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[Kwasaki]

Daffy D, on 2012-02-04 11:35:41, said:

Reading through this and other threads it seems that exterior cavity walls is the way to go.

The thing is how do you get air circulation in the cavity?

Do you put some air bricks along the bottom and top of the exterior wall? If so what sort?

Air bricks are used for venting a roof area above ceiling level and below raised ground floor areas, not within the cavity wall.

[klikster]

Kwasaki, on 2012-02-04 10:24:57, said:

klikster, on 2012-02-04 08:15:49, said:

Naam, on 2012-02-04 05:15:02, said:

klikster, on 2012-02-03 13:18:03, said:

^ Are we talking apples and orangutans here?

Are you denying the efftiveness of a radiant barrier?

basic solid state physics: a double wall of gas concrete blocks, closed on top to avoid air circulation, makes a radiant barrier as superfluous as are the boobs of a nun who vowed eternal celibacy.

Whether that is fact or not; my comment was in response to a comment that responded to a post about a double wall of breeze-block.

Well !! you do what you think is best you can use what ever you like to create a barrier, there's a lot of fruity hype out there and there's mutiple ways to do a build.
Some people here have a limited buget not everyone is fortunate enough to afford high quality so it's also ridiculous to call cheaper materials low quality they can be just as effective if used correctly.

I think you are quoting the wrong poster. I never said anything close to " .. call cheaper materials low quality ..".

[Daffy D]

Kwasaki, on 2012-02-04 12:52:04, said:

Daffy D, on 2012-02-04 11:35:41, said:

Reading through this and other threads it seems that exterior cavity walls is the way to go.

The thing is how do you get air circulation in the cavity?

Do you put some air bricks along the bottom and top of the exterior wall? If so what sort?

Air bricks are used for venting a roof area above ceiling level and below raised ground floor areas, not within the cavity wall.

I was thinking of the type they have on the exterior walls of houses in th UK. Can't say I've seen them over here, but probably not looking hard enough.

 imagesCAFUM1PS.jpg   7.99K   2 downloads  images.jpg   8.67K   2 downloads  images-2.jpg   4.89K   2 downloads

[Kwasaki]

klikster, on 2012-02-04 15:15:20, said:

[I think you are quoting the wrong poster. I never said anything close to " .. [i]call cheaper materials low quality[/i] ..".

I was refering to your barrier theory first part.

Second part ref materials was just a general comment not directed at you.

[Kwasaki]

Daffy D, on 2012-02-04 18:29:39, said:

Kwasaki, on 2012-02-04 12:52:04, said:

Daffy D, on 2012-02-04 11:35:41, said:

Reading through this and other threads it seems that exterior cavity walls is the way to go.

Air bricks are used for venting a roof area above ceiling level and below raised ground floor areas, not within the cavity wall.

I was thinking of the type they have on the exterior walls of houses in th UK. Can't say I've seen them over here, but probably not looking hard enough.

 imagesCAFUM1PS.jpg   7.99K   2 downloads  images.jpg   8.67K   2 downloads  images-2.jpg   4.89K   2 downloads

Maybe you have not seen them here because most floor are solid concrete.

There are different types of venting for walls using filters but still keep an insulated cavity closed.

The air-brick picture on the right is venting the underneath of internal flooring.

The picture on the left is not quite right IMO.

 air-brick sleeves.jpg   12.31K   2 downloads  

[sezze]

Kwasaki, on 2012-02-04 20:21:47, said:

Daffy D, on 2012-02-04 18:29:39, said:

Kwasaki, on 2012-02-04 12:52:04, said:

Daffy D, on 2012-02-04 11:35:41, said:

Reading through this and other threads it seems that exterior cavity walls is the way to go.

Air bricks are used for venting a roof area above ceiling level and below raised ground floor areas, not within the cavity wall.

I was thinking of the type they have on the exterior walls of houses in th UK. Can't say I've seen them over here, but probably not looking hard enough.

 imagesCAFUM1PS.jpg   7.99K   2 downloads  images.jpg   8.67K   2 downloads  images-2.jpg   4.89K   2 downloads

Maybe you have not seen them here because most floor are solid concrete.

There are different types of venting for walls using filters but still keep an insulated cavity closed.

The air-brick picture on the right is venting the underneath of internal flooring.

