Whats the best waterproofer for a concrete slab?

[BratPAQ]

baka may expert sa waterproofing dito. its basically a concrete roof, and everytime pinagagawa namin eh may tulo pa rin sa loob. i remember nilagyan na sya ng carbon fiber sa ilalim ng palitada hen some waterproofing white paint, tumutulo pa rin. maybe because may crack na sya ngayon dahil gumalaw ang lupa. we also had the outside concrete wall painted with waterproofer, may pumapasok pa rin ng tubig.

right now ang balak ko eh flinkote waterproffing type 3, then patungan ng roofguard. any other suggestion? they said this combo might only last 5 years. which is ok for me since this roof has been a money pit for us.

[viper888]

Membrane sheet waterproofing and your topping should have a cementitous waterproofing admixture like sika 107. Also the roof should have a minor slope (2% is enough)


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[BratPAQ]

Membrane sheet waterproofing and your topping should have a cementitous waterproofing admixture like sika 107. Also the roof should have a minor slope (2% is enough)


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thanks for the suggestion. slope on the edge? or the whole roof? we also planning to add another floor and the slab would turn to floor eventually.

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[viper888]

thanks for the suggestion. slope on the edge? or the whole roof? we also planning to add another floor and the slab would turn to floor eventually.

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Slope on the whole roof towards the edges or drain (if there is), you can just add a topping later on to flatten it.

The cracks come from the natural expansion and compression of concrete.

More economical other option:

i would still recommend an admixture for the concrete topping but no need for the membrane waterproofing.

[n_spinner06]

Will be working on ours this week pag natuyo ang ulan. Will be applying the asphalt membrane diy. Did the waterproof paint a few years back and it obviously failed. Problem lang is originally may slope yun, pero ngayon nagkaroon ng depressions. Konting tulo lang naman and i dont want to add another layer of concrete just to correct the slope. Will this do?

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[viper888]

Will be working on ours this week pag natuyo ang ulan. Will be applying the asphalt membrane diy. Did the waterproof paint a few years back and it obviously failed. Problem lang is originally may slope yun, pero ngayon nagkaroon ng depressions. Konting tulo lang naman and i dont want to add another layer of concrete just to correct the slope. Will this do?

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I recommend you add topping to fill the depressions, water will just be stagnant there and eventually leak.

Yours is not an isolated case, many concrete slab roofs leak. Usually the topping cracks due to age. Concrete is actually very porous.

When someone wants a house with a flat roof, i would advise them that its more expensive. The additional cost of waterproofing is easily 3-4k per sq when done properly. Many like it so they have a party place on top and they can optimize a village's height limit.

[n_spinner06]

I recommend you add topping to fill the depressions, water will just be stagnant there and eventually leak.

Yours is not an isolated case, many concrete slab roofs leak. Usually the topping cracks due to age. Concrete is actually very porous.

When someone wants a house with a flat roof, i would advise them that its more expensive. The additional cost of waterproofing is easily 3-4k per sq when done properly. Many like it so they have a party place on top and they can optimize a village's height limit.

Yup considered adding a topping...actially ginawa na namin before we painted over it. The problem was manipis lang topping sa depressions natutuklap din after a while. Kung kakapalan naman, we will be forced to add whole layer to the whole area which is not cost effective very minimal lang naman kasi yung tulo. May stagnant pools pag maulan na up to around 5mm deep that i really couldnt get rid of. Once the sun comes up natutuyo naman agad. What do you think?

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[dr. d]

after years of suffering... the earlier "solutions" offering only temporary reprieve...
linagyan na lang namin ng roof.
the area involved is maliit lang naman.

yes, the initial guys probably did not know what they were doing, but it is not easy to look for guys who really know. i mean, everybody we talked to, said that they can do it. but as was subsequently proven, none did.

[viper888]

Yup considered adding a topping...actially ginawa na namin before we painted over it. The problem was manipis lang topping sa depressions natutuklap din after a while. Kung kakapalan naman, we will be forced to add whole layer to the whole area which is not cost effective very minimal lang naman kasi yung tulo. May stagnant pools pag maulan na up to around 5mm deep that i really couldnt get rid of. Once the sun comes up natutuyo naman agad. What do you think?

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If you dont cover the depressions, it will survive a light to medium rain but may leak in a week long season of heavy rain.You can also use skimcoat (get the 3-6mm) but you should still apply waterproofing. (Theoretical, never tried)

Optimally, the concrete slab should have an integral waterproofing mixture like Sika 1as part of the concrete mix if its to be used as a roof deck.

[BratPAQ]

Maganda ba yung ginawa ng biyenan ko sa bahay nila? Nilagyan ng palaman yero yung gitna ng concrete slab nila at makapal yung yero. Imbis na bakal.

Back at my home. We are planning to put another floor on that slab. At gumamit na lang ng yero as roof, nakakadala ang slab, I wished someone warned us back then when we are still planning it. But we don't have a budget yet for it since kailangan din ng budget sa pader.

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[n_spinner06]

If you dont cover the depressions, it will survive a light to medium rain but may leak in a week long season of heavy rain.You can also use skimcoat (get the 3-6mm) but you should still apply waterproofing. (Theoretical, never tried)

Optimally, the concrete slab should have an integral waterproofing mixture like Sika 1as part of the concrete mix if its to be used as a roof deck.

Noted, thanks! We need a quick fix at the moment so this will do. We will consider something more robust for the long term. Thanks again!😀

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[NightRock]

Simple lang ginawa ko sakin after ng manipis na layer ng cement nilagyan ko ng plastic sheet yung na bibili sa divisoria na mga naka rolyo. then saka pinatungan ng semento at sahara, then tiles. ayos walang tulo ever since

[CVT]

Am using membrane and topcoat on our 12m x 6m balcony. Kind of touchy because it is also the roof of a portion of our garage. Cannot afford a leak.

We did a three day swimming pool test during construction...

So far, no visible issue after over a decade....

[pyramid00]

Simple lang ginawa ko sakin after ng manipis na layer ng cement nilagyan ko ng plastic sheet yung na bibili sa divisoria na mga naka rolyo. then saka pinatungan ng semento at sahara, then tiles. ayos walang tulo ever since

our flat cement roof is over 10 yo. Pag may visible cracks, we just apply a coating of tar over it. Do not use tar if the cement is wet. If completely dry, a tar coating will provide months of water protection.

[n_spinner06]

our flat cement roof is over 10 yo. Pag may visible cracks, we just apply a coating of tar over it. Do not use tar if the cement is wet. If completely dry, a tar coating will provide months of water protection.

Where do you source your tar sir?


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[dr. d]

our flat cement roof is over 10 yo. Pag may visible cracks, we just apply a coating of tar over it. Do not use tar if the cement is wet. If completely dry, a tar coating will provide months of water protection.

i agree. months only. our cement roof leaks every other year.. no leak on year one, because tar is newly applied. it leaks on year two...
truly!
heh heh.