Concrete Slab Floor

[AjarnRichard]

We are going to construct an 11mt x 7 mt x 70mm concrete floor slab. [6 cubic meters]

Any suggestions about the approximate cost of materials? Cost of labour? We will use CPAC cement to deliver premix.

I was quoted Baht 90,000 for the whole job..

Richard

[Kwasaki]

Your last post at costs 90,000 seemed OK but 90,000 seems to have got stuck on the brain of your builder .

90,000 for whole job what is exactly involved ?, sounds high to me for a concrete slab, off the top of my head 20,000 to 30,000 wouldn't be far out.

6 cubic meters I wouldn't think was enough either depending on what it is being use for, I would say you will want 8 cu because concrete floor slab thickness for residential construction is usually 100mm, 125mm to 150mm is recommended if the concrete will receive occasional heavy loads.

What size high tensile deformed bar are you using ?.

Ditto..........Mild steel bar ?.

Do you have to buy timber for shuttering ?.

Most resent one I remember was CPAC 180 steng, 12 or 13 cu @ 1800 bht per cu, I think some have paid as much as 2100 bht, the price sometimes depends where you live and how far you are from the ready-mix mill.

And useful info from " bbradsby ". I wouldn't let ready-mix concrete onsite more than 1.5 hrs after the mill time stamp ( if there is such a thing in Thailand ) and look for water added by the truck driver always, but especially if youre getting close to that time limit.

I would add there's temperatures to consider and out of direct sun drying.

Edited February 20, 2012 by Kwasaki

[AjarnRichard]

Thanks so much Kwasaki.. this helps alot!

I should inform that I am unfortunately working from remote right now. I am helping to improve the house of my fiance, but leaving a lot of the decisions to the "family". As you saw in my other post, we raised the house. That was essentially to start the process to build a bottom floor and then we will enclose it later on. Nothing heavy will go on the floor more than people and furniture, but your point about the thickness is well taken. It might be that the cost of 90,000 will include the foundations as well, cause i realize now that the foundations, as far as I know did not exist. This was a wood house on stilts before, so we are kind of working backwards. So if the quote includes the foundations, then maybe that would account for the extra expenses.

Any other comments would be appreciated. It is so helpful to have people on this forum helping each other. Thank You.

[Kwasaki]

Thanks so much Kwasaki.. this helps alot!

I should inform that I am unfortunately working from remote right now. I am helping to improve the house of my fiance, but leaving a lot of the decisions to the "family". As you saw in my other post, we raised the house. That was essentially to start the process to build a bottom floor and then we will enclose it later on. Nothing heavy will go on the floor more than people and furniture, but your point about the thickness is well taken. It might be that the cost of 90,000 will include the foundations as well, cause i realize now that the foundations, as far as I know did not exist. This was a wood house on stilts before, so we are kind of working backwards. So if the quote includes the foundations, then maybe that would account for the extra expenses.

Any other comments would be appreciated. It is so helpful to have people on this forum helping each other. Thank You.

From your previous pictures I assume that the concrete slab floor will be installed under the house at ground level taking in all the concrete columns that have been put in place to raise the house.

The new columns should have piers which are the columns foundation, to dig out for a concrete slab or if the ceiling height is enough already, the preparation of the slab can be formed on the existing ground.

I don't want you to be ripped off and that is what it sounds like to me, in the first instance of raising the house OK but what you are about to have done now should be nowhere near the cost of 90,000. Regards K.

[AjarnRichard]

After your input, i tried to find out why this is costing so much... apparently they are talking about putting up concrete beams to strengthen the tie between the pillars...........

They want to link each pillar. : |

[janverbeem]

You can build a house with those dimensions for 90.000 Baht upcountry.I guess someone is taking you.

6 cubic 210 steng should be around 13.000 Baht,add another 1200 Baht for labour and 3000 for the reinforcement steel.

I think it's time to look for another fiance.

Edited February 20, 2012 by janverbeem

[AjarnRichard]

The house is in Surat Thani Province............... but I learned that this amount is not just for concrete slab, but is also for cement beams between the pillars.....

there are 24 pillars.......\

So you can build a house for Baht 90,000?? That is impressive...