The picture on the left is not quite right IMO.

 air-brick sleeves.jpg   12.31K   2 downloads  

It probably is the right picture,  it is installed below the vapour barrier for venting underneath the floor like you said . The cavity between the walls is NOT vented , or you will loose it's purpose . Air is a good insulator , but only non moving air . That is the basic principle of most insulation material , trap air in bubbles or within it's cavities to create non moving air .
Also , and very important in Thailand , if you vent your cavity wall , you create the ideal playground for bugs ( anything from roaches to wasps to ants etc etc ) .

[Daffy D]

Ok! So no venting the cavity wall.

Cheers

[Kwasaki]

sezze, on 2012-02-05 07:48:16, said:

Kwasaki, on 2012-02-04 20:21:47, said:

Maybe you have not seen them here because most floor are solid concrete.

There are different types of venting for walls using filters but still keep an insulated cavity closed.

The air-brick picture on the right is venting the underneath of internal flooring.

The picture on the left is not quite right IMO.

air-brick sleeves.jpg  

It probably is the right picture,  it is installed below the vapour barrier for venting underneath the floor like you said . The cavity between the walls is NOT vented , or you will loose it's purpose . Air is a good insulator , but only non moving air . That is the basic principle of most insulation material , trap air in bubbles or within it's cavities to create non moving air .
Also , and very important in Thailand , if you vent your cavity wall , you create the ideal playground for bugs ( anything from roaches to wasps to ants etc etc ) .

No not right, left !! The left picture in " Daffy's " post   on the left is not correct IMO,  the picture in my post is correct as you have noticed below DPC, or drip tray level.
Wooden floors are vented in this way.
Insulation yes that's why bricks have frogs and block have holes.
There are venting devices similar to my post picture that have filter traps which stop Thailands bugs if you so wished.
Regards K

[Kwasaki]

Daffy D, on 2012-02-05 10:37:43, said:

Ok! So no venting the cavity wall.

Cheers

Yep !!  use brick/block ties 60mm or 100mm cavity.

Insulate your upper ceiling level, vent your roof as in flow through, bug mesh internally.

[anterian]

One thing no one has mentioned is the modern super reflective paints to use on outside walls. I used an Australian brand, available in Thailand. It claimed to reflect 80% of incident radiation, my house is definitely cooler now.

[JoePai]

anterian, on 2012-02-05 14:30:11, said:

One thing no one has mentioned is the modern super reflective paints to use on outside walls. I used an Australian brand, available in Thailand. It claimed to reflect 80% of incident radiation, my house is definitely cooler now.

Interesting - what is the name - or website address please ?

[necronx99]

JoePai, on 2012-02-06 10:24:02, said:

anterian, on 2012-02-05 14:30:11, said:

One thing no one has mentioned is the modern super reflective paints to use on outside walls. I used an Australian brand, available in Thailand. It claimed to reflect 80% of incident radiation, my house is definitely cooler now.

Interesting - what is the name - or website address please ?

This is one,

http://www.dulux.com...ld-heat-reflect
http://www.dulux.co....cts_display.jsp Thaland

[sezze]

necronx99, on 2012-02-06 12:25:33, said:

JoePai, on 2012-02-06 10:24:02, said:

anterian, on 2012-02-05 14:30:11, said:

One thing no one has mentioned is the modern super reflective paints to use on outside walls. I used an Australian brand, available in Thailand. It claimed to reflect 80% of incident radiation, my house is definitely cooler now.

Interesting - what is the name - or website address please ?

This is one,

http://www.dulux.com...ld-heat-reflect
http://www.dulux.co....cts_display.jsp Thaland

All big paint names in Thailand have similar products in their range . I'm not sure if they really help for heat , but as purpose of paint , it is good quality .

[anterian]

sezze, on 2012-02-06 19:37:41, said:

necronx99, on 2012-02-06 12:25:33, said:

JoePai, on 2012-02-06 10:24:02, said:

anterian, on 2012-02-05 14:30:11, said:

One thing no one has mentioned is the modern super reflective paints to use on outside walls. I used an Australian brand, available in Thailand. It claimed to reflect 80% of incident radiation, my house is definitely cooler now.

Interesting - what is the name - or website address please ?

