Waterproofing flat concrete roof

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ashtondav
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Waterproofing flat concrete roof

Postby ashtondav » Fri May 06, 2016 4:18 pm

The casita that holds my wood pile has a flat concrete roof that leaks. I am In the UK at he moment and like the look of BOSTIK FLEXACRYL GREY INSTANT ROOF REPAIR.i have used before with great success .Can you obtain this in Spain and where? If not is there an alternative?

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country boy
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Re: Waterproofing flat concrete roof

Postby country boy » Fri May 06, 2016 6:54 pm

The best product, by far, down here is Caucho con Fibre. Several colors, and available at good Ferreterias and all builders merchants. I am totally impressed by it's durability and covering power.

MartinEB
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Re: Waterproofing flat concrete roof

Postby MartinEB » Sat May 07, 2016 7:34 am

a flat roof has been the bane of my life here. Our casita roof was the traditional wooden beam, bamboo, plastic membrane with Launa (not too sure of the spelling, but the clay like dirt that is placed on top)?

This leaked like hell and I paid to have it replaced with a new waterproof membrane, sealed up the edges of the wall and then covered with gravel. This worked for a while, but then also started leaking! I tried patching it up with sikaflex sealant, but the leaks just kept shifting!

My Spanish neighbour then suggested I might use the bitumen waterproof membrane, the type you seal the joints together with a heat gun and then seal up the wall slightly with a heatgun also to make it watertight. He helped me do it. We removed all the gravel down to the plastic mebrane, put the new bitumen waterproof membrane on top and it has been brilliant ever since - not a leak in sight. cost about 47€ a roll and I needed 3 rolls for a casita about 5m². Comes in a variety of colours, not too sure what it's called but available at most building supplies.

Image

Maybe a bit more than it sounds like you need on your roof though :think:

TorreDelAguila
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Re: Waterproofing flat concrete roof

Postby TorreDelAguila » Sat May 07, 2016 1:03 pm

Another vote for caucho - a kind of thick rubberised emulsion paint, which can be brushed, poured or rollered to give a flexible 'rubber' layer up to 5mm thick (although 2-3mm is good enough for most purposes).

Several cheap and useless brands around.
Best is TKrom's 'Antigotteras', available in white, terracotta (rojo), blue or green. Fabulous stuff.
Available from Pinturas Andalucia, and elsewhere.

Apply to any clean surface. Can be cemented/tiled over, acting as a waterproof membrane underneath.
Can also be left as a top-coat, and is sun-proof.

In white, makes an excellent non-slip pool surround paint, capable of being turbo jetwashed.
Chris

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Re: Waterproofing flat concrete roof

Postby El Cid » Sat May 07, 2016 3:27 pm

When I had my roof done, they used fiberglass matt soaked in caucho. I guess Country Boy's suggestion of using the one with fibre in it is similar.

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Re: Waterproofing flat concrete roof

Postby truebrit » Sat May 07, 2016 4:40 pm

Definately Caucho, just did ours 3 months ago, perfecto

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gerryh
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Re: Waterproofing flat concrete roof

Postby gerryh » Sat May 07, 2016 4:52 pm

Another vote for Caucho.
Did one of my terraces which forms the roof of a storage area below.
Thought it would only be a temporary fix but still waterproof after 3 years.
Cheers
Gerry
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ashtondav
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Re: Waterproofing flat concrete roof

Postby ashtondav » Sun May 08, 2016 9:52 am

Is it available in leroy merlin?
And thanks for the help

Gasman
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Re: Waterproofing flat concrete roof

Postby Gasman » Tue May 10, 2016 2:56 pm

You will probably find that it is actually cheaper in your local ferreteria!!

TorreDelAguila
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Re: Waterproofing flat concrete roof

Postby TorreDelAguila » Tue May 10, 2016 5:03 pm

Do not buy the cheapest. Some of these actually dissolve in subsequent rainwater - and I speak from experience.
That is why I recommended TKrom's Antigotteras.
Others may recommend brands they know work well.
Do not buy this stuff blind: patching up afterwards may not be possible.
Chris

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spanish_lad
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Re: Waterproofing flat concrete roof

Postby spanish_lad » Thu May 26, 2016 3:45 pm

caucho is what everyone uses - look around from the roof terrace, its normally red, and i recomend a roller on a pole. and dont paint yourself into a corner... :lolno: and go up the sides about 10 cm. and do two coats, a week apart. and dont do it when its been raining.

if thats the way the spanish do it, that must be the cheapest / most cost effective.
Alhaurin el Grande since 99, working at the airport since 2011.

TorreDelAguila
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Re: Waterproofing flat concrete roof

Postby TorreDelAguila » Thu May 26, 2016 4:37 pm

Just to repeat, do not buy cheap caucho, though. You can regret it bigtime.
A can I still have here, and which is absolutely useless (dissolved in subsequent rain, leaks...), is Caucho Rojo, by Menape.
That's why I recommended TKrom's Antigotteras . . . it works.
There will be other good brands too, but it's down to personal testing, in the absence of comprehensible test data.
Chris

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Trooperman
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Re: Waterproofing flat concrete roof

Postby Trooperman » Thu May 26, 2016 8:31 pm

When I had my roof done, they used fiberglass matt (sic) soaked in caucho.
+1 on that....just seen a chap down the road do this same treatment...and he is a professional painter!
nil illegitimum carborundum

TorreDelAguila
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Re: Waterproofing flat concrete roof

Postby TorreDelAguila » Thu May 26, 2016 9:27 pm

Agree - the mat resists fracturing of the 'rubber' caucho layer, in the event of movement.
Chris


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