Typical house construction - little clay bricks

[Jaime]

I read the following in an ad in the HHAD property section:

"The houses are built with traditional small red bricks, made in
Thailand. This style of brick has been used in Thailand for years, they keep the house cool and insulated."

For anyone who is interested (I suggest the writer of the ad should be) this goes against everything I know about the use of 'passive cooling' (using the structure to help with the cooling of the internal environment) in buildings.

If the bricks are the small, hollow, lightweight bricks used as single skin infill between the concrete framed structure then they are actually very poor at keeping the house cool, as the construction has little thermal mass with which to absorb heat during the day, which is then released into the comparatively cooler evening air. The only real thermal mass provided is by the sand & cement render holding the blocks together (don't kid yourself that the mortar joints will do the job by themselves) and this is not really adequate at between one and two inches thick. Instead, the hollow cores of these bricks contain warm, trapped air that does indeed act as an insulant but unfortunately one that keeps the house hot!

Houses built with this type of construction - almost all modern houses in Hua Hin - are hot during the day and night and cannot be described as utilising a construction method that contributes to passive cooling of the building through thermal mass. For adequate thermal mass in the external wall construction you would need much thicker solid walls of dense brick, concrete, stone or mud such as are found in vernacular buildings throughout Southern Europe and North Africa. Walk into one of those in the heat of the day and you will realise the true effect of passive cooling.

[Jaime]

For some reason I can't edit my original post so I will add here that the point of my OP was to state that I think that the ad is misleading to potential purchasers if the bricks being referred to in it are indeed those I described above.

[Lev]

For some reason I can't edit my original post so I will add here that the point of my OP was to state that I think that the ad is misleading to potential purchasers if the bricks being referred to in it are indeed those I described above.

PM me which house it was and we'll have a word with the owners, we don't write the descriptions, they do.

[HansMartin]

Are one or rows of red bricks used? If two what is the gap between the inner and outer walls? What is the total wall thickness?

When I was in HH last, I saw a few homes being built with fairly narrow grey cement blocks. How common is that?

[johnnyk]

Are one or rows of red bricks used? If two what is the gap between the inner and outer walls? What is the total wall thickness?

When I was in HH last, I saw a few homes being built with fairly narrow grey cement blocks. How common is that?

I'm no expert but I saw the narrow grey blocks also. Interesting that they were being used on 5 million baht houses as well as ones costing half that price!

[lockwood74]

Have a look at this:



you will see the more modern method, double thickness concrete blocks, these will also hide any vertical concrete columns as they are much thicker than the traditional thin red bricks,

Regards John

[Jaime]

Are one or rows of red bricks used? If two what is the gap between the inner and outer walls? What is the total wall thickness?

Most external infill walls that I have seen are about 100mm thick overall. This includes sand & cement render both sides of the little red bricks.

The concrete blocks illustrated in the link by John demonstrate that building practices are becoming more 'engineered.' However, although an improvement on the little clay blocks I doubt they would actually keep the house cool by themselves since they are hollow and have therefore lost much of the mass that would be used to store a reservoir of heat. Houses in Thailand also tend to have large and numerous windows - another factor in daytime overheating. The mediterranean models I mentioned in my OP would have very few, small shuttered windows and masonry walls at least a foot thick in order to provide a more comfortable indoor temperature without resorting to air-con.

[HansMartin]

The concrete blocks shown in Lockwood's pictures are close to what we use in the US, but I haven't seen these in Thailand. In the US they are 4-inches thick. How thick are the ones in the picture?

There is a lot of science to passive solar relative to architecture and engineering as practiced in the US, especially in the Western desert areas. None of this has made it across the Paciifc to Thailand. It would be interesting to design and build a passive solar/"green" house. It really wouldn't cost that much more.

One of the first things I would do would be to put an exhaust fan in the bathroom. What do the Thai have against that? I really find
them in homes or hotels. Nothing like steping our of a shower into a humid bathroom and trying to dry off, and then stepping outside where it as least as humid!!!

