What Roof Coating do I use for a Flat Roof?

I have a 10 year old flat roof covering 1500 sq. ft. of my home, it is a black rubber membrane.

It has never been kept up with so there is cracking and some leaking... I already went up and patched spots with a fibered roof cement, but now that it is getting decently warm I want to coat the whole thing to seal it all off.

What perticular kind of coating do I use?

I read somewhere that the roof should be "sealed" every couple of years... well this have never been sealed.

Thanks all!

 

If you want to continue with having to seal the roof every few years, then a coating like Snow Roof will do a decent job. Check with a local lumber yard as well as a big box store to see what particular brands are available.

If you are tired of coating it every few years, cover it with metal roofing.

 

Ok, I looked up the Snow Roof and it says it's a ruberized type undercoat... the other items that popped up were Aluminum roof paint/coating.

I seen a couple different Aluminium roof coatings when I was at the store but thought it was just for an aluminum roof. None of the aluminum coatings/paint is fibered.

Is this coating/paint nice and liquidy so I can just roller it on or use a broom to brush it everywhere? I need something that will fill these pin holes and small cracks.

Thanks for the help!

 

By the way, I only need it to last for a little over 2 years before I sell the home.

 

I'm not familiar with the Snow Roof brand but it appears to be an elastromeric coating. They do a decent job of waterproofing the substrate they are applied to. As the name implies, it's an elastic coating that will give some as the substrate moves. While I've used a lot of elastromeric coatings on exterior walls, I have limited experience with it on roofs. It's thicker than normal paint and won't go as far per gallon [the label should indicate coverage rate] I'd expect it to hold up for more than 2 yrs although it likely can be damaged by hail.

 

It's elastomeric, it goes on thick, and it last several years. Apply it with long handled rollers and don't paint yourself into a corner!!

Years ago, I did a couple of mobile home or flat roofs with it. It's all in the planning. Prop the ladder up near the center of the roof, then work from both end to the middle, where the ladder is.

Integraoligist, since you are planning on selling in a couple of years, you can look at this thing 2 ways. Do something cheap now that'll last a couple years and leave it for the next guy to deal with. That won't add any value to the place. OR, step up and pay the $$ to do the metal. Chances are that when you sell it, the metal will add more to the selling price than you paid for it. Next guy will see the meatl, realize he doesn't have to mess with it in his lifetime, and pay a premium for it. It's a roll of the dice, especially in this market. Who knows where prices will be or what they'll be doing in 2 years.

 

Well as far as resale goes... even with a nice metal roof I don't believe it will help up the price. This home is so old with so musch halfassed work done to it that the next person to buy it will probebly just tear it down anyway.

I'll be stopping by Menards tomorrow to see which of the 15 different kinds of roof coating will work. As long as it says elastic somewhere on the can we should be good to go. I know most of them are thick like tar so I'll just shake all the cans until one sounds liquidy.
I was just worried because the couple that I found said it was for an aluminum roof. Now that it doesn't matter we should be good to go.

Today it's 36 degrees here.... I know it should be as hot as possible when I roller this stuff on... but that wont be for months. So what do you suggest the lowest temp is I should apply this at? 60f?

 

Generally the 'silver' colored roof coatings are for metal roofs. They used to be impregnated with asbestos but now they use asphalt instead. I'm sure it will say somewhere on the label that it cleans up with paint thinner.

Elastromeric roof coatings are normally white and will clean up with water. It can be used on both types of roofs although a metal roof should have a solvent based primer applied first [prevents rust from bleeding thru]

Usually the tar based coatings will come in a metal bucket and the elastromeric in a plastic bucket - not always, but usually

 

Was looking at the Home Depot website to get some pricing before I go to Menards and noticed there are basically 2 diffrent one's that are used for this:

This is an actual "Rubberized Coating"
Flexx-Bond 5-Gallon Rubberized Coating and Adhesive - 1365-GA at The Home Depot

Then they have the "Elastomeric Coating"
5-Gallon Ultra-White Elastomeric Roof Coating - SK-7705 at The Home Depot

My roof bascailly looks like this, but about 10x's larger and has a lot more cracking from the sun beating on it. It does pool water in certian spots like this photo as well.
http://lh6.ggpht.com/_vHcOrKc5YHU/SA...g/DSC07237.JPG

 

Either should work. The 1st bucket is basically roller grade tar, the 2nd bucket is an elastromeric paint. Both should seal the leaks although the elastromeric will reflect the sun/heat possibly resulting in cooler temps in the house.

