Commercial Go Over 800 Sq. Need Advice


#1

Customer wants to adhere another layer of rubber to existing .060 thats fifteen years old, Already one layer of tar/gravel and one layer rubber. Wondering if this would be a good option verse tear off. Obviously he would save a ton. He reseamed everything five years ago.


#2

Also considering offering a ten year warrany, would this last, any advice would be great.


#3

Whats the problem with the new EPDM now?


#4

Some holes forming and some seams starting to go again, it is a low traffic area, they are tired of repairs.


#5

With the previous moisture intrusion, I would say tear it off. Can you even go over EPDM without MF, ballast or a boardstock? I dont think I would like that if it were my roof. All of the existing problems could telegraph and occur in the new. EPDM likes to shrink, which would adversely affect your roof.

Start with a nuclear moisture scan.


#6

[quote=“AaronB.”]With the previous moisture intrusion, I would say tear it off. Can you even go over EPDM without MF, ballast or a boardstock? I dont think I would like that if it were my roof. All of the existing problems could telegraph and occur in the new. EPDM likes to shrink, which would adversely affect your roof.

Start with a nuclear moisture scan.[/quote]

I can use board stock if code will allow a third layer on a commercial steel building (Massachusetts) most likely not. The building owner is a friend of mine just trying to save him some money. That’s why I was suggesting rubber to rubber. I know the best way is a tear off and thats what I’ll do if it comes down to it. Yes there are a couple soft spots. Thank you for any help.


#7

tear it off


#8

if present system is fully glued down, you can consider applying a liquid applied rubber with polyester fabric and get a ten year warranty. the dry mil is around 14 to 16 and qualifies for energy star (white).


#9

what liquid applied rubber? Crumb rubber? Liquid EPDM like for sealing RV roof seams?


#10

TEAR IT OFF!!!


#11

Whats that special primer they use for EPDM, dacroof, and do you think it works, and will work at 2 Gallons per square for more than a couple of years?

If a temp fix is sought, then by all means, use whatever “rubber” he is talking about.

I know that acrylics will easily lose millage at the approximate rate of 3-7 mil per year. (from what I have read)


#12

Hydro stop. No tear off. Epdm primer. no weight. waterproof . NDL warranty.


#13

How does the EPDM primer work for that system?


#14

Better yet, how does the NDL warranty work for that system? To think HydroStop will warrant the roof against leaks when their material is applied overtop of a failing EPDM roof membrane with entrapped moisture makes me think b.s. Sorry, but I don’t know of any manufacturer that is going to give you a No Dollar Limit warranty when you install their material over an unsuitable substrate. Sure, they may warrant their material, but if the EPDM membrane shrinks and rips open a lap causing the HydroStop to fail, you can bet it won’t be covered under the warranty. JMTC


#15

tear it off


#16

If you are concerned about the substrate shrinking then I suppose you would need to attach it. The post didnt single that possibility out. A fully adhered system isnt going to have that risk. In regards to trapped water, What difference does it make what the substrate is. Plywood has a moisture content of nearly 20%. when it hasnt been rained on recently. you apply all kinds of products over that. As a contractor you should be dillegent to make certain you are applying any product over a sound substrate. Sound doesnt mean “not currently leaking”. Im telling you again that Hydro Stop warranties their projects with NDLs over EPDM. If it were my spec over EPDM and it was a mechanically fastened system, I would install new perimeter metal securely fastened over the top of the EPDM and then apply the Premium coat system over new perimeter metal. The PC system is very very strong when cured. Because it is fully reinforced and fully adhered makes it Strong enough to keep EPDM from moving. Or you can do what the BOSS says and tear it off. Just trying to help. Call Hydrostop if you think im full of it.

RE the Primer… it breaks down the carbon and mica on the EPDM and then you wash it off. That is it. Just did the East Bay Tire Company warehouse, 1100 sqs, over carlisle. It isnt really a primer, I suppose they just dont know what else to call it. More like a cleaner.


#17

substrate failures ALWAYS worry me when my name is on the roof. It SHOULD worry all of you, also.

Now the real issues with fluid applieds come down to tensile strength, adhesion, and hardness.

My roofing formulation’s tensile at 48 mil is 2094 psi, according to the testing data. Thats a lot. The adhesive properties will outperform any bonding adhesive. at 300% elongation, plaily, you cannot beat it mil for mil, or even gallon for gallon.

If you wish for a cool roof, we can do that, too.

All in all, I say tear it off, install the longest lasting sustainable system you can, and take the 39 year depreciation. The only roof I know of that can do this is SPF with warranties that can be renewed, and every renewal is eligible for immediate full depreciation at the time it is performed. This is the only way to beat the tax rules, and keep the roofing costs to a minimum over the life of the building.


#18

blah blah blah…just tear it off…just tear it off


#19

TEAR THE DAMN THING OFF ALREADY. DAMN


#20

LOL… :slight_smile: