Floating slab using EPS Styrofoam/Polyst instead of sand

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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby developer3d » Sat Mar 13, 2010 7:44 pm

Just a quick update my waffle slab went down today

Picture attached of the formwork I ended up finding some steel shutters that they use on road works at where 250 mm deep an unexpected find

About the only hitch we had was the pole ceremony, kind of had the guy stumped when there wasn't any poles to try on to ... crazy farangs :) .... after much discussion he ended up settling on a place in about the center of slab.

modified-waffle-pod-slab.jpg


pole-ceremony.jpg


pour.jpg
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby brent roberts » Sun Mar 14, 2010 2:08 am

Hello from down under. I like your floating slab. Ive done a few here in NZ what we do around the outside footing is drill a 300 Dia. hole about 1.0 m deep every 2 or 3 meters which helps hold the slab to the ground. Also good to see a thick plastic under your concrete so many people dont put a vapour barrier under their concrete. The only thing I would worry about is the level from your floor to the outside ground. Have to agree with you about the vibrator its so important to vibrate concrete but not over do it.
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby developer3d » Sun Mar 14, 2010 8:08 am

Hi Brent,

Thanks for your feedback, I understand your point about the level of the "floor" to the ground but that's an optical illusion caused by the wide angle lens on my camera that I used so you can get the whole slab in one shot, my pocket camera lens means you can only get pieces or you need to get so far back that its lost in the distance. This shot might show the height to the ground better.

updated.jpg


As far as your strengthening holes go, I haven't heard of that before. The floating pod slab was developed in Australia in the 80's to prevent slab cracking on reactive soils, ie clay based soils that expand and contract when they get wet, causing "embedded" slabs to crack when they move with the soil expansion.

One of the many side benefits to this was speed of construction, insulating properties, and reduced costs over a traditional slab on ground or piers but the main reason you would choose this style in Australia at least ( not sure about NZ ) is the reactive soil, If I was building on slopping ground I would not chose this style of construction.

So although I understand the concept of the mini piers but that would embed the slab into the ground, locking it in place as you have said and negate its very purpose, maybe you used waffle for some other reason in NZ

I don't have highly reactive soil here in Thailand but I am building on an old rice paddy and we are still surrounded by working paddies on 3 sides that are flooded several times a year so my raised land has all the water it can drink for free :D one of the reasons for me doing this is method.

lift.jpg


I could not agree with you more about the vapour barrier :D
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby BKKBILL » Sun Mar 14, 2010 2:56 pm

“About the only hitch we had was the pole ceremony, kind of had the guy stumped when there wasn't any poles to try on to ... crazy farangs .... after much discussion he ended up settling on a place in about the center of slab.”

Good start looking forward to the continuation of the project,

If nothing else the Thai’s are flexible when it comes to ceremonies.
It's not who you know, it's whom you know.
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby dozer » Sun Mar 14, 2010 4:58 pm

Where is the plumbing pvc piping, inbound water + outbound flow?
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby developer3d » Sun Mar 14, 2010 6:20 pm

Because I am bootstrapping the build and doing all the actual building myself with just one full time laborer my design based around several small stand alone but interconnected buildings like you see in some resorts layouts.

This means I will be able to quickly finish enough to live in and then move in and chip away when I have time and loose change.

This type of design also means that the individual buildings requirements are quite small - eg the sala, home theatre building and my home office are all seperate stand alone buildings, as will the kitchen as it will be a stand alone outdoor kitchen sort of like this.

outdoor-kitchen.jpg


So the slab shown here for the bedrooms and a living / dining area and a bathroom.

