Stubborn leaks in a concrete roof

Old 10-12-09, 11:59 PM
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Question Stubborn leaks in a concrete roof

Hey guys, I just moved into a flat at the top of a concrete block...

The roof is full of cracks and water leaksin drops into my kitchen and al along a wall.
I did:
- cleaned the surface from the former roof coating - now completely deteriorated
- filled all visible cracks with hot tar
- covered all with 2 layers of Hydrostop Atlas - a rubber membrane which has to be dissolved in water but when it gets dry, becomes rubbery-they say...
Now the fall rains begun and my roof leaks AT THE SAME points !

what to do ? I read about some other membranes,but i dotn really trust anything anymore, plus I dont know how this will get stick to this layer of hydrostop...

oh, and.... well, I'm not so wealthy to afford a team, a specialized company, I have to do it myself...

thank you guys for your time
Old 10-13-09, 08:34 AM
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Has anyone checked the roof drains to be sure that they are clear?
Old 10-13-09, 10:41 AM
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Stubborn leaks in a concrete roof

paphet -

It has been my experience that many leaks on concrete roofs really occur at the edges. Depending on how you edges are built and detailed, there could be a flashing the goes down the wall face (usually not far enough because wind can drive rain upward a long distance) or at some sort of raised edge or parapet wall where water can enter and show up inside, no matter how good the roof surface is. Water will travel long distances horizontally and then leak downward to a place where it can leak downward and appear on the interior surface.

I have been in Romania several times, but really aware of the roof construction and details. the weather was also good every time I was there, so I am not aware of the types of rain storms you may have.

Is this one of the 100,000+ flats that was vacant for years around the end of reign of the infamous dictator and that remained empty for a few years after they removed him?

Bucharest was a great city in the 1920's and 1930's but suffered later despite the construction of many magnificent buildings that were really monuments and really used. I think it is still magnificent and fascinating.

I had some friends in Suceava and spent time there and enjoyed the wine from there and Moldova.
Old 10-14-09, 01:36 AM
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yeah, I guess it is fine, although it seemed to me that its 2" diameter is too small - for a 80 squared meters roof. But I'm not an specialist.


Nice to hear you know so much about Romania - and good impressions, too

The block I live in was built in 70s, just as the rest of them all over the country (a trend in all comunist countries) - they all are inhabited alright.

The main issue is not the storm but about snow in winters (I live in a town in the mountains) - gets to 10" as mean value.
I guess you're right about the mechanism of flashing since we do have parapet walls, and i saw a longitudinal creekon one side.- which i filled up with that "wonder" solution...

Anyway I dont thing I can do much right now - keeps raining since the day before yesterday -even snowing here and there.

But iI thought to put that synthetic rubber membrane - although expensive - called Firestone, you guys must know it since it's an American manufacturer.

My real concern now is if I can put it on on a wet roof and on temperatures which at night can get to minus a few Celsius ? I read the technical booklet but they dont specify anything about these 2 conditions wet roof and negative temp.

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