Silicone vs. asphalt for flat roof

[Bwana]

I've been trying to understand the pro's and con's of these two flat roof coating options but am having a surprisingly difficult time getting details. Searching here has limited info and Google turns up mostly sales pitches (what a surprise )

I currently have old school asphalt/gravel on most of the existing house and it's about done, gone beyond it's design life, so it needs replacing. On the new garages I have what appears to be heavy asphalt sheeting, applied with high heat and well sealed. No gravel, just the tan back side of the sheeting.

I have one guy that has given me a bid for "silicone" material instead of asphalt. The existing gravel is removed and the silicone then appears to be poured/sprayed on and ends up almost as one piece. It supposedly has a lifetime guarantee, he will give it seven years. It's about $20k for a 2,500 sq ft

So, how old is the silicone technology? I can't find when it was first developed, but it only appears to have been around for a few years. If the technology is so new, how do they figure a "lifetime" guarantee? What's the track record? Is it demonstrably better that the current technology for asphalt, which appears to be pretty good?

 

[4xdog]

It's not an area where I have any expertise (except for the polymer science part), but why not consider EPDM?

 

[Bwana]

I've seen that referenced too but have zero idea of what it is except for deciphering the acronym.

 

[Stuart in MN]

EPDM = rubber roof. It come in a big roll, and is glued down to the roof deck. I have it on the roof of my back porch, it's durable and long lasting.

 

[Angelfire]

I too had asphalt/gravel but it was about done. Quotes from roofers couldn't give more than a 3-5 year warranty to redo it. Many claimed the product formulations over the years have changed and consequently, the warranties were significantly reduced. I ultimately went with TPO. It's been down for ~9 years now in a very high UV region and has held up great so far. I didn't consider silicone (not even sure it was an option then?).
Cheers.

 

[kaymccampbell]

Never seen silicone roofing. The most enduring I've seen was urethane foam, with a urethane overcoat. 10 years between touchups.

 

[zendriver]

This business is been open in my hometown for about 40+ years.

Not sure what is involved with it being “acrylic” but it looks like silicone caulking after applied.

http://www.polarsealinc.com

I work commercial HVAC for a while and most of the commercial flat roofs seem to be using the rubber seamed roll material that was white.

I don’t have a flat roof but if I did I think I’d be looking at that supposed to be a “one and done” solution.


Sent from my iPhone using The Garage Journal mobile app

 

[dogdog]

I brushed a good coat of White Silicon.. Henry brand I think... not the top top rated... It is pretty decent.. roof cool by a lot during hot Summer days. Smells like HF for a while.

Not sure about going just thick coat of silicon instead of the EDM... I know the silicon for brushing on is not as tough.. maybe ask them for a sample.

 

[Bwana]

I too had asphalt/gravel but it was about done. Quotes from roofers couldn't give more than a 3-5 year warranty to redo it. Many claimed the product formulations over the years have changed and consequently, the warranties were significantly reduced. I ultimately went with TPO. It's been down for ~9 years now in a very high UV region and has held up great so far. I didn't consider silicone (not even sure it was an option then?).
Cheers.

Hi neighbor, (yes, I finally updated my profile ).

What is TPO?

You're just up the hill from us and that extra 3,000 feet or so must be hell with the UV rays, they're bad enough here at 7,000. Did a local contractor put it on or was it a DIY?

 

[joey1320]

I've been trying to understand the pro's and con's of these two flat roof coating options but am having a surprisingly difficult time getting details. Searching here has limited info and Google turns up mostly sales pitches (what a surprise )

I currently have old school asphalt/gravel on most of the existing house and it's about done, gone beyond it's design life, so it needs replacing. On the new garages I have what appears to be heavy asphalt sheeting, applied with high heat and well sealed. No gravel, just the tan back side of the sheeting.

I have one guy that has given me a bid for "silicone" material instead of asphalt. The existing gravel is removed and the silicone then appears to be poured/sprayed on and ends up almost as one piece. It supposedly has a lifetime guarantee, he will give it seven years. It's about $20k for a 2,500 sq ft

So, how old is the silicone technology? I can't find when it was first developed, but it only appears to have been around for a few years. If the technology is so new, how do they figure a "lifetime" guarantee? What's the track record? Is it demonstrably better that the current technology for asphalt, which appears to be pretty good?

It this something you'd consider doing yourself?


You can get the Henry's silicone roof cover at Home Depot between $90-240 - depending on which one you get.

I used a half gallon on my pop up camper's roof that had a leak and it's been great for the last two years. Just clean, roll and let it dry.

You can also use a sprayer.

$20k is a hard pill to swallow. I would consider doing it myself.


https://www.homedepot.com/p/Henry-4...ilicone-Gray-Roof-Coating-HE887G018/302865617

 

[mobiledynamics]

How many layers on the roof. Planning a tearoff ?
Binder. New Cap Sheet.
or Just Spray and Pray

EPDM, TPO, Torch
I prefer torch

IMO. Finding a good roofer IMO is 75% of your problem...Then executing/installing correctly is a whole nother fiasco. You have a great experience on the guy bidding the job.

Come job day, all you see are helpers doing most of the work...

Or as the home owner itself, being able to see it installed and whether to understand if it's being installed correctly during is extremely helpful...IME, it's best to see the thing being done/methods/etc. Heck with the easy IP cameras that exist out there, I guess u can mock something up to view it on a screen..


Torching is a art. Rolling it out is a art....Getting correct bleedout is a art...