 

It's funny how the first one says it's Rubberized coating, but does not have the word Elastomeric anywhere on the can... and the same for the Elastomeric can not saying anything about rubber.

lol.

 

That's because while similar in some aspects, they are 2 totally different products. The rubber is a tar base and cleans up with paint thinner, the elastromeric coating is latex based and cleans up with water.

 

I was just up on the roof to check it out. The coating that used last October apparently dosent "dry". I steped in it and it got all over my shoe. When I touch the stuff it sticks to my finger.
I used "Fibered Roof and Foundation Coating"

I thought that was suppose to dry Hard (because of the fibers)?

If I roll this new stuff all over the roof, will it dry in a day so I can walk on it again or will it remain wet like this Fibered one I put on 5 months ago?

Thanks again!

 

The roof and foundation tar dries but if it gets enough heat [sunlight] it will soften up some, it will dry again when the temps cool off. It's not really a coating that is expected to be walked on. Elastromeric is more of a paint that flexes some and seals minor leaks. It will not soften up at all [unless a stripper or certain solvents are spilled on it] once it has dried.

 

ah ok, it was 40F out when I was up there and was nice and sticky, of course it's black and in the middle of the day so it must of gotten nice and warm.

I was at Menards early and the only liquid stuff they had that you could roller on was "Roof Works Fibered Aluminum Roof & Mobile Home Coating".

But it does not say anything about rubber or elastromeric. It does say it's dries Silver but thats about it.

 

The aluminum fibered coating is kind of a cross between paint and liquid tar. It's normally used for coating mobile home roofs or old metal roofs, especially ones that are rusty. While it will bond to your fibered roof tar, I don't know that it would be that good of choice for coating your roof.

 

i'm suprised Menards dosent have what I need. Looks like i'm going to have to make the long hall to Home Depot to get the correct stuff.
Flexx-Bond 5-Gallon Rubberized Coating and Adhesive - 1365-GA at The Home Depot

 

That should be similar to what you currently have on your roof.

Menards would be the long haul around here, I've never been in one of their stores, not sure I've even seen one

 

You make me want to drop the extra cash on the elastomeric stuff... i found it's actual website here:
Sta-Kool® SK-780 - Siliconized White Elastomeric Roof Coating

It dosent say how many sq. ft. it goes... but at least this will dry to where I can walk on it and water test this.

 

from their website;
Porous surfaces including foam, concrete, tile, roll roofing, and previously coated surfaces 50-75 sq. ft./gal

 

maybe i can add some water to that to stretch it out... because 50-75 sq. ft is nothing! ahhhhhh

What kind of metal roofing would I be able to put on there? That coragated tin roof or something else?

 

While you could thin the elastromeric paint some - the more you thin it, the more weatherproofing properties you loose

I don't know what type of metal would work on a flat roof.

 

I am going to get a few cans of this stuff today, and this morning I got an email from the manufacturer about it.
They said that the Elastomeric and the Rubber coating will not work well for my application because it's a Bit roof and has some standing puddles.

They said this is the best options, brush applied to work the fibers into the roof:
Shop BLACK JACK 4.7 Gallon Fibered Roof and Foundation Coating at Lowes.com

I dont understand the "working the fibers into the roof"... i'm guessing it's like fiberglass and gouges itself into the roofing material? O yes, he also said it will cure in 48 hours so I will be able to stand on it.

 

I assume the fibers help the tar to stick together. Brush [or maybe over rolling] would help to disperse the fibers better. While it might dry enough to walk on if 48 hrs, I'm not sure that it wouldn't get tacky when reheated from the sun.

 

Yeah, I'm not sure what the difference is between this and what I already have patched on the roof. I just used a 2x4 to spread the other brand over the places that looked it may be leaking from. His main point was that because water does pool in certain areas, that the elecsomeric and the rubber one's would start to breakdown, i assume because they are both water-based.

 

I would think that pooling water would be hard on any type of coating that is applied although a tar based coating [which is made from petroleum] should handle it better than a latex based coating.

