How to flash roof to stucco?


#1

I am going to try and install this roof myself Certainteed SA 3 ply system I have never done this before it is a low slope roof 1/2 every 12 .
What I need help with is how to flash up against the house which is stucco .
I have a chimney to go around to .
Not sure how many plys I should run up the stucco ?
And the best way to apply the flashing ?
Reglet cut in the stucco or other ways to do this ?


#2

Use a surface mount gum lip counter flashing on the stucco, the chimney you can cut a raggle and use standard counter flashing techniques.

EPDM is a better material, is cheaper, and will last longer than self adhered modified.


#3

I would use “cant strip” along the angle changes. That is cheap and available at most roof suppliers (or sub for 1x3/1x4’s) You could then use termination bar to secure to both the wall and chimney. In some cases, we have also cut a riglet into stucco and made a counter flashing.

Certainteed has a very detailed install manual and includes roof to wall details. Definitely worth downloading the PDF. You may want to consider having a small propane torch handy (like a plumber uses) for detailing the cap sheet around the chimney.


#4

This is helpful I will use cant strip and check out termination bar for wall and chimney , I need to read up on EPDM not sure I can do that by myself


#5

Trouble with DIY and single ply like EPDM or TPO is you will need more technical experience around those chimney corners. You will also need a hand full of small amounts of cleaner/primer/glue which may be a waste of money (since you dont need much).

I personally think the Flintastic is more DIY friendly. Good news is when this first system expires, you can always renew it with GacoFlex S2000 or Gaco Roof.


#6

Capitalroofer . I been thinking allot about those corners. I decided to go with the EPDM found a full sheet to cover the whole roof on Amazon for under 500 bucks. I hope I can find some quarts for the primer and glue. This will be a first time experience hoping it goes smoothly . After reading as much as I could it seemed the EPDM was cheaper and would last longer . I have never installed EPDM or Flintastic . From what I watched I would agree with You Flintastic is easier to install. Thanks for the tip on the GacoFlex S2000 interesting product.


#7

Epdm will last longer than sa in theory, if properly installed and in the right conditions. Not a first time diy project I would recommend epically with a chimney in the middle of the mix…just my two cents


#8

You should talk to a local roofing supply house – they probably won’t sell you primer by the quart, but you might be able to get a gallon. If you have any seams you should be using double-sided tape rather than black glue anyhow.

You may be able to get some pre-cut self-adhesive uncured (flexible) patches for those outside corners – I know firestone was pushing those awhile back as saving labour, they are sold individually so would be way cheaper than buying a whole roll.

Obviously you will want to give yourself a smoother substrate around the parts of the chimney covered with EPDM – you don’t normally need cant strips with single-ply, but you should cover the first couple bricks with metal or plywood before your roof goes on, then counterflash (or term bar) above this.

Also you’re gonna want to do a detailed inspection of that roof deck that no nails are partly driven or likely to work loose – screws are better but that is probably not what you have there.

Good luck, it’s not rocket science but there is not much margin for error with flat work in general, single ply particularly…


#9

Its been a while since i’ve messed with EPDM (im in the south) but I doubt it can go directly to OSB??


#10

It can, I’ve seen it spec’d with manufacturers approval.

Obviously iso is preferable, but actually OSB is a pretty good substrate for adhered – really sticky! I wouldn’t loose lay it though.

IIRC part of that spec was that the OSB be screwed using approved plates, same as iso, to prevent issues with nails backing out, this would be my only concern on a residential job like this. That and ventilation, I guess.


#11

Thanks good advice I used screws on the corners and nail gun in the field with ribbed shanked nails and H clips on the spans . I will give it a good look , So are you saying to cover the chimney with Plywood and then put my EPDM roof on over it and then flash over the plywood and EPDM ? Maybe I should attach the plywood along the stucco as well ? Whats the best way to attach the plywood to the chimney ?


#12

Thanks JKF really good advice keep it coming


#13

What do you mean you wouldn’t loose lay it ?


#14

Yep, that is roughly what I meant on the chimney – wouldn’t bother with that on the stucco, it looks pretty smooth already so just term bar should be fine. I’d probably put the top of the plywood near to even with the next mortar joint up, then cut a kerf into that with a diamond blade so your counterflashing can line up with the top of the plywood.

Re: loose laid, there are a few different ways to secure the membrane to the roof. If I were doing this I would strongly prefer “adhered”, which amounts to glueing the membrane to the roof deck with contact cement. I think you said you want to do this in one piece though, which would mix poorly with a first time installer. :wink: There is a definite knack to working with contact cement, and it’s not something I can really talk you through.

“Loose laid” would be a ballasted application – more or less you lay out the membrane, seal any seams/corners, then put large smooth rocks (or concrete pavers) on the membrane to hold it down. I would see problems here as any movement in the system could cause the membrane to rub up against the deck, causing wear/leaks at any rough or sharp spot. (which will be hard to completely eliminate with OSB)

“Mechanically fastened” could work OK here – you still need to make friends with your local roofing supplier, as you need some semi-special screws & metal battens. Basically you screw a bunch of holes in your nice new roof, then cover them with seam tape. I don’t have much experience with this one, but it’s cheap and easy.

If I were doing this roof I would go over that deck with 1" isocyanurate board (or other flat roofing product) fastened with manufacturer approved screws & plates, then adhere the membrane to that & cover any outside corners with uncured flashing tape. I have most of these things in my shed though, so the expense might start to add up on you.

For you I would try pretty hard to afford going over the deck with a proper recovery board of some kind; if not, then get super anal about anything that looks sharp or rough on the roof, then either mechanically fasten or adhere.

If you choose to adhere, I would suggest that you go with ten foot strips of EPDM, and have a few seams. (Sealed with double sided tape). This will be plenty frustrating enough for a beginner to glue down, without trying to handle a single large piece.

How big is this roof anyhow?

I’m happy to walk you through this as much as possible, but I do suggest you get friendly with the guys at some place local to you like ABC Supply. They (probably) won’t be roofers, but they will know what roofers buy and should be able to help you out with what is locally available. These systems differ quite a bit depending on the manufacturer; I’m mostly familiar with Firestone.

Glad to be of help,
jkf


#15

Water based bonding adhesive is much easier to work with and is more forgiving than solvent based.


#16

Hi @jkf the roof is 30 feet long by 11.5 inches wide. That is why I decide to buy the 15X35 sheet of Firestone EPDM . My thinking was not to have any splices. I did contact a local roofing supply and they said they could help me out and also mentioned he had taken some classes from Firestone on how to put the EPDM down. I know I won’t get it perfect but I am hoping to not make some big mistakes. I did get one bid from a large roofer Company who specialize in low slope roofs I find out the price next week on there bid for Flintstone and Fibertite . I am sure it will be out of my price range . And I have already purchased the EPDM sheet that was 400 bucks. I am going to ask the roofing supply if they may know if a roofer I could pay for the day to help me. But I am really thinking if I go slow and learn a few tricks I can pull this off and have a decent roof. Thanks for all the information this really helps me. I am sure I will have more questions for You.


#17


I ran into this today and thought of you. Good luck. Without removing some of that stucco your roof Will never be right is my two cents. This may be one of those pay now or pay later situations.


#18

Yes thanks I have been watching those videos too.
So your thoughts are to remove the stucco to put the flashing in the wall behind the paper as oppose to a termination bar ? then re stucco the wall ?


#19

Yes thanks for that ! I will definitely buy the water based


#20

You don’t want to cut into your stucco if you can help it.

I am so glad we don’t have much stucco around here.