Out here, at least 4X easily for the footage on a full tearoff. Material aside, getting it installed properly is key...

 

[dcg9381]

RVs have EPDM or TPO (roll on material) roofs. I hate both (for RV applications). For fixed shops, they probably work better, but the RV aftermarket industry has come up with many roll-on coating materials that are superior... I wonder if any of these are available?

 

[mobiledynamics]

The silicone stuff is interesting...probably great for repairs. I dunno for a new fix, what is the MIL thickness on that stuff for the longevity/lifespan of whatever the warranty is they are offering or like all things in life, will they actually show up for a warranty followup

 

[dogdog]

I think the OP might have gotten a slick sales pitch...or something lost in translation... or maybe there is a new thing out there...

The Silicon roof coating is the brush or spray on top coating for the roof, if the contractor are ripping off what ever roofing material they would still needed the regular roofing installed first what ever EPDM/TPO or what ever... Make sure you choose those wisely. Make sure you get that straight and don't let them overwhelm you with tech-no-ma-logical terms. My roof is about 2500 sqft. about 20 buckets... and back then was $190 per bucket volume discount if I buy 10 or more at the time.... and I did a roll on about 2015 or something.. I remember asking who got the white roof coating here as well...


https://westroofingsystems.com/pros-and-cons-to-roof-coatings/

A silicone roof coating system is a single layer (applied in one or two coats) of silicone that’s rolled or sprayed on as a liquid to fill in cracks, blisters, and seams.

This was my thread asking... I bought and DIY Roll on late Summer that same year.

https://www.garagejournal.com/forum/showthread.php?t=255992&highlight=HENRY

 

[Angelfire]

Hi neighbor, (yes, I finally updated my profile ).

What is TPO?

You're just up the hill from us and that extra 3,000 feet or so must be hell with the UV rays, they're bad enough here at 7,000. Did a local contractor put it on or was it a DIY?

Hiya. I'm actually in ABQ (but have a place in AF as well, metal roof there). I actually find the UV to be worse here in ABQ vs. in AF. I've no data to support this but stuff just seems to degrade much faster here vs. up there. Anyway, TPO is Thermoplastic Polyolefin. It had a bit of a rocky start with some early failures but when I was looking, it appeared the manufacturers had worked out most of their issues. PVC was another option that appeared to possibly perform a bit better but it was significantly more expensive when I got quotes. I really do like the white color of the roof as it has helped lower the temp in the house during the summer considerably.
Cheers

 

[Ralf11]

I thought everybody was replacing the asphalt roofs with membranes (?)

 

[Grimpala]

I just finished ~500,000 ft' of re-roof. We removed an existing built up asphalt roof and coated with 55 mils of silicone, with a 30 year warranty on the new roof. Silicone is perfect for a flat roof, you'll still need the insulation and whatnot underneath, but it will last quite a while, plus in white, you reap some reflective benefits.

 

[dogdog]

I just finished ~500,000 ft' of re-roof. We removed an existing built up asphalt roof and coated with 55 mils of silicone, with a 30 year warranty on the new roof. Silicone is perfect for a flat roof, you'll still need the insulation and whatnot underneath, but it will last quite a while, plus in white, you reap some reflective benefits.

is that 5.5mil or 55mil ? Roll on , spray on or it come with a sheet of them... 55mil seems to be really thick as in over 2" thick..

This is the top coating right not the whole roofing.

Which brand ?

 

[DTE]

I owned a building with a tar and gravel flat roof, had it torn of to the decking the roofers screwed down black board insulation and installed white Firestone brand roofing material that was about 5 to 6 feet wide and hot air welded it together at the seams and when I sold the building 25 years later it was still good.

 

[Angelfire]

is that 5.5mil or 55mil ? Roll on , spray on or it come with a sheet of them... 55mil seems to be really thick as in over 2" thick..

55 mils is about 1/16" (0.055")
Cheers.

 

[dogdog]

55 mils is about 1/16" (0.055")
Cheers.

Ah... ok.. thanks thought it was millimeters... that is about 2 or 3 coat... if it was the sillycon stuff.

 

[Bwana]

OK, thanks for the answers. One more question: can you walk repeatedly on a silicon roof? I don't mean marching an army with regular traffic, just walking around sometimes to say clean the TV dish or check the mini-split compressors. I'm also planning on installing solar panels, can they be installed on top of the silicon? I've seen asphalt like this so I know it works.

 

[4xdog]

...a silicon roof...

Note that in the US we use the term "silicone" for the polymeric material made from a silicon backbone. Silicon is a semimetallic element used in its pure form for things like microchips and photovoltaic panels. Given that we're talking about both roofing membranes and solar power in this thread, it'll probably be helpful to keep the terms as clear as possible.

(Our friends in the UK do use "silicon" for the polymer -- but it's also ah-loo-min-ee-um over there, too...)

 

[dogdog]

OK, thanks for the answers. One more question: can you walk repeatedly on a silicon roof? I don't mean marching an army with regular traffic, just walking around sometimes to say clean the TV dish or check the mini-split compressors. I'm also planning on installing solar panels, can they be installed on top of the silicon? I've seen asphalt like this so I know it works.

^^^ LOL walking on it when it is dried for regular maintenance sweep, snow shovel etc --> Yes..

^^^ heavy foot traffic like hosting a marching band on the roof top party... --> NO

Prep is everything... pressure wash etc and wipe any oily spots, heavy soiled before application