 

Ok, so I went and got a few cans of the petroleum based kind... was looking for a "roof brush" and of course the only one they have is 4" wide.

4" wide? Seriously? It will take my 4 days straight brush this onto the rood with a 4" brush.

Can I just use a moderately stiff push broom for this function? Something that feels about the same stiffness as this Roof brush? Or do I have to use this "natural" type bristle 4" brush?

 

You are dealing with a flat roof. Applying any type of coating and keeping the low spots out of it will be next to impossible. The larger the broom that you use, the more low spots you are going to have. That will lead to the water pooling and creating leaks at some point in the roofing. Like marksr said, a tar based coating will handle that better than latex.

My guess is that at some point you are just going to say "enough" and install a metal roof and be finished with it.

 

I'd apply the coating with a roller - a brush would be too much work

If I felt that the roller didn't do a good job of dispersing the fibers - I'd use a broom after it was applied with the roller.

 

What kind of metal roof is this that you speak of?

 

Any solid panel long enough to span the shortest direction, or span 1/2 of the shortest direction and put a ridge in the center. Depending on just how "flat" your roof is, you may need to build a slight bit more slope into it. Metal panels need very little slope -- 1/2"/ft., 3/4"/ft. -- enough to get the water to flow off of them. Google "metal roofing material".

 

Hey Integraoligist, I'm having the same problem with my roof as well. My roof is rubberized, but it's been silver coated so I can't see what's underneath the silver. I've tried patching it up from time to time and recently I just tried the:

BLACK JACK 4.7 Gallon Fibered Roof and Foundation Coating (from lowes)

It's been about a week since I applied it, but it doesn't dry to a hard enough state to walk on. It's still pretty mushy and I bet if I were to walk on it, it should leave foot imprints and would probably stick to the bottom of my boots too.

I'm also trying to find any type of substance that I can coat my roof with that would seal my roof in while I can walk on it. I don't want to use metal panels since my roof isn't completely flat (it's raised at and angle so that water would drain off of the back section). I'm at a point where I'm ready to buy adhesive coating and lay new rolls of rubber over it.

P.S. I live in PA and the Lowes near me has 7" brushes (in the roofing section) for about $5. 4" is a bit too small and will take you ages to apply it.

 

mtoda,

Welcome to the forums.

There's no reason that you couldn't use metal roofing if you so choose.

How thick did you apply each coat of the Black Jack? If you applied one thick coat, it'll take a long time for it to cure. Had you applied several thin coats and allowed each to dry, ...

 

I looked up the metal roofing, Lowes has a plastic style that would seem like it would work pretty good. People have used it over their porches with not problems or cracking even when a tree branch hit it.

If it were to keep this house for more then 5 years I would spend the money to do this, but seeing as though it's a tear-down and am only going to be here the next 2-years, the cheapest route is the best for me right now.

I picked up 3 cans of the fibered coating, and yes the 4" brush... i still have yet to apply it because the weather has dropped to 30's again. The manufacturer. said not to apply until it's at least 50F. So I still have at LEAST another week before i can apply it.

MTODA, I know what you are talking about, i used that Fibered Cement last October and it has NEVER cured. In the thick (1/4") areas and the super thin painted areas... none of it is hard.

I figure the "cement" would have hardened long before any other type. These 3 new cans i have a "coating" not cement. We'll see if that makes a difference.

 

I applied the recommended dosage as the can instructed. A can (5 gal) spreads about 250sq feet and the roof area that I applied to is around 260sq feet. Still... really mushy... I'm going to try to apply another layer of silver coat to it:

Shop BLACK JACK 4.75 Gallon Silver Seal 300 Fibered Aluminum Roof Coating at Lowes.com

and see what that does. At least it should keep the place a bit cooler during the summer. I don't think applying that would help me walk on it. I still need a walkable surface. I just don't want to go the metal panel rout if there is a coating I could get. Also my roof is a low sloping roof (Surface: 12 x 26 feet, with one end of the roof about 1-2 feet higher than the other end to create that slope). I'm worried if I did the metal or plastic panels wrong, I would mess up the water flow to the back of it where water drains off of.

 

The aluminum roof coating will dry better than the black jack because of the paint that is mixed in it but it won't dry as hard as regular paint and it won't stop the tar beneath the aluminum paint from still being soft. It will help but not cure