Edited February 20, 2012 by AjarnRichard

[steve187]

You can build a house with those dimensions for 90.000 Baht upcountry.I guess someone is taking you.

6 cubic 210 steng should be around 13.000 Baht,add another 1200 Baht for labour and 3000 for the reinforcement steel.

I think it's time to look for another fiance.

so its 1168 baht per square metre to build a house upcountry

[sezze]

The house is in Surat Thani Province............... but I learned that this amount is not just for concrete slab, but is also for cement beams between the pillars.....

there are 24 pillars.......\

So you can build a house for Baht 90,000?? That is impressive...

No , you can build houses for half of that up country , but 90k is also possible ( and anything more also ) . This is not the same standard and size as yours but there are plenty of houses in Thailand build for less then 100k .

They are certainly squeezing you as 90k is very overinflated for this slab and at least 50% too much . Even with the beams etc , it would surprise me if it costs 45000 baht . As for a price breakup .

6m3 , at around 1700 /m3 = 10500 baht .

steel = depending on what size used , but somewhere between 2000 and 10000 baht .

So far i only got 20000 baht high ranking , but go even higher on the 25000 mark . The work involved is nearly 0 , but imagine clearing the land and level it and put up some casing to pour the concrete . That would be tops 1 day of work for 5 people , but i go overestimating at 2 days for 5 people . that's 2 days x 5 daily wages = 2x5x 500 baht ( nowhere they earn this amount ... probably half but i'm overestimating again ) = 5000 baht .

so 30000 would be a top ranking , and everything over 45000 is just a complete rippoff .

[Naam]

We are going to construct an 11mt x 7 mt x 70mm concrete floor slab.

a slab of that size with a thickness of only 70mm is "penny wise, pound foolish²" no matter how much steel reinforcement is brought in.

no offence meant!

[Kwasaki]

After your input, i tried to find out why this is costing so much... apparently they are talking about putting up concrete beams to strengthen the tie between the pillars...........

They want to link each pillar. : |

With respect I don't know what is going to convince you but the builder thinks you are a gravy train the perfect meaning for your situation.

This is what the other guys here are trying to say.

I have said already the new 24 columns ( pillars ) will have had a foundation or most certainly should have, so you do not need ground beams to tie them in, the columns ( pillars ) can easilly be linked to the floor slab with the reinforcement.

Here's a rough sketch :- Doc1.doc

Edited February 21, 2012 by Kwasaki

[Naam]

i like your sketch Kwasaki, but what i don't like is "loosely compacted granular fill" below the slab.

[bankruatsteve]

i like your sketch Kwasaki, but what i don't like is "loosely compacted granular fill" below the slab.

Yeah. Didn't he have some dirt filled in already? That should be enough. To the other point... I had 2 "builders" that started out OK but then got greedy (I did things by short term projects). I fired both of them and took the "builder" stuff on myself. Not without grief, but happy with the end product. Cheers.

[Kwasaki]

i like your sketch Kwasaki, but what i don't like is "loosely compacted granular fill" below the slab.

I did say rough but there was a reason for mentioning it, if you look at his pictures in his other thread the slab would have slopes all around it, and it was a recent infill so I thought achieving a suspended slab would be better way to go.

[AjarnRichard]

Dear Kwasaki and others on this thread.

I finally got to the bottom of this.. thanks also to your support. What they say they are doing, is first making concrete beams between each pillar, so 28 beams all together (in the ground). After the beams are in place, they were going to pour a concrete slab over the entire surface (7mx11m). I have made a rough sketch as attached. The sketch shows the pillars and beams before the pouring of the slab (Of course the slab will obscure the beams afterwards).

Do these beams make sense? .......... I think there are two main questions. The first is whether the costings are close or near close, and the second is whether this is technically sound or just overkill.

I hope you can offer your further opinions .... Thanks you....