[Jacka]

I read what Jamie wrote back in Feb. 06 about construction material widly used here in Thailand, namely "red bricks", although the article was a bit old but I just read it and would like to share what I know about construction.
The concrete blocks use in the U.S. are 8" deep (by 8" high and 16" long), they are also hollow cores which serve two main purposes one is to keep the weight down and secondly, if use on the exterior wall, every fifth or sixth cells (or the cores) will normally be reinforced with rod and fill with concrete. The reason for reinforcing the cells is to make the exterior walls act as load bearing walls and thus save the massive cost of concrete framing.
Back to what Jamie wrote about thermal protection, this can be achieved by filling those un-reinfoced, un-concreted cells with expandable foam (same material as the foam cup made from).
This type of building is much lighter than the conventional concrete frame with infill red bricks and when the dead weight (weight of the construction material) is reduced, the foundation can be reduced which translate into cost reduction.
So much for technical stuff, my point is I totally disagree with the way houses are built here in Thailand.

[Jaime]

One of the first things I would do would be to put an exhaust fan in the bathroom. What do the Thai have against that?

They could also be powered or at least boosted by solar cells, making them very cheap to run.

The reason for reinforcing the cells is to make the exterior walls act as load bearing walls and thus save the massive cost of concrete framing.

My guess is that with materials and labour being so cheap, relatively speaking, that concrete framing is not an expensive option. The same goes for Southern Europe, where it has been very popular for decades. The other advantage is that it enables the builder to get the roof on before the walls go up - very useful in the rainy season.

Back to what Jamie wrote about thermal protection, this can be achieved by filling those un-reinfoced, un-concreted cells with expandable foam (same material as the foam cup made from).

Here in the UK, these blocks can be bought ready filled with foam but are not that popular as we tend to build loadbearing masonry in two 'skins' that are tied together, with a cavity in between, which is where the insulation goes. It is a fairly labour intensive solution but has become the norm here and is a good way of providing a protective rainscreen that keeps the inner skin dry in all weathers. I noticed that one or two of the farang owned building companies have adopted this method in Hua Hin.

[johnrxx99]

Red thai brick sound spurious to me. Local materials have nothing to do with heat, sound or any insulation, it is to do with cost of construction. I am a surveyor and have never heard of brick in itself having anything to do with it.

It is the overall form of construction that is the thing. Air movement and circulation. Traditionally the Thai use teak and open volumes of space etc. Brick is recent is it not!

[Jaime]

Red thai brick sound spurious to me. Local materials have nothing to do with heat, sound or any insulation, it is to do with cost of construction. I am a surveyor and have never heard of brick in itself having anything to do with it.

It is the overall form of construction that is the thing. Air movement and circulation. Traditionally the Thai use teak and open volumes of space etc. Brick is recent is it not!

The point of this thread was to highlight the fact that the way the Thai builders mass produce their houses does not lend itself to this strategy - despite the claims of one of the advertisers - and as you rightly state it is not even a consideration. However, use of thermal mass of bricks, blocks or concrete as one element in a passive cooling strategy is a fact - as evidenced by the buildings of the mediterranean and the middle east. I don't know if you have ever spent any time in one of these 'cool, airy, open' traditional Thai houses but writing from my own personal experience I can state that they are very uncomfortable, humid, oppressive places in which to spend a night. 100 years ago, when the houses barely had walls they might have been bearable but this is not The King and I - modern Thai people do not live like that anymore.

[STEVE G]

Jaime wrote;
100 years ago, when the houses barely had walls they might have been bearable…

Hi Jaime,
I’ve stayed at the mother in laws house in Nong Ki, which still barely has walls and its as hot as buggery!
On a serious note, what do you think of Jacka’s comments on using hollow blocks with reinforcing through the cavities to make load bearing walls, would that be a usable idea in Thailand. I’m planning on building a house in Hua Hin in the near future and I’m interested in any ideas that would provide passive cooling. I’m from the aircraft industry, so my knowledge of building and construction techniques is a little hazy!

[Burger]

oops

[percy]

i am having a house built using 9 inch blocks for the whole house they are great for keeping the house cool