What to mix with cement to make waterproof concrete?

[khunPer]

If I can add another somewhat related question:

can anyone recommend a local brand of a sealant for bathroom tiles? (with pix if possible)

I find the recommendations of shop staff to be pretty unreliable....

Thanks!

I've used Crocodile (not sure if it's a local Thai product) with excellent results for indoor. Little more expensive than the cheapest brands, but may be worth it.

For outdoor I have used both Crocodile Swimming Pool grade and (German) Weber pool-grade. If you need for outdoor, I can take pictures, have a spare bucket of each. They are quite a bit more expensive than normal (indoor) quality.

[Sheryl]

Thanks, but that seems to be a grout. I want a sealant to apply over tiles that are already affixed with grout. Silicon based from what I read...

[MaiChai]

I have seen Thai builders soak the ground in a chemical that is supposed to keep bugs at bay for 10 years, before laying concrete. That stops bugs and stuff getting through the concrete (Thai style: thin concrete to save money and effort).

If u want to stop bugs getting into your house, fill all the gaps where they can fly in. Having lots of gekos also helps! We are pretty bug free after filling all the gaps.

Mind u gaps in the roof are a good thing as it lets heat out. Like all engineering things its playing off compromises.

[khunPer]

Thanks, but that seems to be a grout. I want a sealant to apply over tiles that are already affixed with grout. Silicon based from what I read...

Sorry, I'm not native English speaker, and using a dictionary gave me the Danish word for tile grout (fugemasse).

I've been using a Thai Product, Draga Water Seal, for extra water-seal of grout (only) on my roof terrasse, it's a non-toxic water-based product (label don't say if it's latex or silicone or...)

It's supposed to be spayed or rolled or brushed over roof or bricks or titles. First time I used a very tiny brush, but five years later, a few month ago, I was lazy a used a wider brush, splashing some of the water-seal on the tiles (that should be water proof itself). It looks like dirt or... is setting into the water-seal – the darker "lines" outside the grouted tile separation – or I have done something completely wrong...

(Seems like I will have a little extra job cleaning up my mess; not worth being lazy)...

Here is the label, hope that may help you.

[kannot]

Concrete is never waterproof. You have to seal it. It's really important to work the concrete to compact it and force out tiny air bubbles. This can be done with trowels.

In the West when making swimming pools the concrete is applied by spraying under fairly high pressure, and then worked soundly with trowels. It is either sprayed as a dry mix with water being added at the nozzle ("gunite") or as a wet mix simply blasted under pressure ("shotcrete"). It can be applied by hand with trowels but they have a bunch of guys really working it hard with trowels to compact it. I have never seen a swimming pool being "poured" in the USA.

The more the concrete is worked and compacted and air driven out, the stronger and more water resistant it will be. Then when it cures you can apply a sealer.

Cheers.

Dont mess about with trowels get one of these theyre cheap 2000baht or so

[maderaroja]

Dont mess about with trowels get one of these theyre cheap 2000baht or so

Well, it is cute. But, what is it's name and where can you get one?

[ThaiKneeTim]

You cannot make concrete which is completely waterproof but you can reduce it's permeability by about 70%.

There are two options, a concrete admixture or a paint on sealer. Admixes are the only long lasting solution.

There are four types of admixture, latex is the worst as it does not fill cracks that appear after pouring. The third from best is adding silicates to the mix to increase density, this helps but not that much. The second from best is a hydrophobic admix such as soap which can reduce water ingress by about 50%.

But the best by far is a hydrophilic crystalline admixture, such as this one from Xypex.

http://www.xypex.co.th/index.php?option=com_content&view=article&id=25&Itemid=137

That is the best, but that's what we use for tunnels and the like, for a shallow trough as I imagine you are making, just regular concrete will be fine as long as it is reinforced, I would suggest some fibers in the mix as well as steel reinforcing.

Top post on the subject.

I worked in civil engineering building water treatment works, and yes there are admixes available, shelves full of them at Global House. Water retaining structures are built using cement that has the sedative, swimming pools, water towers, treatment ranks, etc.

As already stated, just adding the proofing agent to the mix isn't enough on its own, the concrete has to be properly vibrated to expel air bubbles. The spaces left by bubbles in cured concrete are the easiest route for moisture.

Contrary to popular myth concrete doesn't dry, it cured. The curing process is a chemical reaction, made stronger during the curing process by keeping it wet for as long as possible after pouring. Frying too quickly will leave a weaker concrete prone to crumbling.

The locals thought I was crazy for covering my concrete drive with Hessian and watering it for two days after pouring. My driveway shows no sign of cracking while local roads are crumbling, and I've had delivery tricks on my driveway.

I'm planning on building a basement to the new house, I'll be using the additive in the concrete mix to keep moisture out, I'll also be adding a membrane to the outside of the wall below ground level.

[ThaiKneeTim]

As indicated by some above, concrete when properly installed is fairly water-impermeable, if not "water-proof".

The problem is that it is often not properly mixed, with workers adding too much water to make it easier to mix, work, and flow. This actually weakens its eventual strength and lowers its impermeability.

The dryer the mix when poured (the less water), and assuming sufficient cement, the better, although this makes it harder to pour, to spread out, and to vibrate within the forms to get any air pockets to float up and out.

In addition, once it has hardened a few hours, it is important to keep its surfaces wet for a full month to continue the curing and strengthening process. This requires covering it with burlap and/or plastic and constantly wetting it down, and perhaps keeping the soil around it well-watered.

For obvious reasons of inconvenience and ignorance, this is often not done in Thailand and elsewhere. So some of the various coatings mentioned above would help. Concrete/gunite swimming-pool installers (and their websites) might have some useful advice and techniques on this. In fact, maybe you should hire one to install your "moat".

