Re: Waterproofing a cement roofdeck

Re-asking in this thread as there may be new suggestions.

I have a 4 decks/balconies in my house, all with Mariwasa tiles and all, after 7 years are leaking. Didn't know whit about waterproofing when my house was built so can't tell you what the contractor used but I recall he painted something reddish that he says ends up rubbery, then topped with tiles the normal way.

Initial problems we had were leaks where the drains are. We had to dig out the drains covers, reapply this magic reddish goo, then reinstall the covers.

Next summer, we plan to tear out all the tiles and apply waterrpoofing since our ceilings have ugly water spots already. This is a costly and grossly inconvenient activity so would appreciate advice on how to do this for good.

let me quote you from another thread:

Sorry, let me correct myself. I get fiberglass cloth from Polymer; I have friends who buy their epoxy resins (for boatbuilding).

They sell resins in two parts by the gallon. Each gallon is about P1.5k+. Ratio of mixing is 1:2. But epoxy resins shrink. That's why we pour them proud when filling gaps or holes (e.g. making bushings).

In another message, you mentioned polyurethane as deck waterproofing. Why not epoxy? (question, not a suggestion).

You are right that this should be in another thread. There is one here. Do you mind posting your suggestion re waterproofing in that thread?

I have a lot of tiled decks in my house and many are leaking. I will probaly have them torn off next summer and put waterproofing. Since this is a costly and grossly inconvenient exercise, I'd like to do it right and for good. Thanks.

the suggestion to remove your existing tile grout and re-grout is a good one. specially if only a couple of tiles are loose. then you can seal the new tile grout with clear acrylic sealer as added protection.

also don't forget to completely waterproof you roof deck walls (parapet).

the reason why epoxy is not recommended for roof deck waterproofing is because it yellows and possible to chalk under direct sunlight. aliphatic polyurethane has excellent UV or direct sunlight resistance.

let me suggest as early as now, you can ask several waterproofing contractors (get referrals from younger engineers and architects you don't know) to take a look and submit quotations. ask each of them to quote at least 2 different waterproofing systems plus applied samples and technical data sheets of the product they intend to use.
their visits and quotations are free.
don't forget to ask for their projects references. your best bet would be a company that has been around for more than 10-15years and have done several big waterproofing projects.

then come summer time, choose the best waterproofing system you can afford and ask for the longest warranty - say 10years.

Re: Waterproofing a cement roofdeck

you may want to check out polyurethane waterproofing:

http://www.philpu.phpnet.us/

thanks!

Re: Waterproofing a cement roofdeck

Thanks. I'm familiar with epoxy on wood (and pu) but not sure about application on concrete sandwiched between tiles. I'm aware that epoxy is used in repairing pavement cracks but not sure if the epoxy resin I use (on boatbuilding) is the same.

Also, epoxy is very expensive. And, not sure how concrete would absorb it. If concrete sucks it like a sponge, it'll cost quite a bit.

On PU waterproofing, I'd use it only on areas not fully exposed, since, from my experience, they do wear out after a few years. I'd prefer epoxy as primary waterproofing then PU was UV protection.

Will take your suggestion on asking contractors and references.

Re: Waterproofing a cement roofdeck

@bala
could it be that the leak's in the fittings of the downspout? i've had that problem.
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Re: Waterproofing a cement roofdeck

torch membrane is a good waterproofing material

http://philpu.phpnet.us/notorch.htm

but i recommend something seamless

Re: Waterproofing a cement roofdeck

must be concrete roofdeck not cement

Re: Waterproofing a cement roofdeck

katatapos ko lang last month yung aking concrete roofdeck, since magaspang ang finishing ng roof deck at siempre bago aplayan ng Flexibond - Boysen Product na recommend ng isa ko katrabaho, May gumawa na po ba dito na lagyan ng tiles as final layer (with mortar).

Anu epekto nito sa flexibond? Thank you in advance.

