Re: Waterproofing a cement roofdeck

hope you buy in two colors.. so that you can visually see if you have evenly applied the rubberize waterproofing..

Re: Waterproofing a cement roofdeck

After waterproofing conduct at least 24 hrs flood test. Cover all floor drains and put enough water to cover the whole area.

Re: Waterproofing a cement roofdeck

@rpga4433: un nga, i forgot to get two colors. 🙂 just need to look closely nalang.

@bryant77: this is for an existing roofdeck without leak so this is more of a preventive measure.

problem is, may low pressure here so cant start. its raining hard today 🙁

Re: Waterproofing a cement roofdeck

Okey, finally done. Just to document this project:

Background: House was built in 2008, had the roofdeck built to standard (up & down with additional top and bottom grade 60 reinforcing bars), slab & beam poured simultaneously and I vibrated them personally. Area is about 110sqm with no slope, though there is a 1 meter opening on one side for water to get out. No finishing made on the concrete thereafter and was just exposed to weather. After 5 years, there was a sign of deterioration on the concrete. The ceiling had slight discoloration, particularly in areas where water pools. Planned to waterproof but waited for 2+ years for availability of budget and manpower. 🙂

After looking at various materials in the market, decided to choose campbridge primer + rubbercoat + watershield. Andrew (who is a member here) was very helpful and patient in all my inquiries.

After cleaning/brushing the roofdeck with water + muriatic solution, we applied the primer/sealer. Concrete was looking good after primed & sealed. It is applied white & dries clear.

After about 2 hours, we applied the rubbercoat. Had the first coat at 5pm, second coat at 8pm. Since the temp is colder, we decided to postpone the next coat the next day as drying took longer than expected.

It is indeed very "rubbery" and after covering the whole deck with it, the place looks like snow, very painful to the eyes unless youre wearing sunglasses.

We did 3 coats and made sure that the edges are really sealed (4 coats on the edges I think)

Re: Waterproofing a cement roofdeck

Had 2 masons and 5 helpers that day and while I would have wanted to do the concrete topping the next day, they were eager even though it would have to start at 1pm (due to the 3rd rubbercoat coating applied in the morning).
The masons estimated that we would finish just after sundown but in reality, only about 20% was done at sundown. haha

Had a 1:2 concrete:fine sand mix + 2 bags (200g each bag) of watershield admixture per mix. I initially planned for "Sahara" but after reading some dissatisfied users, decided to try on this integral waterproofer from campbridge. The masons can really feel the difference of this product

Finally done at 630 am the next day. We were up the whole night. I served them Cobra Energy Drink, Coffee and Red horse. hahaha

Curing concrete after my 3-hour sleep in the morning. 🙂

Re: Waterproofing a cement roofdeck

How did you treat the drains?

WHen I did my decks, one mistake we made was that we did not overlap the waterproofing on the drainpipes. You may need to aggressively apply that rubbercoat on the joint between the deck and the drainpipe,

Re: Waterproofing a cement roofdeck

No, there were no drains. There was about 2 feet that is not walled so water just exits there (adjacent to the stairs). I may have to apply rubbercoat on the wall because the paint peeled off already due to the water and dirt passing.

Re: Waterproofing a cement roofdeck

Had 2 masons and 5 helpers that day and while I would have wanted to do the concrete topping the next day, they were eager even though it would have to start at 1pm (due to the 3rd rubbercoat coating applied in the morning).
The masons estimated that we would finish just after sundown but in reality, only about 20% was done at sundown. haha

Had a 1:2 concrete:fine sand mix + 2 bags (200g each bag) of watershield admixture per mix. I initially planned for "Sahara" but after reading some dissatisfied users, decided to try on this integral waterproofer from campbridge. The masons can really feel the difference of this product

Finally done at 630 am the next day. We were up the whole night. I served them Cobra Energy Drink, Coffee and Red horse. hahaha

Hi there koykoy,

Thanks for sharing your documentation of the said project, this is very enlightening and informative specially for those who might also be thinking or planning on waterproofing a concrete roof deck.

I am just curious on the last step that was done, wouldn't the concrete mix topping crack in the long run since basing on the pics posted, it is not that thick enough or maybe was there some solution, treatment or something that was added to the concrete mixture to keep it from cracking. Just asking bro for additional information. 😉

Thanks !

Re: Waterproofing a cement roofdeck

HI rosy, thats what I was thinking too, if the concrete cracks, given that its thin and the substrate that it adhered is rubber. I guess, only time will tell. Anyway, its main purpose is to protect the rubbercoat underneath for foot traffic.

I guess if they unbond, then it will be the whole, just like tiles, especially if the slab is flexy. Anyway, if this happens, then redo the concrete topping, probably with 3 inch concrete with 9mm reinforcing bars at 60cm. 🙂 Though hopefully not because it would mean a lot of work and budget involved.

Re: Waterproofing a cement roofdeck

Hello gentlemen, thanks God I found this informative site.

I just need your expertise about waterproofing. I am planning to cover a ceramic tiles for my concrete roof deck. What are the best product and the type of waterproofing to be used. Any suggestions and guidelines?

thanks a lot

The big problem about waterproofing is movement of the surface on which it is applied. Some of the hard waterproofing products like cement based products will crack if the concrete on which it is applied cracks. Then leaks start again.

Cracks occur more regularly where a roof deck meets a wall. In instances where movement is expected, the best waterproofing will be those that are flexible. Some elastomeric paints are guaranteed to be flexible.

For really tough jobs, I suggest for your friend to bite the bullet and invest in hot applied rubber or asphalt type waterproofing. The sheets are fused together and to the roof surface with heat. And the asphalt will be flexible enough over the cracks.

There are many suppliers of this type of waterproofing as it is not really a DIY operation. But ask your friend to get referrals and guarantees.

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Re: Waterproofing a cement roofdeck

I am in favour of using the hot applied type of waterproofing (membrane), but would it be good for having a ceramic tiles on top of it?

I need your suggestion and advice

Appreciated much of your response
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Re: Waterproofing a cement roofdeck

try Drylok..expensive it is...but sure it gets the job done right the first time...

I am just not sure for its use over ceramic tiles.

V

Re: Waterproofing a cement roofdeck

What are other options aside from using a membrane (hot applied). I was thinking it would cost me double/triple, considering another layer of tiles on top of it.

I received a quotation from a guy who work in the hardware.
membrane 3,500/roll = 12rolls will be used
bituminous primer 4,946/pail = 2 pails will be used

floor area = 95 sqm.

total mat. = 51,000 something
total labor = 23,000 something

when I had this total, I was thinking twice... I should go for a license company that will work on it. Any of you guys know where to ask for the job somewhere in Cebu city? maybe I could get a performance w/ a good price as well.

thank you

Re: Waterproofing a cement roofdeck

Has anyone tried Campbridge Rubber Coat?
http://www.campbridge.com/RubberCoat%20Technical%20Info.html

Application seems straightforward and can be DIYed.