In UK civil engineering a test is carried out to determine the suitability of the concrete. The 'Slump Test' is a small sample of the premix delivery placed in a former, then the former is lifted off, rather like a bucket on a beach sandcastle. The amount that mix drops is measured; too much drop means it's too wet, not enough drop means it's too dry. Edited February 4, 2016 by ThaiKneeTim

[maderaroja]

Top post on the subject.

I worked in civil engineering building water treatment works, and yes there are admixes available, shelves full of them at Global House. Water retaining structures are built using cement that has the sedative, swimming pools, water towers, treatment ranks, etc.

As already stated, just adding the proofing agent to the mix isn't enough on its own, the concrete has to be properly vibrated to expel air bubbles. The spaces left by bubbles in cured concrete are the easiest route for moisture.

Contrary to popular myth concrete doesn't dry, it cured. The curing process is a chemical reaction, made stronger during the curing process by keeping it wet for as long as possible after pouring. Frying too quickly will leave a weaker concrete prone to crumbling.

The locals thought I was crazy for covering my concrete drive with Hessian and watering it for two days after pouring. My driveway shows no sign of cracking while local roads are crumbling, and I've had delivery tricks on my driveway.

I'm planning on building a basement to the new house, I'll be using the additive in the concrete mix to keep moisture out, I'll also be adding a membrane to the outside of the wall below ground level.

What is the rate of mixture of the Xypex? What does one do with the Xypex when the truck appears to dump a load of concrete?

[Langsuan Man]

Dont mess about with trowels get one of these theyre cheap 2000baht or so

Well, it is cute. But, what is it's name and where can you get one?

According to a Google Image search

Best guess for this image: vibrator for concrete

[maderaroja]

Dont mess about with trowels get one of these theyre cheap 2000baht or so

Well, it is cute. But, what is it's name and where can you get one?

According to a Google Image search

Best guess for this image: vibrator for concrete

So, no one really knows where to get one. Is that what you are saying?

[Langsuan Man]

According to a Google Image search

Best guess for this image: vibrator for concrete

So, no one really knows where to get one. Is that what you are saying?

If you can Google it, now that I told you what it is , you can find it

http://www.ebay.com/sch/Concrete-Vibrators/25248/bn_1521537/i.html

[kannot]

Global House/Thai Watsadu/Possibly HomePro

[khunPer]

Sheryl, I think is, what you are thinking of with silicone water protection:

Link to TOA Shield-1 Nano Silicone page (in Thai):

http://www.toahomeguide.com/productsolution/view_article.php?solution_id=6

[maderaroja]

Can someone please tell me how to get the Xypex into the concrete when the truck arrives?

[khunPer]

Can someone please tell me how to get the Xypex into the concrete when the truck arrives?

Try to ask the cement delivery company if they deliver it premixed – I ordered ready mixed in trucks from our local Cement Thai via the HomeMart shop...

[sometimewoodworker]

Dont mess about with trowels get one of these theyre cheap 2000baht or so

Well, it is cute. But, what is it's name and where can you get one?

According to a Google Image search

Best guess for this image: vibrator for concrete

So, no one really knows where to get one. Is that what you are saying?

ThaiWatsudo, DoHome and HardwearHouse all have them. Other places as well.

[Thian]

Moats are great! You'll get loads of frogs/toads who sing at night, snakes who go after them, birds who come to drink/swim/poop.

Why not follow the thai and use the termite control systems with pipes under the concrete slab?

[David B in Thailand]

In Buriram it was simple for me to have Sika Plastocrete 901 Water Reducing and Retarding Concrete Admixture mixed with Siam City Cement at a local Ready Mixed delivery company. How clean the 3/4" stones were and specifics with the sand also were made clear to me by Mr. Khatayut Montatipkul . I was able to speak with Shiva Singh the Siam City Cement Technical Support Engineer for Northeast Thailand in English in person when I placed my concrete delivery order.  Slump cone on the ready mixed delivery truck and each load slump tested is readily available in Buriram. The better brands such as CPAC and Siam City Cement will have dealers who can offer slump test for your Thailand home building ready mixed concrete delivery. I was offered a test for compressive strength carried out either in a cube or cylinder in Buriram. Someone could explain the prices in English for the various concrete KSC and admixture in the ready mixed concrete  order. 

Edited September 9, 2017 by David B in Thailand

[Pacificperson]

Sheryl,

 

I can verify the validity of your moat. I used to run a tropical agricultural research station. When two of our very competent entomologists build a screen house to do controlled experiments, they built a small moat around it. It worked for them.

[r136dg]

On 2/5/2016 at 6:15 PM, maderaroja said:

Can someone please tell me how to get the Xypex into the concrete when the truck arrives?

You can mix whatever you want in the redi-mix truck on site. Trow it in the drum & tell the driver to spin (high rpm) the he!! out of it for several minutes. That's what we always did with biodegradable bags of fiber mesh & color. If more than one truck's needed make sure your ?/cubic meter of crete remain the same.

You're in Chiang Mai so I'd recommend Montree for the vibrator. They have a rack of vibrators & anything else you may need at decent prices. If they don't have it they can order it. It was a great find for me;-) Try finding hydraulic pumps here;-( 

Montree waterpump  107 & Hwy 11  053-212-311

[VocalNeal]

On 1/30/2016 at 11:57 AM, jacksam said:

Agree fully. What a crazy idea. Also how do you intend to enter your home. Jump? There exist much better methods. Also what your suggesting may in future become illegal with a dengue fever bill.

I know a guy with a "moat" full of gold carp. It is about 80-ish cm wide and about 1m deep. There is a bridge to cross to get near the house. It is only on two sides. He has a very tall dog. When the pedestrian door to the compound is opened with the dog standing on the bridge, one is staring the dog in the eyes