This is one,

http://www.dulux.com...ld-heat-reflect
http://www.dulux.co....cts_display.jsp Thaland

All big paint names in Thailand have similar products in their range . I'm not sure if they really help for heat , but as purpose of paint , it is good quality .

i can vouch that they do make a big difference to the internal heat. Although dearer than normal 4 seasons type paint, they are much more durable. I used to paint my outside walls annually, now since I used this paint 3 years ago I have not had to repaint.

[crazykopite]

sezze, on 2012-01-29 21:39:11, said:

bankruatsteve, on 2012-01-29 21:03:54, said:

Superblock/Q-Con is the best value.

Best value on what points ?? Breeze blocks are way cheaper , and have near the same building time . Insulation value of the Q-con is the best , but doubling up the breeze blocks gives probably better value then the q-con . The prize difference is , even with doubled walls , still quite something . I do not see the value of the Q-con blocks .

breeze block you can go up 5 courses at a time super block you can keep going and going and going plus isulation is far better !!!!!

[crazykopite]

Khun Jean, on 2012-02-01 17:48:05, said:

klikster, on 2012-02-01 10:20:28, said:

Quote

Reflection and emissivity by surfaces can ONLY occur in SPACE. The ideal space is any dimension 3/4" or more. Smaller spaces are also effective, but decreasingly so. Where there is no air space, we have conduction through solids. When a reflective surface of a material is attached to a ceiling, floor or wall, that particular surface ceases to have radiant insulation value at the points in contact.

So in that case, if we simply "pack" the space between blocks with fiberglass and foil, have we essentially "foiled" our efforts.

Would it actually be better to glue foil to one wall of blocks?

edit: added second quote and comments

Fiberglass and materials like styrofoam have very good insulation properties because they conduct heat very poorly.
The ideal material would be a small layer of styrofoam with aluminum foil on the side where you want the heat kept out.

innerwall, styrofoam, aluminum foil, space 1 or more inches, outer wall.

The aluminum reflects the radiant heat and the styrofoam helps to restrict conduction of the rest. Adding another styrofoam/aluminum foil to the outer wall will reduce it even further but the extra cost will not be worthwhile.
The outer wall should be 'thin' and the innerwall should be thick.
The outer wall will radiate heat out more quickly, although in Thailand the differences in temperatures during the day is not that big (small delta T).
Having an airflow in the space between the walls would replace hotter air with cooler air lowering the temperature even a little bit more and will prevent moisture buildup that can cause mold.
The innerwall functions as a heatsink. If you use airconditioning the innerwall cools down and will help to reduce temperature fluctuations between airconditioning cycles because of its thermal mass.

A good way to keep the house cool is to ensure a good roof overhang and lots of undercover out door terrace.

[crazykopite]

crazykopite, on 2012-02-09 11:29:06, said:

Khun Jean, on 2012-02-01 17:48:05, said:

klikster, on 2012-02-01 10:20:28, said:

Quote

Reflection and emissivity by surfaces can ONLY occur in SPACE. The ideal space is any dimension 3/4" or more. Smaller spaces are also effective, but decreasingly so. Where there is no air space, we have conduction through solids. When a reflective surface of a material is attached to a ceiling, floor or wall, that particular surface ceases to have radiant insulation value at the points in contact.

So in that case, if we simply "pack" the space between blocks with fiberglass and foil, have we essentially "foiled" our efforts.

Would it actually be better to glue foil to one wall of blocks?

edit: added second quote and comments

Fiberglass and materials like styrofoam have very good insulation properties because they conduct heat very poorly.
The ideal material would be a small layer of styrofoam with aluminum foil on the side where you want the heat kept out.

innerwall, styrofoam, aluminum foil, space 1 or more inches, outer wall.

The aluminum reflects the radiant heat and the styrofoam helps to restrict conduction of the rest. Adding another styrofoam/aluminum foil to the outer wall will reduce it even further but the extra cost will not be worthwhile.
The outer wall should be 'thin' and the innerwall should be thick.
The outer wall will radiate heat out more quickly, although in Thailand the differences in temperatures during the day is not that big (small delta T).
Having an airflow in the space between the walls would replace hotter air with cooler air lowering the temperature even a little bit more and will prevent moisture buildup that can cause mold.
The innerwall functions as a heatsink. If you use airconditioning the innerwall cools down and will help to reduce temperature fluctuations between airconditioning cycles because of its thermal mass.