I don't like too many pipes under the slab in case something goes wrong so I only have toilet out and bathroom floor drain in the slab, they are the back end of the photos displayed.

plumbing.jpg


The bricks we are using holes designed for steel reinforcement but also allow conduit - both electrical and water - to be run inside the wall "cavity"
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby thaifly » Sun Mar 14, 2010 7:31 pm

its a gidday to dev3...hey son..u are jumping the gun :D :lol: :D :lol: ..nice to see some pics of your finished sala :D can only catch a glimpse of its wing. :D :lol: its a ... smoky c/mai gidday to all..ITS THE THAIFLY FROM MAE RIM
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby developer3d » Sun Mar 14, 2010 10:35 pm

This is a construction zone and it will be for the for the best part of this year so it would be premature to finish the Sala now

The main reason I built it first is that it is some quick shade out of the Thai sun to work on the house which because it is bigger will take longer to provide any shade at all and when the house is finished I will turn this now work space into a leisure space.

DSCN0658.jpg


And yes I already know your opinion of fibre cement roofing sheets, you don't like them - so for anyone else these are the only affordable roofing material I have found in Thailand that you can get with a high TSR coating straight from the Manufacturer, as opposed to applying the coating aftermarket.

TSR stands for Total Solar Reflectance. This is the percentage measure of the amount of solar energy reflected from a given surface.

100% = Total Reflection.

So, 0% = No reflection, therefore 100% absorption.

The Fibre Cement Sheets I choose are coated to TSR 80 compare that of standard terracotta colored tiles and they have a TSR value of 17 ie 83 % heat absorption versus 20%

As would be expected they are a bit more expensive that regular fiber cement roofing sheets at 63 baht each for the 15 x 120mm size and the accessories like ridge caps are all 80 baht each, for those that dont like joins you can get this is 4.8 M lengths as well.

Although a bit of a sales pitch there is an explanation of TSR coatings here

http://www.heatreflectivecoatings.com.au/technical.php
http://www.coolpaints.com.au/cms.php?g_PageID=2

Manufacturers Website

http://www.mahaphant.com/

Coated Fibre Cement

http://www.mahaphant.com/en/our-products/product-hahaung-detail-color.jsp?prdid=55

Coated Cement Tile

http://www.mahaphant.com/bcknd/fnctn/dwn/dwn.jsp?fname=HaHuangGranadaKoolCatalog.pdf&fpath=/elctfl/mtrl/file94.pdf
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby jaytee » Mon Mar 15, 2010 11:54 am

developer3d wrote: the kitchen as it will be a stand alone outdoor kitchen sort of like this.

outdoor-kitchen.jpg



lovely western palivion styled kitchen :) would it last to the rigors of all weather conditions appears exposed to me including your land what about the predators they are a hungry lot seems they would have a great party there just crawl in no invitation needed :D not to mentioned the dogs they would be around pronto during the night having a sniff a wee and a poop :oops: just my thoughts :D :D :D
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby developer3d » Mon Mar 15, 2010 1:08 pm

Hi Jaytee

Your concerns are certainly good factors to consider into the design.

As I am sure you know many Thai style houses have outdoor style kitchens, granted they are generally attached to the back or side of the house rather than separate buildings but this is one of the common Thai building concepts ( along with the toilet gun :D ) that I think is pure genius.

We are renting whilst we are building and this house has both an indoor and an outdoor kitchen, but the only cooker is outside against the wall along with the fridge a bench and a sink the arrangement suits me great we do all the cooking and food prep outdoors.

I am Australian by birth you might know that Australia is the hottest driest continent on earth,the east coast Sydney Melbourne Brisbane is very mild but once you go just a couple of hours inland west where I am from its a very harsh country that's one of the reasons I am so vocal about basic eco design.

In the area where I come from all new houses must by law have a rainwater tank, must have a grey water recycling solution, must have low flow shower heads, be fitted with low energy light bulbs, low energy rated appliances and minimal insulation levels are mandatory etc etc etc these are not cutting edge they are law and we all know that by the time things like this get passed into law they are no longer innovative and forward looking Governments and law makers are the last to act.

I understand that these things are out of the reach of affordable Thai houses but wish I saw more in the mid range and high end builds I am hoping to blend some of the local design with good responsible environmental design.

