whats better? Pour CPAC Floor or Concrete Prefab Sheets

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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby MGV12 » Sun Dec 19, 2010 4:08 pm

fredlk wrote:
MGV12 wrote:The slabs I used on my ground floor are pre-stressed hollow core ... 8cm thick x 60cm wide and come in a variety of lengths.

Is there no resonance or vibration because of the hollow core and the lesser thickness?
I am not sure what is used in the house I'm in but it is built to a high standard and even so I can hear if somebody is walking on the floor above.


That I couldn't tell you really from personal experience. My upper floor is above the car parking area and sala ... due to a greater span the slabs are 10cm thick ... there is a gyproc suspended ceiling under that area and you certainly don't hear anyone walking across the floor in the bedroom or bathroom/dressing room that share that space. No way of knowing how it would be in the confined space of a room below but I would suspect it would not be a problem; certainly no worse than with a poured concrete floor over solid planks and maybe better due to the trapped air in the hollow core.

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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby MGV12 » Sun Dec 19, 2010 5:56 pm

BKKBILL wrote:
MGV12 wrote:If you compare the cost of a solid floor ... dirt .... labour to lay and compact dirt ... steel rebar mesh ... damp proof membrane ... CPAC [type] concrete .... labour to lay the concrete ... you would find that the price difference is no big deal and has in my opinion considerable advantages. It is of course considerably cheaper than using solid planks and a poured floor.


Now this I didn't know, just assumed a pour of concrete would be used above the pre-stressed hollow core planks. Delivered, installed and at a good price 260 Sq. M. Thanks for that the supplier isn't far from my upcoming build, or so I've heard. Think I know what my sub-floor will be. :mrgreen: :mrgreen:


My headman/contractor tried hard to get me to do a "topping", or as he referred to it a concrete pour, over the slabs as he had no experience of them and assumed it was needed. Being as I am a qualified engineer and had ordered these slabs according to the tech spec from the manufacturer I resisted his pressure ... the slabs plus a thick-bed layer of cement on which the tiles/marble/granite are bedded is perfectly adequate ... on whichever floor you use them.

If you are using this method on a balcony, that will be open to the rain, you will need to use cement with a waterproof additive when bedding the tile ... or a bituminous sealer or equivalent applied to the hollow core planks first. Waterproofing needs are the same as with a concrete pour over solid planks.

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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby geordie » Sun Dec 19, 2010 6:13 pm

MGV12 that sounds like a thin floor we use similar over here (uk) with hollows but a lot thicker slab 150-200mm now when i was looking through the archives i found one floor being installed and they were wellding the rebar out of the planks together
I am curious as to how yours are locked together if you are tiling directly as i have always seen concrete or joints filled with sand cement to create a solid slab effect

i did a preview and it did not go blue but somtimes this has happened before and posting went blue(link)later

BKKBILL wrote:
geordie wrote:(sorry bill i know it upsets you seeing my incompetence)


Oh dear here we go again. No worries geordie but just for your information there is a preview button right next to submit. If you would take the time checking your post before sending posting errors could be reduced. After now some 965 posts I thought it would be obvious.

Most builds here in BKK are now precast slab floors. The exception being bathrooms these are one pour slabs with fill and a vapour barrier installed under the pour to prevent moisture wicking.

Both ways are acceptable. The house I am now in has precast slabs on both upper and lower floors one advantage is no contact with the earth, another is insect control under slab is possible.

Here are a few pictures showing different methods there are many more that can be found in our photo gallery and those that are still building.

My next build will be all precast slab.

.


around any large city i would imagine fill dirt would become expensive due to higher transport
cost and lack of availability more so the sludge that is under BKK i have only experienced it
driving past the new motorways/bridges around BKK and it looks like black silt

Thanks mgv12 you sneaked one in while i was asking and answered the question the slabs are getting a screed/effect under the tiling
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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby MGV12 » Sun Dec 19, 2010 7:40 pm

geordie wrote:Thanks mgv12 you sneaked one in while i was asking and answered the question the slabs are getting a screed/effect under the tiling


I always try to sneak in an answer to the question before it's been asked .......

