Concrete Roofs: Uncontrollable Leaks!

I sopke recently with a roofing contractor that installs roofing for situations like yours. They are required to provide lengthy warantees on these roofs. His recommendations for the roof we needed to replace were the same as the one Del made.

(1) How did the contractor explain why EPDM was better than other polymers?

(2) Is your roof flat? Did you consider than the original requestor's problem might be BUR (a roof system for flat roofs) or, for really poor areas like Puerto Rico, tar paper without the normal 3 tabs used over tar paper in the USA?

(3) What type of attachment system was recommended for EPDM by your contractor? Could I get an electronic explanation of the attachment technology?

(1) Requester should remember the economics of EPDM rubber. One aspect: Should EPDM include biocides, if legal (kills moss; mold; discoloring growth; growth that eats rubber). Even if the roof material has no increased service life due to the biocide, decreased labor costs to maintain appearances may warrant investigating biocides. Biocides in the EPDM are likely to be cheaper and safer than applying biocides on top of the EPDM after installation.

(2) The temperature range and direct sun is easily handled by EPDM. Thus, there may or may not be a financial value to consider white-painted EPDM; compounded-white EPDM; or the normal black EPDM. White reflects sunlight, so the roof does not get as hot when white (versus black).

(3) Other possibilities for barely flat (1 foot verticle rise for 12 foot horizontal, or steeper) roofs: Neoprene rubber, PVC, Hypalon rubber, torchdown, metal?

(4) Consider the immmense value of a meaningful, long warranty (20 years??). This means a warranty isssued by the material manufacturer. Installing companies "come and go".

(5) "Google" to learn how to do an economic analysis of roof materials. Learn if there are meaningful certifications for installers in your area.

PS, I have a 15,000 s.f. leaky, old roof. I heard (rumor) that BUR was superior 30 years ago compared to BUR today because: (a) poorer work ethic. (b) Oil companies extract more "good stuff" from BUR compared to 30 years ago.

1st and 2nd floors are flat. Seriously considering another roof.

Angled of course!

Thanks!

Good answer.

Would a Polyurethane work? A neighbor suggested this in addition to your suggestions?!

spray foam w/ silver over Andek co. in N.J. for great coatings

What is the material brand name or cost?

Polyurethane will see you through one rainy season. Mark on your diary in end of October pages:
"Polyurethane recoat time"!!

The rubber sheet has lasted for 10 years so far. Limited walking on it has occured but is not encouraged. You could layer over it with somthing like indoor/outdoor carpet to allow some walking but the danger would be that any small particle say a stray toothpick could get underneath the carpet and cause a puncture with the traffic.

Roofing products sold commercially are expected to last many years. The warranty on some of these products is 20 years.

1. Urethane paint has no inherent problem.

2. Was you observation based on urethane rubber of the polyester or polyether type?

3. Can you document your comment? Perhaps your problem was poor workmanship and not inherently flawed material technology.

Urethanes are GREAT in abrasion resistant, which is valuable if heavy daily walking on the roof is a concern. EPDM is good in abrasion resistance (enough for one person walking per day on a route; perhaps ok if one person skates on a route), and EPDM is much less expensive.

Summary: Only the decorative potential or abrasion resistance of urethanes make them worth considering, due to expense. For my roof, I won't even think of PU unless a contractor urges me to.

I built a dome roof house with lightweight masonry, applied EPDM sheet and then painted with white elastomeric paint. Makes a nice roof and should last at least 30 years before another coat of paint.

Yup...you and me are the only sane ones....

EPDM will cope with large movements , where other systems will crack, slump,wear...fail.

Del

1. For the roof of my building that was just built, I used 2" x 12" beams with tar paper under 3 tab shingles on a 5/12 slope roof. What is the advantage of masonry material on a dome roof? Can I get a technical description and brand name of the masonry and the dome dimensions?