As far as the dogs go I will have to have a fence to keep my own dogs in so that will keep out the strays.

On that note if anyone is looking for a serious dog this is the only real working dog kennel in Thailand that I have found so far, there is another in Malaysia, would be happy if anyone knew about any others, I am not looking for a show dog but a breed for purpose line.

http://www.siamcrowndog.com/
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby dozer » Tue Mar 16, 2010 9:18 pm

thread clean-up. flamish posts removed.
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby painless » Sun Oct 03, 2010 11:58 am

developer3d,
I am intent on building a 2 story house on a stiffened raft or waffle foundation using load bearing walls and a trussed roof. I would like to ask you some questions about my build and yours. If that is ok with you could you email me at maelstrom007 at gmail.com
Thanks
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby Maseratimartin » Mon Oct 18, 2010 3:13 pm

runker wrote:I bet that waffle slab would be great for a basement floor in cold climates too.



Exactly opposite!

In cold areas you usually poor foundations under all carrying walls...there are no columns as the walls are usually 30 and more cm thick and are able to carry the weight.
The foundation is deeper the colder it is....
On these foundations you poor a around 15cm thick slab with single layer of rebar mesh...

Option is a 20-30cm concrete slab with double layer of rebar mesh on a around 30-50 cm bed of rock stone....The slab is riggid and can move as a complete block on the stone bed.
=>That's why the waffel design will not work! It binds the slab to the ground....what you don't want! The slab must be extreme detailed constructed ....tolerances are about 1cm on 5m....

In Europe they use the double layer rebar concrete slab especially in areas where the ground is not stabile.

To the floating slab on Styrofoam:
It will be done in EU for isolation matters. The quality of the Styrofoam is very critical. Cheap products will collapse after the years and the slab breaks!
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby developer3d » Tue Oct 26, 2010 9:22 pm

<Dozer 10/26 slight edit to remove off topic comment>

I do need to comment here that you clearly don't understand waffle pod design, almost everything you said is incorrect, especially the point about the slab being bound to the ground - there a reason they call it a raft or floating slab, another a simple point in case.

To the floating slab on Styrofoam:
It will be done in EU for isolation matters. The quality of the Styrofoam is very critical. Cheap products will collapse after the years and the slab breaks!


The styrofoam is there only to form a void until the concrete sets, ( not even until it cures just an initial set ) after that the void forms have no other purpose.

To this end the original void forms where made from waxed cardboard, and there is work on trying to make the bio degradable on a personal level I am building them now with used car tires, which are free and plentiful and formed up and packed with dirt make a great void form.

Restating they only need to be strong enough to hold the weight of the concrete and the men placing it until the initial set. Your comment that they are somehow structural and the slab with break if they don't support it is rather naive if well intentioned.
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Re: Floating slab using EPS Styrofoam/Polyst instead of sand

Postby Maseratimartin » Sun Oct 31, 2010 2:56 pm

Dear developer3d,

The floating slab on styrofoam....is not the same as the waffel design.
In Germany we call this floating slab "Estrich" and it is around 5 cm thick. If the styrofoam underneath collapses....the slab will get cracks like cracy!

The waffel design concrete slab is in my opinion a cheap chary version....the waffel inserts are only to safe concrete.

To get a self carrying conrete slab it is very important to have a continious thickness and 2 layers of rebar!
I supervised to times back in Germany (and EU) many concrete slab works like for the Audi AG (Neckarsulm) and many others....up to 3000m3 concrete a day and I never saw such a waffel design....wonder who would sign such a static calculation?

To cold climates:
Think about from where the cold comes from when a house is build....from underneath? How it comes there...the cold comes from the sides....so then usually you make a foundation construction what you cover with styrodur foam plates so that the cold can even not come under the house.....

But good that we are a thai forum and we don't need to care about such things like cold and frost!
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