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sparks

Jun 22, 2011, 7:43 AM

Post #1 of 13 (3333 views)

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The rain and my new roof

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First rain of the season and I now know the roof leaks. Same places it was leaking before we put on the Tacata layer.

Guess this means I get a power washer, wait for a dry spell and roll on impermeabilizante - probably Fester. Fester was quoted at about 1200 a cubeta. A cubeta will do about 20 meters in 2 coats. My roof is about 110 sq meters

Sparks Mexico - Sparks Costalegre

rockydog85251

Jun 22, 2011, 8:39 AM

Post #2 of 13 (3312 views)

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Re: [sparks] The rain and my new roof

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We did a torch down roof in Mazatlan & it was guaranteed for appx 15 yrs. This was about 5 yrs ago & it has held up very well, no maintanence required so far. It was a bit more expensive but we felt it was worth not having to worry about it every year or so. Not sure if it might be available in your area.
Willie

sparks

Jul 6, 2011, 5:40 AM

Post #3 of 13 (3182 views)

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Re: [rockydog85251] The rain and my new roof

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Just found there is a guy that does hot tar roofs here .... but was advised by an architect that it's really hard to remove if you plan second story construction. Don't have any prices yet.

Sparks Mexico - Sparks Costalegre

whynotwrite

Jul 15, 2011, 1:05 PM

Post #4 of 13 (3061 views)

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Re: [sparks] The rain and my new roof

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First off you must find the source of the leak. Sometimes there is a bit of trial and error but not knowing where the problem is could cost you thousands of pesos. Find the leak area on the ceiling and go up from there, it never leaks up, it always leaks down.

sparks

Jul 15, 2011, 4:19 PM

Post #5 of 13 (3041 views)

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Re: [whynotwrite] The rain and my new roof

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Found that the hot tar roof is about twice what the standard roof seal is including the cloth material and using Fester impermeabilizante ... but it may be a 30 year roof rather than 3-5

I have a new roof that leaks almost everywhere .... and I believe water will travel in cement somewhat like wood construction. Also have a one meter wall around the roof that is not stuccoed and sealed. Possibly seeping down from the porous block? Will be having the stuccoing done next week. Now I'm cleaning the roof and filling low spots. After roof walls are sealed and painted I'll use 3-4 coats of impermeabilizante and material

Sparks Mexico - Sparks Costalegre

whynotwrite

Jul 15, 2011, 5:25 PM

Post #6 of 13 (3027 views)

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Re: [sparks] The rain and my new roof

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That block is like a sponge , if it is not covered it will leak to high heaven. That is where the problem probably is happening.
The roof seems like it is leaking every where but it tends to follow where the conduit is laid in the roofing (cement). from the highest point in the ceiling ( where it drips) on upward is where the problem lies, further down is unlikely the problem is anywhere in the ceiling.
hairline cracks in the roofing cement usually are not the problem and are common, they should be sealed but in reality not much water enters by them.

johninajijic

Jul 16, 2011, 3:24 PM

Post #7 of 13 (2995 views)

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Re: [sparks] The rain and my new roof

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I have had a lot of experience learning from an expert contractor who has 26 years experience here in Ajijic. You MUST wait for dry weather before doing your roof (after October) otherwise your results won't be good and you'll have wasted tons of money on material. Here is a copy and paste of the PROPER way to do the roof. Use the best 10 year Fester with Fibers in it for strength along with Membrane. It is about $ 1,800 pesos a cubeta. Get a high quality contractor to do it who will give you a 10 year guarantee.

ROOF SPECIFICATIONS

Here is what you need to ask your Contractors so they bid apples to apples and you will get a good job.
November thru May is the best weather for roof work. Weather and surfaces MUST be dry.

1. Scrape, grind all loose material and rough areas. Acid wash the roof. Clean using a power washer, otherwise
Fester Acriton will not adhere.