2. Unless the white paint is based on rubber, the paint won't last more than 10 years, I'd guess. Was the paint primarily a precaution, or did you do an cost-benefit guess? EPDM should last "forever" with respect to heat and light in USA ranges. Painting to reduce aging is not what I would expect. UV light or roof temperatures are far too mild for EPDM.

SIMPLE GO TO A BUILDING SUPPLY/PAINT STORE GET A GALLON OF AIRBOL

THAT IS BASICLY PAINT WITH LIQUIDRUBBER CUT THE FIRST COAT BY 15%

THEN APPLY FOUR MORE COATS GIVE EACH COAT SEVERAL HOURS TO SET BEFORE APPLYING THE NEXT COAT THAT SHOULD FIX THE PROBLEM

Please visit www.swepcousa.com for a full range of products that can solve the problem. Their products have been used extensively here in nigeria and very successfully; temperatures and season quoted by you are similar with ours here.

See if you can locate a local distributor of their products in your area and chose the one that will solve the problem adequately.

Kabiyesi4life - Nigeria

Try these products from Kryton

http://www.kryton.com/support/learning/crystalline.php

Integral Crystalline Waterproofing.

Layering of materials.

How are you going to maintain 1:50 for 50 mm thick water-proof cement? Make a thicker cement at the middle? What kind of waterproofing for your new 50 mm thick cement?

Need to consider effect of additional loads to existing concrete roof.

And how much will it cost?

I have never seen a flat roof that stayed sealed in Europe, let alone where you are....

A pitch roof is the only way to go for the longterm fix and will give you some more storage/living area......

I have never seen a flat roof that stayed sealed in Europe.

Amen... Truly flat roofs are daft, generally they have a slight pitch and proper drainage. There was a fad some years back for flat roofs which were designed to stay wet...utter madness.

Del

Here's your solution:

www.sika.com

Wangito.

If the roof is flat, good luck.Water has to have someplace to go, and if it cannot get off, it will be inexorably pulled down.Membranes used to cover roofs must be perfectly sealed or leaks will result.The best remedy is expensive: A new roof.Shingle manufactures will not guarantee anything on less than 3/12 pitch.More pitch is better.

Hope this helps

NO...THE BEST SOLUTION IS CHEAP!

EPDM sheet, water based adhesive to stick it down, solvent based adhesive for joins, and 'formable rubber' for any weird joints/through holes/reinforcement..

I've done it on my extension roof which includes two pipes which penetrate for solar hot water.

Cheap, quick simple, 1 man job..... and the roof is ~ 3m x 14m

Del... trust me I'm an engineer.

I'll use the best grade polymer and try to go the cheap route. Maybe in summer I'll re-do the whole thing!

I'm gonna do a metal roof over the leaky roof and pitch it maybe 10-15 degrees. I woould like to do more but my mom will not like the absence of window space. I would upload some pic's and diagrams but, havin a hard time uploading!

I assume you mean pictures are difficult to upload, they must be in a normal .jpg format.....that poses no problems usually, let us know if you need any further help.

I'll take a few pic's of the Doggarn thing and try to upload, that way you can see the whole effect of wear and tear...

My Pop has tried everything, it's got so bad they're depressed. Lost all hope of keeping the house! I offered to buy but there's 4 other siblings and they're fighting T n' N.

Sleepless in PR

In ohio we used big sheets of rubber , I think they were 3/16ths inch thick. Works very very well. Be sure to flash the edges professionally, or water will run under the rubber. The sheets we used were about 20' x 20' but they say you can get any size you want. Cost back then was maybe $40.

The local builders supply had the sheets or ask around at hardware stores.

Flat roofs are the worst. But this solution has worked for many a years now.

hello everyone.

i have grown very fond of "grancrete". a little expensive, but bonds well with everything except plastic or glass. waterproof, no cold joints, sprayable. if you had not tried anything else, i feel it would have a better chance. still might work. email them and ask. their technical guy is "Jeff" his phone number in the U.S. is 919-641-3358.