Floor.doc

Edited February 28, 2012 by AjarnRichard

[jinjinswing]

Cannot comment on cost but you should refer to your engineer's drawings for the pier and beam layout size and steel, they are in place to support the structure, the new house that will sit on it.

you have a suspended slap on piers, formwork will be needed for the slab over the beams, 24 piers, excavation, material and labour...plus you had the site filled......just over 3AU grand for all that seems very cheap to me...wops i did coment...i think some of the other guys were building kennels, better to ask people who are actualy in the building business if you want constructive input.

One thing im sure of, as long as the builder followed the engineers requirments that structure is going nowhere.....looks very sound to me.

[bankruatsteve]

Dear Kwasaki and others on this thread.

I finally got to the bottom of this.. thanks also to your support. What they say they are doing, is first making concrete beams between each pillar, so 28 beams all together (in the ground). After the beams are in place, they were going to pour a concrete slab over the entire surface (7mx11m). I have made a rough sketch as attached. The sketch shows the pillars and beams before the pouring of the slab (Of course the slab will obscure the beams afterwards).

Do these beams make sense? .......... I think there are two main questions. The first is whether the costings are close or near close, and the second is whether this is technically sound or just overkill.

I hope you can offer your further opinions .... Thanks you....

Well, the columns that are already in place are supporting the overhead structure, yah? So, all those "beams" as you call them are for what? If all you are doing is putting in a slab below the house, I really don't think you need all that structure. As I said before, beware of "builders" getting greedy. Maybe time to fire this one and talk to somebody else.

[janverbeem]

Dear Kwasaki and others on this thread.

I finally got to the bottom of this.. thanks also to your support. What they say they are doing, is first making concrete beams between each pillar, so 28 beams all together (in the ground). After the beams are in place, they were going to pour a concrete slab over the entire surface (7mx11m). I have made a rough sketch as attached. The sketch shows the pillars and beams before the pouring of the slab (Of course the slab will obscure the beams afterwards).

Do these beams make sense? .......... I think there are two main questions. The first is whether the costings are close or near close, and the second is whether this is technically sound or just overkill.

I hope you can offer your further opinions .... Thanks you....

Well, the columns that are already in place are supporting the overhead structure, yah? So, all those "beams" as you call them are for what? If all you are doing is putting in a slab below the house, I really don't think you need all that structure. As I said before, beware of "builders" getting greedy. Maybe time to fire this one and talk to somebody else.

So you would lay an 11 meter long floor slab with any support under it other than earth?

[rgs2001uk]

Cannot comment on cost but you should refer to your engineer's drawings for the pier and beam layout size and steel, they are in place to support the structure, the new house that will sit on it.

you have a suspended slap on piers, formwork will be needed for the slab over the beams, 24 piers, excavation, material and labour...plus you had the site filled......just over 3AU grand for all that seems very cheap to me...wops i did coment...i think some of the other guys were building kennels, better to ask people who are actualy in the building business if you want constructive input.

One thing im sure of, as long as the builder followed the engineers requirments that structure is going nowhere.....looks very sound to me.

Excuse me while I pick myself up off the floor,

"as long as the builder followed the engineers requirments"

This is Thailand we are talking about, last week Somcahai was driving a tuk tuk in Bkk, this week he is a civil engineer.

Last week Somboon was a rice farmer this week he is a stuctural engineer.

Have a look at the OPs other post, take a look at the house, now ask yourself, do you really think there was ever any engineer involved in this "back of a fag packet" wonder of engineering.

Just over 3 grand Aus is totally irrelevant, the OP doesnt live in Aus he lives in Thailand, and is being taken to the cleaners, this is total overkill.

[bankruatsteve]

Dear Kwasaki and others on this thread.

I finally got to the bottom of this.. thanks also to your support. What they say they are doing, is first making concrete beams between each pillar, so 28 beams all together (in the ground). After the beams are in place, they were going to pour a concrete slab over the entire surface (7mx11m). I have made a rough sketch as attached. The sketch shows the pillars and beams before the pouring of the slab (Of course the slab will obscure the beams afterwards).

Do these beams make sense? .......... I think there are two main questions. The first is whether the costings are close or near close, and the second is whether this is technically sound or just overkill.

