Wall Construction: Choices

[HeijoshinCool]

I'm building a 4 x 9 meter bungalow, two stories. Lower is a kitchen and living room (4 x 7) and a bathroom and office- both small. Upstairs is a bedroom and master bath. Flat roof, concrete floor.

Three choices in wall construction:

standard 2-1/2" block at 5 baht each; thicker, 5-1/2" block at 11 baht each; or, large gray stone at about 400 baht per cubic meter (this might come down).

I'm already ruling out the thin block as inadequate, unless it's doubled. Any experience with this? Or should I just jump up to the 5-1/2" thick block?

I've used 9" thick block in the States, it's structural, no need for corner posts. What about here? Is the thicker cement block structural? If not, how many courses before I have to pour some concrete? Can I go right up to 3 meters without reinforcing? Do I need corner posts, or can I lap the corners. I would definitely pour the interior space with concrete.

The final option, stone, is about 12 baht per square foot of face, for the stone alone, making it comparable to the block, and it makes a thick wall, 15"-18", and is supremely strong. But, man, a lot of work, and stuccoing it will use a lot of cement.

Finally, for both the upper floor and the roof, I'll be using the concrete planks, so that needs to be considered in the above questions.

Thanks much for any suggestions.

Edited October 31, 2012 by HeijoshinCool

[HeijoshinCool]

Okay, maybe it's a holiday somewhere.

Let's try a simple yes or no question:

Are the 18 high x 40 long x 14 cm thick cement blocks structural?

[sirineou]

In Thailand I would not use them as structural for a couple of reasons.

One would be the inconsistent quality of the cement block.

The Block you are used to in the US is manufactured to strict specifications.Here the quality varies from manufacturer to manufacturer.

second reason is , in the US after you construct the structural block walls, you would use wood floor joists,because your partition walls are framed and drywall and lightweight. here in Thailand, unless you construct the second floor out of wood, you will need concrete floor beams.

and third, the local labor pool is not familiar with the techniques of using block as structural members.

so as I said, Easy and inexpensive enough to use concrete columns and beams as your structure and fill it in with the material of your choice.

Edited November 1, 2012 by sirineou

[prophet01]

Is there any particular reason for not considering a reinforced concrete frame design with block infill walls?

[HeijoshinCool]

Thanks, both of you. Good points on the labor, so I'll be doing most of it myself with a couple of lifters and mixers.

I'm working on an AutCAD drawing now, doing a section of a typical wall. I'm thinking of using the 2-1/2" thick block, with a 7" space in between. Rebar through the monolithic slab, up into the 7" space, and fill with concrete. Gives a good place to carry the plumbing, too. I'm trying now to come up with a mechanical method, using local material, to join the two "walls" so compression doesn't blow them away from each other.

Going to stay single story. 12" thick walls will be structural, and have a nice appearance, as well as the sound insulation I'm looking for.

[cooked]

I have the same thing to think about. In my case however the first wall is already built and I am adding the second one for insulation, very important. I won't be filling the gap for this reason. Brickies used to make wall ties out of sturdy wire tied in an eight shape.

"90 cm horizontal, 45cm vertical for all cavities. Wall ties shall also be provided, spaced at not more than 30cm apart ,vertically , within a distance of 22.5cm from the vertical edge of all openings, movement joints and roof verges".

I think that the Q-blocks are structurally sound but there are different manufacturers now, so quality will vary.

I myself will probably have to use screws, but I haven't actually seen any 15cm long screws in Thailand as far as I can remember.

[HeijoshinCool]

I have the same thing to think about. In my case however the first wall is already built and I am adding the second one for insulation, very important. I won't be filling the gap for this reason. Brickies used to make wall ties out of sturdy wire tied in an eight shape.

"90 cm horizontal, 45cm vertical for all cavities. Wall ties shall also be provided, spaced at not more than 30cm apart ,vertically , within a distance of 22.5cm from the vertical edge of all openings, movement joints and roof verges".

I think that the Q-blocks are structurally sound but there are different manufacturers now, so quality will vary.

I myself will probably have to use screws, but I haven't actually seen any 15cm long screws in Thailand as far as I can remember.

Air space for insulation, I understand, but I'd like the strength of a pour. Who's Brickie? I was considering using sections of the heavy wire mesh, used in slabs, to tie the interior and exterior walls together, and the same block, 7" high, laid on side as spacers. I've checked them, they look to be pretty, though not perfectly, consistent.

[cooked]

Brickie is (or was when it was still real job) a bricklayer in the UK.

Yeah, you are right, you can insulate internally afterwards if you want. The Thais will tell you it can't be done, I am in fact doing something similar with a low garden retaining wall. I hope you get good quality concrete, tell them you won't accept concrete that has the consistency of soup. Come to think of it, I haven't seen or heard a concrete vibrator since I got to Thailand, I use a vibrating sander .

