Low sloped


#1

I need roofing recommendations for a 24’x32’ carport. It is very low sloped and almost flat with 5/8" plywood. I will be doing it myself. Have a rough idea from a previous roofing job on a part of my house. It seemed like it was a two ply system either torch down base sheet with self adhered cap sheet or self adhered bottom with torch down top with a 3" drip edge nailed down over the first ply.

Is one combo a preferred method over the other?

It seemed like they used an adhesive they called “brie patch”, probably a generic description, to add on top and underneath the drip edge.

Is this necessary for an added lock tight seal at the working edges?

I live in a very hot and sunny area, tropical with a good amount of rain so the intall needs to be done right. I am looking at a two ply self adhered system for $1200 but I need to find out if this will be comparable, in the sealing capabilities, as the torch down system for a low slope. These are the two types that I am looking at. I also noticed there’s quite a bit of talk on this forum about single ply too.

Could someone shed more light on these options? Thanks


#2

I like both systems. Self-adhere is alot easier, it doesn’t take as much experience as torch down.

Why do you think they mixed the systems?


#3

I am kinda vague on their process but low and behold, the head roofer called me late last nite to let me know the new construction co. he’s working for.

Even though he said he will work with me to roof the carport, I will still search for info in case not. He said the previous job was a nailed down base torch applied followed by a peel and stick cap sheet.

Mentioned to him, I was considering a peel and stick two ply system. He said it will not last as long. He didn’t explain if his mix match technique was proven better than a 2x peel and stick or he meant because I was planning to do it myself, but his mix and match process gives me the impression of a more stronger adhered first ply ??? this part of hawaii is an unforgiving environment with the rain, salt and especially sun with terrific fluctuations of temp, humidity and elements daily.

The working ends of the previous roofing job on the house looks like a very well sealed effort that could last so I am trying to learn if a two ply peel and stick has that kind of layered adhesion between the drip edge at the working edge of a roof because it seems like an easier process but if that mixed process is worth it, then I will need to learn to install a nail down torch applied base the right way.

Any thoughts on this and on the right way of nail down/torch down base installation?


#4

There is no benefit to mixing the systems at all; it would also void any warranty/s. I don’t know why anyone would. If you’re doing it yourself don’t even consider a torch app, it takes way too much practice to do it right. Go with the peel and stick. Application instructions should be found on the web. Keep in mind that if your roof is under a 3/12 you will not have a manufacturer’s warranty. GAF Liberty or Certainteed Flintastic systems are what you want to look into.


#5

IMO I would never use peel and stick on any low slope that didnt have good run off.True it is probably the easiest for a DIYer,but I wouldnt use it on a completely flat surface.It wouldnt cost much just to get a roofer to do this small area.


#6

Being questionable for a roof without good run off makes sense.

Are torch down bases usually nailed down first?

That roofer called this first ply “bri patch”.

Anyone familiar with the terminology?

I have accomplished first timer projects by learning the ropes first but it’s true, working with fire and wood substrate doesn’t leave room for error. Need to research before I give up on the idea of doing a torched down install.


#7

Try Genflex,they have a new peel and stick TPO one ply system.It just about looks too easy,I have not tried this product but apparently its good,but costly.I think you can download install instructions there as well.I only heat-weld my TPO,but thats not really a DIYers option either.I would put down an ISO board first though…


#8

Being questionable for a roof without good run off makes sense.

True, which is why I said the manufacturer won’t warranty anything under a 3/12 pitch with peel and stick. Being that it’s a carport with no living space under it and you want a system you can DIY you should be ok. I haven’t seen a picture of your roof but if the pitch is of serious concern, tapered ISO board is a viable option to easily give you some more pitch.

**Are torch down bases usually nailed down first? **
Yes. You don’t want to use a torch on bare wood.

**That roofer called this first ply “bri patch”.

Anyone familiar with the terminology? **

Brie (spelling?) was a brand name torch applied system that I believe went out of business. The roofer was probably using the brand name to refer to a general torch mod bit application, same as a person wanting a tissue might ask for a “Kleenex”.

I have accomplished first timer projects by learning the ropes first but it’s true, working with fire and wood substrate doesn’t leave room for error. Need to research before I give up on the idea of doing a torched down install.

I would discourage a DIY torch application not only because it’s dangerous to run a torch but because it takes hours of practice just to learn to burn the sheets right, not to mention when and where to make cuts, etc. Just one of those things that requires practice is all.


#9

U.S. Intec was bought out by GAF a few years back.

SP4 was a great product.


#10

both systems will work fine but i prefer caps with a fire retardant material just to be safe
just make sure water wont run backwards cause no system will work for long then no matter how good you tie it in
http://www.texaseliteroofing.com


#11

**Are torch down bases usually nailed down first? **

I understand, the ones that are not nailed first has an underlying material that’s more fire retardant than the wood sheathing.

** Anyone familiar with the terminology? **

Thanks for clarifying.

from the project description, could we eloborate more on when and where to make cuts?


#12

technicaldatabase.fsbp.com/techn … gs/modbit/


#13

Right on, Thanks! Tar Monkey


#14

not too sure if he’s able to help me soon because of his schedule for the next three weeks but I talked to him a little bit this morning.

he said the previous job on the house was a nailed down #40 underlayment followed by 3" drip edge metal with smooth mini brie underneath it and an application of roofing primer on top of it. Then a “brie patch” cap sheet was torched down on top it.

he recommends to do the same for the carport. I am hoping he could break away to assist with this brie roof. I will research the ins and outs of this system even though.


#15

If y0u want to do a 2 layer ply modified bitumen with no experience, cover your deck with ice and watershield.
You can’t nailed down the base sheet,(first ply)

Peel and stick would be a better option for you, cause you got no insurance, and you’ll be doing a mess by overheating or underheating.

If you go peel and stick, it’s recommended that you put new plywood on entire deck and it has to be primed…


#16

Currently looking at nailing down a Malarkie brand non-modified fiberglass (515) base sheet followed by the same brand APP FR (161) torched down cap sheet. Will also be sandwiching drip edge metal with mini brie (under) and roofing primer (top). This could be an economical option that could last a long time if installed right and followed with coating after ten years.


#17

Lose the ‘mini-brie’. Just use a full mid-ply modified sheet. I would go with a modified nailable base sheet also, the fiberglass base is nothing more than slight fire resistance barrier, at least the mod base might actually help keep water out.

nailable base
mid ply
cap sheet

all mod bit. Your metal goes between the mid and the cap.


#18

three modified plies? Only the cap sheet torched down? sounds like will be totally waterproof with all three plies adhered as one to substrate when torched down, hmm.


#19

Doesn’t sound like you’re doing much research…

1 Nail the “nailable mod bit base sheet”

2 Torch apply the mod bit mid ply sheet

3 Install your flashings

4 Torch apply the mod bit granulated cap sheet


#20

I could be doing more reading. LOL, suppose to know the basic torch down systems by now, getting there. I called one supplier for Malarkey torch down product availability and the salesperson was trying to sell me a mop down surface sheet for my brie roof. Researched by googling 501/601 before going down there.