22 US R value. Can you show me how you came to 31?

 

Thanks Lili

Those blocks look like Porotherm T7 MW which has a lambda value of 0.07 W/mK. Over 365mm this creates a U value of 0.19 W/m²K. The reciprocal of this is a metric R-value of 5.21. Coverting this to US units with 1 K⋅m²/W = 5.56 BTU/(h⋅°F⋅ft²) gives 29. A metric U of 0.18 gives US R value of 31. If they have a lambda of 0.08 W/mK the metric U value would be 0.22, the metric R value 4.54, and the US R value 25.