I have over 50 years experience as a builder/developer....shopping centers and industrial buildings.

Best solution I have found is Dow Corning foam in place mono-cell foam ...a urethane product......best thing is it can be applied on a flat roof in increasing thickness to provide a slight slope to induce drainage........center crowned.... tapered toward edges........I even cured a sagging timber roof that ponded water this way...very light weight so induces little new mechanical load...

Be certain your contractor applicator has substantial experience in this process.

Foam is top sealed with a very elastic temperature resistant over coating that may, at your local, need re coating about 8 to 10 years...I have one 30,000 sq. ft building re-coated once....originally installed 1980..no leaks...very low pitch.

ONE GREAT ADVANTAGE IS THE INSULATIVE QUALITY THE FOAM PROVIDES..REDUCING "BELOW THE ROOF" TEMPRETURE....IN MY SOUTHERN CALIFORNIA CLIMATE BUILDINGS ARE MUCH COOLER/SUMMER TIME.

Warning...stay off the roof with foot traffic or wear soft shoes...

MR. GUY

One of the main problems is just that! Top floor is a terrace so there's always going to be traffic. I might go ahead and seal the upper roof and build a terrece roof on the first level. All suggestions will be considered although I'll have to go the less expensive route for now! Thank you all!

They have all been fine suggestions!

One of the good things about the sheet of rubber is that it can be installed wet if needs require it to avert further disaster. One can merely place it temporarily to stop the bleed so to speak and then wait for a dry day to install it properly. It can be rolled up and moved around . Fold the edges over the edge of the roof and nail it to side of house to avoid any punctures on top where it might seep and leak over time. Flash it well around the edges.

Its reasonably cheap too.

Traffic would over time puncture it also , you might consider making that area of the house off limits (others have had to do that).

Building any kind of pitch at all would be best and also not so hard if you have a dry day and some materials like 1/2 " plywood, tarpaper, shim boards , etc.

Sheet rubber (EPDM) can have slabs over the top to counter the traffic problem. This UK site has loads of stuff....I got my stuff from them.

I would call Tremco, a US manufacturer. They have the correct solution!

There is a company , Permalume, that used to make good stuff. There is another one Derbigum. I don't know anything about them. But I used Permalume afew times. It'll probably work for you. You roll it or spray it, it's plastic and seals pretty good.

I live in sunny south Florida and recently needed to replace the roofing on a low slope section of my house. (1/2" rise per foot) After to talking to the roofing "experts" I decided to do it myself. I found a product manufactured by Certinteed, called Flintlastic S/A (self adhesive) Ply Base. Because I was going over a nail-able roof material, I used a nail-able base sheet. Followed by a self adhesive mid ply and then a self adhesive cap sheet. The finished product is about 3/8" thick, and tough as nails. It is very pliable, the mid ply has an almost self healing quality to it. They also sell a similar base sheet that is designed to be used over non nail-able roofing materials. The products are listed as being made of modified bitumen. The web site lists very detailed procedures for attaching to the roofing structure. Try www.certinteed.com. I will concede to Del's knowledge of the subject, but feel that this product is designed for this specific application, and adhering the product to the roof will be as important as the waterproofing and expansion qualities of the product. Another manufacturer of quality roofing products is GAF. Good luck.

I would be inclined to try something like a spray on truck bed liner like a Rhino Liner. Not cheap but I bet it would keep the water out better.

The biggest problem is the fact that you can not keep water and moisture out but you sure can keep it in!

Travis

Hello Ron... and everyone else having roof sealing difficulties in Puerto Rico.

I bring to you an alternative to resin and tar (pertroleum) -based roof sealers.

The Crossco® Maxxi Seal™ is a fiber modified polyvinyl emulsion effective in waterproofing of roof and walls. It resists great changes of temperature, so PR's high temperatures shouldn't be of concern.

Also, here's a list of stores that handle that product with their phone numbers:
http://www.crosscopr.com/where-to-buy/

Hope this helps you all and happy renovations!