EPDM over current failed BUR system?

Got a call today to look at a building. I saw the old BUR on the building has been patched numerous times, is blistering, ponding, etc. They have leaks all over. It’s not a huge building by any means about 20 square.

They are not looking to remove the old roof but to go right on top. I’m not sure about this as any EPDM that we have laid has been on fresh wood, HD fiberboard, or polyisocyanurate board.

We get wind gusts about 70MPH max. I was thinking fully adhered. The ponding water issue needs to go away. Which is why I was thinking tearing off the existing roof. It is just one layer of BUR. It is fairly thin as well. I think it would be a peach job to rip it off, but everything now a days seems to be about cost.

There seems to be water trapped under the old BUR but for the most part the decking seems to be in good shape. Maybe a small soft 1’x1’ spot where the worst leak is. They were thinking cutting this spot out, patching and putting 2" polyisocyanurate board over it then applying fully adhered .060 EPDM over it.

Is this a bad idea?

No, I do it every day! Remove all the blisters w/a scratch bar or rip shovel, rake out the trash in the gravel, fill the low spots w/ gravel. If the gravel is real thick & heavy sweep & remove the heavy thick gravel. Then install 1/2’’ poly iso board, love the stuff! Why 2" iso, that’s expensive & not needed. Then plate & screw down w/HD screws. Then install the EPDM rubber with a system of your choice. Fully adhered is best but I like mechanically attached. You can save a lot of $$$ in labor & glue!!! That’s the difference in getting the bid or not!!! Sometimes you can even glue to the old edge metal, run the rubber down the face, & then term bar w/self tapping sheet metal screws or deck screws. That saves a lot of $$$ too not having to fab metal, install metal, & strip in w/expensive 5 or 6’’ peel n stick. That last method is mainly for low budget jobs like factories or triple deckers in the ghetto. Customers who don’t care & don’t want to spend the $$$.

No need for a slip sheet?

The roof doesn’t have gravel on it, it was smooth.

Mech. fastened is out of the questions since Versico who’s EPDM I would be using says no mech fastened epdm with polyiso on reroof with smooth under right in their installation somewhere. I was looking it up.

It’s probably best to just rip it, it’s not a bad rip. I’m going to spec out 1.5" polyiso fully adhered. It has some ponding that is around and I would like that to go away, so the thicker board should level the roof out better.

Any other thoughts? If he want’s to be cheap cheap… I can give him a 2 ply flintlastic system price… heh. There is one heat exhaust pipe that is 8" diameter so I’m not sure with modified systems what to do there since the biggest I’ve done was a 6" pipe. The supply house doesn’t have a collar for anything over a 4-6" pipe…?

No Axe, no need for a slip sheet. Just 1/2’’ iso. RP some customers can’t afford a rip, or don’t want to pay the money. I just lost a job I was sure I had, do to that. Why does it have to be Versico? I’ve done go overs w/Versico TPO mechanically attached w/parana plates. They can’t tell u no go overs, as long as u use hd screws. Idk who telling u this stuff? Versico is a subsidiary of Carlise, & Carlisle allows go overs. WeatherBond is issueing applicator’s licenses rt now. Grab one & get a low applicator’s #. Use 10x100 of .045 reinforced or 10x50’s & mechanically attached it. Hell, if its only a lousy 20 sqs. go ahead & glue it. That’s only 4 or 5 pails of bonding. An extra $500 for materials, not counting labor & roller naps & etc.

They probably want to use 2" for the insulation purposes, I’m assuming. Otherwise, 1/2" HD.

I wouldn’t use 45mil unless it was a spec’d for a 10 year or less roof. It’s not that much more.

Ddubya, the Carlisle .045 reinforced is nice stuff. I’ve got to do a rip n replace tomorrow. Someone installed tapered insul over a exhististing epdm rubber roof & never sliced it up prior installing the tapered epdm new roof around 6 years ago. However, they did this over a kitchen & bathroom so they heat from below & condensation is causing problems that appear like leaks. The insul is soaked from the inside upwards. Once the heavy deck was removed the roof was heaving badly.

[quote=“RPGC”]The roof doesn’t have gravel on it, it was smooth.

Mech. fastened is out of the questions since Versico who’s EPDM I would be using says no mech fastened epdm with polyiso on reroof with smooth under right in their installation somewhere. I was looking it up.
[/quote]

How do you even get a warranty on a EPDM under 50 square?

Like every warranty, you got to pay for it!

“Any other thoughts? If he want’s to be cheap cheap… I can give him a 2 ply flintlastic system price… heh.”

If conditions allow then go right over the existing with Fleeceback EPDM using FAST dual cartridge adhesive.

On a side note, you can get warranty’s for under 50 sq. I think minimum is 20? (Firestone) but good luck getting anything on a residential job.

[quote=“Tar Monkey”]**

On a side note, you can get warranty’s for under 50 sq. I think minimum is 20? (Firestone) but good luck getting anything on a residential job.**

I know you can get a membrane warranty for any size, but most manufacturers I thought was over 50 square for a total system warranty?[/quote]

I been shingling for 12 years and just started last year with a big commercial company so excuse my ignorance, but is this why we slice up the rubber when we are doing a go over? To prevent condensation? Are there any other things that can happen if you dont?

Ya, Fourthcliff. I went on one roof a couple of weeks ago & someone tried pulling that off. You got to slice up the old e.p.d.m., p.v.c., or t.p.o. Otherwise heat & condensation build up & get trapped between the two roof systems. This one roof was badly heaving, it was even lifting up the loose lay pressure treated deck that was on it!

So long as its not coal tar, just tear it off.