[sirineou]

Thanks, both of you. Good points on the labor, so I'll be doing most of it myself with a couple of lifters and mixers.

I'm working on an AutCAD drawing now, doing a section of a typical wall. I'm thinking of using the 2-1/2" thick block, with a 7" space in between. Rebar through the monolithic slab, up into the 7" space, and fill with concrete. Gives a good place to carry the plumbing, too. I'm trying now to come up with a mechanical method, using local material, to join the two "walls" so compression doesn't blow them away from each other.

Going to stay single story. 12" thick walls will be structural, and have a nice appearance, as well as the sound insulation I'm looking for.

I have seen vibrators at most of the big improvement stores , II think I see one At Thai Wasadu in Khon Kaen for about 1500 bht

Using 2.5 inch double wall for a single story home should work well,but a 7 inch cavity + 2.5 inch +2.5 inch + render, would give you a wall more than 12 inch thick.if I went that direction I would reduce the cavity to 3 inch ending up with a 8 inch thick wall, and I would not pour the whole cavity m but only 4x4 sections every 3 m or so in essence creating 4x4 columns inside the wall, and I would pour a ring beam under the windows, a lintel over the windows and an other ring beam on top of the wall where you can tie your roof in.

you can tie the two walls together by bending rebar in a U shape and burring it in the cement used to tie the block together (pointing). the U shaped rebar together with the columns and ring beams should make for a strong wall. see picture below

Or I would try to find 8 inch wide block, I know they are difficult to find, but I have seen others use it in Chiang Mai so they are available. and use the space inside the block to pour defacto columns.

then fill the remaining spaces with insulating material, I had seen a video where they used a if I remember correctly,

Burned coconut husk material, purchased at the local gardening center, very inexpensive, and inert. I looked for the video but could not find it, so don't quote me on the coconut husks, It could had being burned coconut shells or a similar material.

[cooked]

Vibrators: good news that they can be found, but I meant on building sites.

[HeijoshinCool]

Thanks, both of you. Good points on the labor, so I'll be doing most of it myself with a couple of lifters and mixers.

I'm working on an AutCAD drawing now, doing a section of a typical wall. I'm thinking of using the 2-1/2" thick block, with a 7" space in between. Rebar through the monolithic slab, up into the 7" space, and fill with concrete. Gives a good place to carry the plumbing, too. I'm trying now to come up with a mechanical method, using local material, to join the two "walls" so compression doesn't blow them away from each other.

Going to stay single story. 12" thick walls will be structural, and have a nice appearance, as well as the sound insulation I'm looking for.

I have seen vibrators at most of the big improvement stores , II think I see one At Thai Wasadu in Khon Kaen for about 1500 bht

Using 2.5 inch double wall for a single story home should work well,but a 7 inch cavity + 2.5 inch +2.5 inch + render, would give you a wall more than 12 inch thick.if I went that direction I would reduce the cavity to 3 inch ending up with a 8 inch thick wall, and I would not pour the whole cavity m but only 4x4 sections every 3 m or so in essence creating 4x4 columns inside the wall, and I would pour a ring beam under the windows, a lintel over the windows and an other ring beam on top of the wall where you can tie your roof in.

you can tie the two walls together by bending rebar in a U shape and burring it in the cement used to tie the block together (pointing). the U shaped rebar together with the columns and ring beams should make for a strong wall. see picture below

Or I would try to find 8 inch wide block, I know they are difficult to find, but I have seen others use it in Chiang Mai so they are available. and use the space inside the block to pour defacto columns.

then fill the remaining spaces with insulating material, I had seen a video where they used a if I remember correctly,

Burned coconut husk material, purchased at the local gardening center, very inexpensive, and inert. I looked for the video but could not find it, so don't quote me on the coconut husks, It could had being burned coconut shells or a similar material.

I really like the thicker wall; it looks great, the windowsills are deep (over the kitchen sink, on the sill, I'll build in a drying rack), and even better insulation. Hey, great idea and money saving, too, about the coconut. Lady next doors burns a truckload everyday. I'll start saving it. Yes, I'd planned on filling about every meter or two with concrete for strength, but hadn't come up with the coco husk idea. Are you SURE it's inert? Not going to rot?

Anybody else used husks as insulation?

[cooked]

I only heard about charred rice husks being used. I suppose you could spray it with fungicide / insecticide. Why not just buy insulation?

[sirineou]

I only heard about charred rice husks being used. I suppose you could spray it with fungicide / insecticide. Why not just buy insulation?

Now that you mention it , it could had being rice husks, They used it because it was very inexpensive and easy , to pour in the cavity as the went up, and they said it provided excellent insulation.