Re: Waterproofing a cement roofdeck

Me i've tried "Powermix" and a similar product, "AllWeather Concrete Bond". I've tried them both in roofdecks in separate occasions and they performed well. Hanggang ngayon wala pa rin tagas. They are mixed with cement at certain ratios. I've noticed one time may leftovers na napadikit sa plastic cover nila at natuyo, nun pi-neel-off ko sila, I've noticed the film (a mixture of cement and the liquid) is really tough and flexible, parang elastomeric sheet.

This might be a good alternative to membrane based waterproofing. My roofdeck is unfinished and so far no leaks yet after 5 years (knock on wood). Maybe after the rainy season, i'll have it finished with this concrete mix (maybe 2cm thick) then have it painted by flexseal as suggested below:

For a 50 sq.m. roof deck, you may need around 18 gallons of FlexSeal. Buy two colors like black and terra cotta so that you would know if you totally covered previous coating. Give an interval of 4 hours drying time (8 hours is best).

What we usually do for our project is this system:

1. Coat all area with FlexSeal Terra Cotta.
2. Then with FlexSeal Black.
3. While the coating is still wet, lay a sheet of polyester reinforcing mat - then coat with Flexseal Terra Cotta.
4. 4th coat - Black, 5th coat - Terra Cotta, 6th coat - Black.
5. And finally 7th coat FlexSeal Terra Cotta - and while the coating is still wet - introduce fine grain sand on the surface - the reason is that the sand will increase bonding with your concrete topping later.
6. Allow a few days to let the waterproofing dry completely, then flood test it.

Hope that helps.

If you have more question, dont hesitate to call Campbridge at 252-0531. Or email me [email protected].

Peace 🙂

p.s. the material cost will be around P 8,550.

What do you think mga sirs?

Re: Waterproofing a cement roofdeck

Suggestions/experiences by these two members sounds fine with me, I cannot say its the ultimate solution but with their testimonials, its worth giving a shot !!! 😉 :sun: 😎

Re: Waterproofing a cement roofdeck

Just to let you all know what I did to my deck.

After evaluating the recommended "overhaul" solutions, wife and I decided to take a chance at some white gooey liquid (will post the name when I recall) on only the grouting of the tiles on my deck, of course, overlapping a bit into the tiles.

Rationale is that the tiles are waterproof but the grouting may not be. We do not think this will be long-lasting but, even if we re-apply every year, it will still cost a heck of a lot less than a polyurethane solution over several years (or my lifetime). We also repainted the parapet walls with elastomeric paint.

This was completed around Christmas.

There has been a number of rather strong downpours since then. No leaks.

Re: Waterproofing a cement roofdeck

hello all, i'm a returning member and i'm in need of this roof deck waterproofing as well. my roof deck is around 70 sqm and has already cured (more than 30 days now) and i'm also looking into campbridge's waterproofing solutions. recommendation was to use greenseal but this is a bit expensive compared to a 7 coat of their flexseal elastomeric paint. i would like to consider the 7 coat but would it be more economical to use their acrybond as the 1st & 2nd coating then probably two coats of flexseal elastomeric paint on top of acrybond. price of acrybond is almost similar to the elastomeric paint...what do you think guys?

Re: Waterproofing a cement roofdeck

reading this thread for years now and still i havent waterproofed my concrete roof. hehe

i read of a new product from cambridge: it is rubber. thoughts?

http://www.campbridge.com/RubberCoat%20Technical%20Info.html

Re: Waterproofing a cement roofdeck

reading this thread for years now and still i havent waterproofed my concrete roof. hehe

i read of a new product from cambridge: it is rubber. thoughts?

http://www.campbridge.com/RubberCoat%20Technical%20Info.html

Well, thanks for sharing the link of Cambridge with their new product of water proofing, this may surely be very useful for most homeowners wanting to waterproof their roof decks or other roofing system for that matter.

;):thanks:

Re: Waterproofing a cement roofdeck

Just got this morning. Looks like a lot of work this weekend. Will try to document this project for others to check & see. 🙂

Re: Waterproofing a cement roofdeck

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