The sides of the planks are shaped to form a key-way when aligned, into this you apply a cement grout which, when set, prevents any vertical fluctuations between adjacent planks. For added lateral security you can expose the rebar and weld plates between the slabs. Ours were located by casting a concrete apron ring around the outside edge of the installed area. If that doesn't make sense I can maybe find a pic. Then, as you noted, you do in fact lay an homogeneous layer over the top of the slabs by using a thick-bed mortar for the tiles/marble/granite.

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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby fredlk » Sun Dec 19, 2010 8:20 pm

MGV12 wrote:The sides of the planks are shaped to form a key-way when aligned

And a key-way is .... ?
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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby Max&Bee-in-CM » Sun Dec 19, 2010 9:19 pm

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It's just the start ........
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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby geordie » Sun Dec 19, 2010 9:31 pm

a slot or groove cast so as to interlock the same as you would find on wooden flooring fred
the normal concrete planks are reliant on the concrete you pour over them to bind them together so any single plank you stand on will flex however as you know spread thet weight evenly over six planks they will support the load better
as mgv12 was not planning on a concrete pour the slabs he used interlock giving the same effect binding them and as the way they lay tiles over there is on a thick bed of cement this too will bind the slabs together giving a very strong rigid floor not common over here *UK) on domestic installs because you would not be wanting to move the slabs without a heavy crane
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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby fredlk » Sun Dec 19, 2010 9:39 pm

geordie wrote:a slot or groove cast so as to interlock the same as you would find on wooden flooring fred

Thanks geordie. Tongue and groove is a term I know.
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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby MGV12 » Sun Dec 19, 2010 10:02 pm

fredlk wrote:
MGV12 wrote:The sides of the planks are shaped to form a key-way when aligned

And a key-way is .... ?


See the diagram towards the bottom of the page in this link ...http://pccnew.pcc-concrete.co.th/index. ... c-80-x-600 ... they describe it as a shear key [same same]. When filled with grout it acts in shear ... locking the two planks together against vertical movement one to the other. Key-way as in locking or shear-key as in acting in shear.

The diagram shows the planks with a topping, complete with mesh, but this is optional and only really required where very heavy point loads are imposed; for example in a factory with machinery. All fun this engineering stuff isn't it Fred?

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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby kknaj » Sun Dec 19, 2010 10:52 pm

I can see why you would use the prefab concrete planks or hollow core planks in Bkk due to the ground issues there. I can see why you would use it on raise floors for under house cavities as well as 2nd floors. But for 30-40cm high foundations it wouldn't be very economical for a simple cost effective build.

But its good data to have as i wasnt aware of those issues with the bkk ground. Also when fill dirt becomes too expensive for inner city areas I can also see why you could save some money. For the typical build in the outer parts of thailand I dont think thats an issue for now.
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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby BKKBILL » Sun Dec 19, 2010 11:03 pm

Here is the web site for pcc concrete

http://pccnew.pcc-concrete.co.th/index. ... -core-slab
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Screen shot 2010-12-19 at 11.00.22 PM.png (250.06 KiB) Viewed 1291 times
Screen shot 2010-12-19 at 10.52.55 PM.png
Hollow core slab
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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby Treysd3 » Fri Dec 24, 2010 7:31 am

IMG00179-20101222-1329.jpg
Finished Concrete Floor
Hello

The Concrete Slabs were put in and then they put a Mesh in and then poured the Concrete. From what I can see it turned out good.
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Pouring the Concrete over the Concrete Sheets
IMG00144-20101220-1656.jpg
Entrance to House with the Concrete Slabs in
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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby kknaj » Fri Dec 24, 2010 10:15 pm

Great the project i moving along nicely :)

How many centimeters of cement did they pour on top of the prefab slabs?

What was the total m2 and cost of the slabs?

Also how many cubic meters of cement did they pour on afterwards?

This data will be handy for myself and others to calculate for the future ;)
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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby Treysd3 » Fri Dec 31, 2010 8:32 am

kknaj wrote:Great the project i moving along nicely :)

How many centimeters of cement did they pour on top of the prefab slabs?

What was the total m2 and cost of the slabs?

Also how many cubic meters of cement did they pour on afterwards?

This data will be handy for myself and others to calculate for the future ;)



As soon as I know for sure I will let you all know.. Ok :)
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Re: whats better? Pour CPAC Floor or Concrete Prefab Sheets

Postby geordie » Sun Jun 12, 2011 6:44 pm

bump
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