Like I said I had seen it used in a video,they filled the cavity in the block with it. ,it said that it was inert and could be purchased at any garden center very inexpensive .

[HeijoshinCool]

I only heard about charred rice husks being used. I suppose you could spray it with fungicide / insecticide. Why not just buy insulation?

Now that you mention it , it could had being rice husks, They used it because it was very inexpensive and easy , to pour in the cavity as the went up, and they said it provided excellent insulation.

Like I said I had seen it used in a video,they filled the cavity in the block with it. ,it said that it was inert and could be purchased at any garden center very inexpensive .

I'll check into it. Sometimes their ideas are brilliant and effective, sometimes ....

I'd hate to assume and have some toxic mold start growing in my walls! Maybe I'll just use air. It's free!

[bbradsby]

yes, even on rural sites in Thailand can you find cute girls wielding big honkin' vibrators for their concrete. I insist on these for my projects!

OP, you're talking about a lot of weight in concrete & block, upstairs bathroom, waterbed for all I know, lousy CMUs rampant all over Thailand... and we have no idea of the loading distribution upstairs and the roof, nor how the load paths work out from just a general post. Structural engineers are reeeallly cheeeaapp insurance in Thailand, and you'll sleep so much better knowing it's not going to come crashing down on you in your sleep. Just saying. In any case if ya know what your doing, have at it. If you want a structural engineer, PM me!

[extexthai]

Two things....first of all, be careful of over-vibrating concrete...I have seen many a form explode from over vibrating...it compacts the concrete too much and the form can not hold (This was on big industrial jobs stateside, long ago). I just used my 16oz hammer on the columns and bottoms of beams I could get to. It worked out fine....no honeycombs. I myself went with AAC block and the small red brick and am so happy with it. It saved me from installing AC, so far...and it has been 3 years since we built our house. Secondly, the burnt coconut husks/shells are highly sought after for making water filters that can take out heavy metals, pesticide and herbicide residue, so probably is very inert. Good luck. ett

[HeijoshinCool]

Two things....first of all, be careful of over-vibrating concrete...I have seen many a form explode from over vibrating...it compacts the concrete too much and the form can not hold (This was on big industrial jobs stateside, long ago). I just used my 16oz hammer on the columns and bottoms of beams I could get to. It worked out fine....no honeycombs. I myself went with AAC block and the small red brick and am so happy with it. It saved me from installing AC, so far...and it has been 3 years since we built our house. Secondly, the burnt coconut husks/shells are highly sought after for making water filters that can take out heavy metals, pesticide and herbicide residue, so probably is very inert. Good luck. ett

When you say, AAC block, is that the typical block here? It looks as if its been autoclaved, but, of course, no one that sells it in my town, knows what I'm talking about. I say oven, no one's ever seen an oven. I say cooked, heated, I get blank stares.

Or are you referring to Superblock? Where did you use the red brick?

Wonder if I could use the coconut, somehow, in-line from my pump?

[extexthai]

Two things....first of all, be careful of over-vibrating concrete...I have seen many a form explode from over vibrating...it compacts the concrete too much and the form can not hold (This was on big industrial jobs stateside, long ago). I just used my 16oz hammer on the columns and bottoms of beams I could get to. It worked out fine....no honeycombs. I myself went with AAC block and the small red brick and am so happy with it. It saved me from installing AC, so far...and it has been 3 years since we built our house. Secondly, the burnt coconut husks/shells are highly sought after for making water filters that can take out heavy metals, pesticide and herbicide residue, so probably is very inert. Good luck. ett

When you say, AAC block, is that the typical block here? It looks as if its been autoclaved, but, of course, no one that sells it in my town, knows what I'm talking about. I say oven, no one's ever seen an oven. I say cooked, heated, I get blank stares.

Here it goes by the brand names of Superblock, Q-con, etc. Just about any company into concrete products have a version of it. It is not only structurally sound, but it has thermo properties that insulate quite well, both heat and sound. It is very porous, so it has to be used with a non-porous course first.

Or are you referring to Superblock? Where did you use the red brick?

I used the red brick on the inside to alleviate those annoying half-columns sticking out of the exterior walls. It worked out to be a double wall with a dead airspace inbetween.

Wonder if I could use the coconut, somehow, in-line from my pump?

There are sites to go to that tell you how to make one of those water filters. Google it....I can't remember exactly. PM me if you want pictures.

[sirineou]

Ok I found the site where they used concrete block for load bearing walls and the material they used for insulation inside the block cavity is burned rice husk

I am not sure is I am allowed to post a link to the forum where this build was posted.

Edited November 10, 2012 by sirineou

[HeijoshinCool]

Thanks guys! I'm making progress ...