A good way to keep the house cool is to ensure a good roof overhang and lots of undercover out door terrace.

You could also use large egg trays they are good for 2 things insulation and soundproofing

[Kwasaki]

crazykopite, on 2012-02-09 11:12:28, said:

sezze, on 2012-01-29 21:39:11, said:

bankruatsteve, on 2012-01-29 21:03:54, said:

Superblock/Q-Con is the best value.

Best value on what points ?? Breeze blocks are way cheaper , and have near the same building time . Insulation value of the Q-con is the best , but doubling up the breeze blocks gives probably better value then the q-con . The prize difference is , even with doubled walls , still quite something . I do not see the value of the Q-con blocks .

breeze block you can go up 5 courses at a time super block you can keep going and going and going plus isulation is far better !!!!!

Your missing the point, costs are involved here and you still need beams to take the roof whatever you use.

[janverbeem]

qcon/superblocks are very porous so should not be used for outside walls in my opinion.

[David006]

necronx99, on 2012-01-30 14:48:51, said:

Naam, on 2012-01-30 06:48:30, said:

necronx99, on 2012-01-30 05:51:01, said:

Unmentioned advantage and disadvantage of the superblock.

If you are doing anything 'unusual' in the construction it is very easy to work and shape into curves and other shapes, similar to wood in many respects.
If you plan on hanging anything on the walls it is weak and special fixings are required, particualrly for heavy items like a plasma.

FAIRY TALE! NOTHING special required, walls are NOT weak! this is the second home i built with superblock, living in it since 6½ years, everything is fixed with normal wall anchors and screws including upper kitchen cupboards loaded with heavy crockery and glass items.

Happy stand corrected Naam, my lumpy brown friend.
If we are going to get along here you are going to have to accept the fact that quite often, I have absolutely no idea what I am talking about!

lol...

have all three types of bricks in our house..builder recommended the lightweight jobbies for the weight in upper level...then proceeded to build massive reenforced concrete lintels and frames for windows and doors .house is like a fricking bunker strength wise..to his credit though..happy happy.
Many may have noticed that the wall builders tend to fill in upper parts of a block wall with bricks at an angle..not sure if this is a method or just easier than cutting the blocks..?
I agree with Naam that the lightweight blocks are more than strong enough to support kitchen cupboards etc with good plugs and screw length...it is shear force after all ...Bigger problem with the hollow blocks as no holding area for plugs once into cavity..cavity butterfly bolts are probably the answer there...

When we bought our lightweight blocks they told us we needed specially formulated cement ( more expensive of course!)..bought a load and then run out ..could not source any more so used regular green bag cement....seemed okay..go figure.

Gonna brick in another part of the under-house area for another bedroom and a workshop ( toy box as the wifey says)...using cheap blocks...houses ain't Stradivarius violins they is just boxes to keep the rain out after all..

re keeping a house cool...we planted banana trees ...better than an umbrella and you can eat the fruit

[canopy]

I've been reading through this topic. Is a correct synopsis that AAC blocks offer every single advantage and traditional bricks and blocks are disadvantageous in every way and anyone who doesn't use AAC for all interior and exterior walls is making a misinformed choice?

[necronx99]

canopy, on 2012-02-11 07:48:18, said:

I've been reading through this topic. Is a correct synopsis that AAC blocks offer every single advantage and traditional bricks and blocks are disadvantageous in every way and anyone who doesn't use AAC for all interior and exterior walls is making a misinformed choice?

It is a superior product in all respects except (debatable) price.

[Gary A]

A friend of mine is adding on to an existing house. I got a first hand experience of the insulating qualities of the white light weight blocks and the common small red bricks. Neither wall was yet rendered. With the sun shining brightly on the outside of the wall, the red bricks were actually hot to the touch while the insulating blocks felt the same as the room temperature. I would think that the insulating blocks should be used for rooms that will be air conditioned.

[Naam]

janverbeem, on 2012-02-11 01:13:01, said:

qcon/superblocks are very porous so should not be used for outside walls in my opinion.

that is correct but applies only to those who run out of money and can't afford plastering

[Naam]

crazykopite, on 2012-02-09 11:29:06, said:

A good way to keep the house cool is to ensure a good roof overhang and lots of undercover out door terrace.

and the best way to keep a house cool is to provide ~600btu/h aircon cooling capacity per m²