2. Check all loose roof tiles. Remove loose roof tiles, inspect for cracks, repair and recement roof tiles.

3. IMPORTANT: Put a very thin concrete only cement wash over the roof tiles, otherwise the Fester Acriton will not bond.

4. Apply Fester Festerbond to roof. (This is a high quality bonding agent)

5. Apply a thinned down coat of Fester Acriton to roof. Lay Membrane into this Fester Acriton. Put on another
coat of Fester Acriton.

6. Apply 5 more coats of Fester Acriton as it comes from the bucket, without thinning, on the roof on different days, allowing each coat to dry.

7. Your Contractor should give you at least a 7 year Guarantee and better yet a 10 year Guarantee.
You should check his references and talk to others he has done roofs for.

(This post was edited by johninajijic on Jul 16, 2011, 3:33 PM)

whynotwrite

Jul 16, 2011, 5:22 PM

Post #8 of 13 (2980 views)

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Re: [johninajijic] The rain and my new roof

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sounds like we can´t build that rocket until Oct. ... then we can get bids ( they do that there??) or should we call it a quote. Then we can also get bids to repaint the entire inside of the house. Heck, its pesos, not real money.
This needs to be fixed now, not after the rain has passed. Whats the point of having a leak proof roof when there is no rain, ..wait until Oct.? I have 9 buildings with cement roofs, it is not rocket science. Find where the leak enters the building, fix the leak, end of story.

johninajijic

Jul 16, 2011, 5:25 PM

Post #9 of 13 (2980 views)

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Re: [whynotwrite] The rain and my new roof

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Fix your leaks, then wait until at least October to apply Fester Acriton.

Sculptari

Jul 17, 2011, 7:30 AM

Post #10 of 13 (2948 views)

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Re: [whynotwrite] The rain and my new roof

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We are having some major leak problems here in Puerto Vallarta. Huge planters were installed along the perimeter of our roof, used as a deck by a neighboring condo development. After many years, and recent heavy rains, the problem has been isolated as the planters leaking into the concrete roof. This year, they finally installed drains in the planters, and brushed on Fester goop, but the pressure was too much, and has been left for too many years. The underlying roof is like swiss cheese, weak and crumbling concrete. The planters now have to be removed, and the concrete has to be replaced with WATERPROOF concrete and possibly some fresh rebar. Leaks are real hard on rebar, they eventually swell to many times their original size and burst the concrete.

http://www.kryton.com/
I know this is available in Mexico, and I know it really works.

As far as the weather, fresh concrete should be protected from direct rain, but it also is properly wet cured for a week, heat doesn't matter, in fact steam is the best way to cure concrete. Black plastic is ideal.

chicois8

Jul 17, 2011, 1:45 PM

Post #11 of 13 (2915 views)

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Re: [Sculptari] The rain and my new roof

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" Leaks are real hard on rebar, they eventually swell to many times their original size and burst the concrete."

And if beach sand (salt) was used in the concrete mix it would be bad for rebar and cement strength...

Sculptari

Jul 17, 2011, 2:01 PM

Post #12 of 13 (2910 views)

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Re: [chicois8] The rain and my new roof

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I was discussing this with a Mexican mason just the other day. We agreed that it was not so much the salt of river and beach sand, that is easy to rinse out, it is a problem that the sand is rounded over - it is not 'sharp' as we call it. The sharpest sand is the silica sand they use for sandblasting - it is incredibly strong once it locks together. Portland cement is actually very weak, I don't know the metric conversion, but it's compressive strength is something like 2,000 psi. It is the aggregates which provide the endurance.

sparks

Jul 17, 2011, 3:43 PM

Post #13 of 13 (2901 views)

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Re: [johninajijic] The rain and my new roof

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I think I've decided doing the cement wash of a 110 meter roof all the same day was moving too fast ... at least for my guys that don't do it often. Lots of little air bubbles, tortoise shell cracks and more broom marks than necessary.

I carefully started a second wash today and as long as you keep it damp for several hours it gives a nice surface. Just need to speed the process a bit from paint brush to broom.

Direct rain .... I used a garden sprayer to keep it damp. This may be a summer long project

Sparks Mexico - Sparks Costalegre