I hope you can offer your further opinions .... Thanks you....

Well, the columns that are already in place are supporting the overhead structure, yah? So, all those "beams" as you call them are for what? If all you are doing is putting in a slab below the house, I really don't think you need all that structure. As I said before, beware of "builders" getting greedy. Maybe time to fire this one and talk to somebody else.

So you would lay an 11 meter long floor slab with any support under it other than earth?

Yeah, just tie into the existing columns with rebar.

[wayned]

You say that you are going to close it in later. A 70mm slab won't support your walls, no matter how much rebar you use. Your drawing is pretty muchs how I built my house. Each column, 34 of them, are tied together with "footings" and rebar. They are space 4 meters apart. I used prepoured concrete slabs on top of the footings and then poured another 70mm of concrete on top of that with wire mesh. Didn't have the luxury of ready mix, everthing mixed by hand in the front yard. Still have a few cracks in the exterior walls, but none in the floor. Couldn't put a price on it at todays prices as I did it 12 years ago. My 2 cents worth is put in the footings.

Edited March 1, 2012 by wayned

[jinjinswing]

Hmmm mr rgs....any body that goes ahead with out drawings from certified structual engnieer and relying on his builder to "just know what to do" is a dam fool in any country......

[sezze]

Hmmm mr rgs....any body that goes ahead with out drawings from certified structual engnieer and relying on his builder to "just know what to do" is a dam fool in any country......

Hmm , did you ever build in Thailand ?? And if yes , was this a multi million project designed for a big company ( shopping mall / skyscraper etc ) or just a normal home ? I guess not ... You do have experience in the building business , but not in Thailand , or it has to be for a big company , but not in the rural towns . I guess you would face huge surprises when having your plan and give it to a Thai builder ( not the big companies ) , if you ever do ... please do not do crazy stuff and get your truckload of tranquilisers ready hahaha. Remember you are NOT in Australia .

[rgs2001uk]

Hmmm mr rgs....any body that goes ahead with out drawings from certified structual engnieer and relying on his builder to "just know what to do" is a dam fool in any country......

You are of course correct, however please dont expect to lay a western building standard template on top Thailand and expect it to apply to what takes place here.

Stick around this forum and read with horror some of the posts, many backed up with photos that stand as testament to what actually taked place out in the sticks.

I stood and watched as a worker was about to install a sink unit right next to a door, when this was pointed out, his answer, no problem the door opens outwards.

This was where two walls meet, or where the opposite meets the adjacent at point A on a triangle.

Other time saving skills include, knocking screw nails in with a claw hammer, watering down paint to make it easier and quicker to apply.

Dont even bother asking about earthing.

Welcome to house building in Thailand.

[Kwasaki]

After your input, i tried to find out why this is costing so much... apparently they are talking about putting up concrete beams to strengthen the tie between the pillars...........

They want to link each pillar. : |

With respect I don't know what is going to convince you but the builder thinks you are a gravy train the perfect meaning for your situation.

This is what the other guys here are trying to say.

I have said already the new 24 columns ( pillars ) will have had a foundation or most certainly should have, so you do not need ground beams to tie them in, the columns ( pillars ) can easilly be linked to the floor slab with the reinforcement.

Here's a rough sketch :- Doc1.doc

You must of missed this, I was here to help you in a professional way, what they are showing you is total overkill and I doubt if they would carry out the work to the drawing anyway, they trying to pull the wool over your eyes, this is my last reply, goodluck with it. .

situation floor slab.doc

Edited for " naam " approval.

Edited March 2, 2012 by Kwasaki

[jinjinswing]

hahaha i get the point....still because i am in the building indusrty i would seek out a desgin from someone who is qualified, no way would i allow some one to dream it up fo me, even i wouldnt do it and god knows how many places ive been involved with, unless its for something like a chicken shed....

And as far as labor and there skill level, thats a problem everywhere you can never over supervise.

I had the amusing experience of booking into a hotel in Chiang rai recently, my partner found it on the net and was advertised as something or other resort, only recently opened sounded good...little out of CR, we were picked up in brand new merc van, very flash and well appointed as you can imagine, so far so good, on arrival the building designed hardly jumped out of me 2 story rendered rectangle with a hip roof with around 12 to 16 rooms, not sure, then noticed the dining area, metal flat room with walls on 2 sides attached to the end of the building....hmmm ok country thai style, wanting to shower and shave the basin tap came off in my hands first time i touched it, water gushing out...we were given a new room further down, all the rooms were the same design, timber door opening out to a sealed balcony, the door was wider than the balcony, conduct running along walls to power points and air con...steping out to balocny conecting us to exit stairs looking up and along the walls....hmmm someone forgot to run a string line while laying the blocks...infills above celing height as roof was a skillion over balcony also ran some thing like hua hin beach does on a wind day, to say it was poorly build is an understament, there were many more examples of a farmer turned builder to see so i do know what you guys mean ive witnessed it too.

Thais are very capable of top quality you only need to go to some of the shopping centres, and ive seen some well put togther homes as well over the years, yeah i see you can have a problem finding a good crew up country but if i do decide to build here it wont be up country.

[janverbeem]

hahaha i get the point....still because i am in the building indusrty i would seek out a desgin from someone who is qualified, no way would i allow some one to dream it up fo me, even i wouldnt do it and god knows how many places ive been involved with, unless its for something like a chicken shed....

And as far as labor and there skill level, thats a problem everywhere you can never over supervise.

I had the amusing experience of booking into a hotel in Chiang rai recently, my partner found it on the net and was advertised as something or other resort, only recently opened sounded good...little out of CR, we were picked up in brand new merc van, very flash and well appointed as you can imagine, so far so good, on arrival the building designed hardly jumped out of me 2 story rendered rectangle with a hip roof with around 12 to 16 rooms, not sure, then noticed the dining area, metal flat room with walls on 2 sides attached to the end of the building....hmmm ok country thai style, wanting to shower and shave the basin tap came off in my hands first time i touched it, water gushing out...we were given a new room further down, all the rooms were the same design, timber door opening out to a sealed balcony, the door was wider than the balcony, conduct running along walls to power points and air con...steping out to balocny conecting us to exit stairs looking up and along the walls....hmmm someone forgot to run a string line while laying the blocks...infills above celing height as roof was a skillion over balcony also ran some thing like hua hin beach does on a wind day, to say it was poorly build is an understament, there were many more examples of a farmer turned builder to see so i do know what you guys mean ive witnessed it too.

Thais are very capable of top quality you only need to go to some of the shopping centres, and ive seen some well put togther homes as well over the years, yeah i see you can have a problem finding a good crew up country but if i do decide to build here it wont be up country.

You do realise that most,if not all ,of the quality shopping centers and hotels are designed by foreign architects,don't you.After that they most of the time are build by Thai companies who are under foreign management.

[AjarnRichard]

Okay... i got my answers and Kwasaki I deeply deeply appreciate your opinions and drawings on this... They have guided me and will now give me the ammunition I need to go forward.....

I appreciate everyones thoughts on this......... As I am new here in Thailand, I got a quick learning curve from this experience. While I will lose quite a bit of money on this matter, you all saved me from losing so much more.. so I feel i owe you alot.... I am thankful for this forum...........

End of thread......... (at least on my part)

[wayned]

Building walls on a concrete slab at a later date without proper footings is a recipe for disaster. Save a little now pay more later. My last 2 Satangs worth!

[linno2]

Any info on a moisture membrane under the slab - I have seen in other countries the use of plastic sheeting at the base of the slab - each strip of black plastic joined with a special adhesive tape - a bit like gaffers tape for those in the music industry. It is the standard approach in OZ and NZ for example and stops the rising damp as I understand. I asked today at Home Pro in Phi Mai and they could only direct me to a large roll of glad wrap - the sort used for wrapping furniture prior to storage or your suitacase at an airport as a security measure or for use as a painting drop sheet in Thailand. I have seen a lot of paint and render bubbling off walls in my own place and elswhere in Thailand (not related to plumbing problems) and was wondering if there were any first hand comments about this practie in LOS?