[Stubits]

I just discovered a relatively small leak in my asphalt roll flat roof. From what I can ascertain, it seems like there must be a break in the flashing around the house's main stack (3" cast iron), allowing a small amount of water to trickle in and run straight down the stack and into the attic. If necessary I can make my way up onto the roof tomorrow and take some photos (it's currently raining), but from previous visits to the roof I know that the flashing is not one of those preformed rubber or metal ones, rather, it looks as though some pliable metal (perhaps lead) was used and then coated with roofing cement.

So, how do I go about fixing this? The roof is in otherwise great shape.

Thanks!

[dawgsnkats]

The boot is probably lead. The flashing is probably coming loose. You can get some flashing cement and trowel around the base of the pipe boot. Make sure that the seal at top of the boot is secure with an adhesive based sealant. You can use this flashing grade adhesive for other spots that need touching up also.

Have a professional roofer look at your roof and give you an estimate. Most of the time, when flashings start giving, a new roof is needed. Even if you decide to hold off the new roof, at least the estimate will give you an idea of the budgeting you will need for the next roof.

Be aware of the new reflective roof membranes such as TPO or PVC. They give excellent tax breaks as well as energy efficiency. If your roof is large enough, study the possibility of solar panels as an addition.

Hope this answer helps.

[21boat]

I know that the flashing is not one of those preformed rubber or metal ones, rather, it looks as though some pliable metal (perhaps lead) was used and then coated with roofing cement

I doubt the flashing is bad. Its more then likely the old ptich is dried out. Remove old cracked pitch and re coat with new fibered roof pitch.

You could clean it all up and slip over a new rubber boot to flash it. Even then you will be nailing/screwing to the surface and pitching that under the metal flange and the outer edges.

So save the money and re pitch.

Your asphalt roof is a basically a seven year roof. Use rubber roof when you replace it and boot in then

This is a very common thing in my neck of the woods.

[Stubits]

21 Boat- Thanks so much. I will get up on the roof soon to figure this all out. I agree, I'll need a new roof sooner rather than later. We had quite a thread going sometime back regarding flat roofs. I hope you won't mind a couple more questions.

First, my roof is about 16'x45'. Now, I know you can get EPDM material in this size, but do you recommend this? From what I've read, this will weigh about 300-400 lbs. This seems like it would be VERY difficult to work with. Any thoughts?

Also, how do you handle protrusions, like skylights, vent pipes, etc?

Can I leave my current roof in place and just install foam board insulation on top of the current roof and then install the EPDM on top of that? Or is it better to tear off the existing roof?

I noticed that EPDM roofing comes in different thicknesses, 40 mil, 60 mil, 90 mil. Obviously the higher, the better, but which is standard? What do you recommend?

Finally, is this something that is DIY-able? Can it be done by one person or would I need help? How long should it take?

Thanks!

[dawgsnkats]

Stubits and 21 Boat. I doubt that the roof in question is a "pitch" roof. My bet, as with most residential applications, the roof is a APP or SBS modified system applied with asphalt in layers. Depending on what part of the country you are in, a modified roof should last at least 10 years if the roof has 3 layers which is basic. Most manufacturer's will provide a 20 year warranty on the modified roofs.

If Stubits is planning on installing himself, then EPDM is the way to go. The problem is knowing what is on the current roof. That is the reason I suggested asking a professional roofer for a QUOTE. They will be able to core sample and ascertain the best method for the new roof. Tearing off or recovering.

Flashing for all protrusions can be done using flashing tape made of EPDM. Most manufacturers will provide details on how to flash items on your roof.

Any place you can buy the material can also provide recovery board, insulation board and accessories. They usually have a boom truck to lift materials to the roof also.

.060 is the norm for EPDM in the south. . 045 for porches and non-occupied buildings. . 090 is for heavy duty and long term applications.

All three can be installed by mechanically fastening or fully adhering. The more sound method is fully adhering using bonding adhesive on polyiso or HD wood fiber board. Be sure to check local codes to see what is acceptable.

You are going to need at least a group of 4 people to pull this off. The weight isn't an issue so much as the width of the membrane and the speed of drying time of the adhesive.

The roof is around 8 squares. You will probably need to buy a 5 or 10 sq roll minimum. What type of parapet walls do you have around the roof? What is the egress for the water? Do you have roof drains, gutters and downspouts with a gravel stop flashing or do you have scuppers with leaderheads and downspouts? All of these questions need to be answered to correctly assess whether this is a DIY project or not.

Typically, 8 sq of 060 EPDM fully adhered on 2" of ISO, tearing off an existing modified roof with no asbestos abatement, flashing all protrusions and installing new 24 ga sheet metal flashing and gutters/DS or Scuppers/DS will run about $1000 per square. This should also come with at least a 10 year warranty.

[Stubits]

Thanks so much for the thoughtful response, it was really helpful to put things into perspective. I've read up on this topic a bit before and 21 Boat gave me loads of info. I think I've got a while before my roof needs replacing, but I want to make sure I am ready to go when it does. I hope you won't be bothered by a couple of additional questions.

First, to answer your questions. We do have parapet walls, made of brick, around most of the roof. They are rather low. The parapets have a metal cap on them. Also, the entire roof drains into a 10' long gutter with a downspout. I am including a picture, which although it doesn't show the roof fantastically well, does give you a feel for the gutter and the parapets. Also, just FYI, we have 3 pipes protruding through the roof, 2 are 2" and 1 is 3". We also have 1 skylight (although I would like to add 1 more) and an access hatch. There are no other protrusions.

Second, good idea on getting a quote. Truth be told, I am not sure what type of roof I have. It looks like very long strips of 3' wide asphalt shingles, but I don't know.

Third, I see that some places you can purchase EPDM in a variety of lengths and widths, but usually it comes in 10' widths and in varying lengths. Obviously being able to cover the hole roof in one single membrane would be great, but it seems like it would be difficult to work with and also difficult to work around protrusions and stuff. What do you think, better to go with one single piece or with the 10' widths? I would also imagine that if I used the 10' sections I might not need so much help?

Fourth, can I increase the amount of iso for increased r-value?

Fifth, in your breakdown, you mentioned new sheet metal flashing. Given that most protrusions are handled with EPDM, what sorts of flashing are necessary. Along those lines, is it possible to purchase the parapet cap flashing, or will I need to have that custom made?

Sixth, thanks so much for the estimate you gave above, very, very helpful. Based of that estimate, what do you think the materials alone would cost? Just a rough estimate.

Finally, seems like you've got a bit of experience here. Currently our attic remains unvented. Fortunately it's an old home, so there's like of ways for air to escape. What do you recommend?

[dawgsnkats]

Stubits, the reason I asked about the parapet walls is to ensure you knew that the material needed for the EPDM system will need to be measured for the field, which I think you quoted as 16' x 45', and also the area of the parapet wall and the top of the parapet wall. When installing EPDM, you need to adhere up and over the parapet wall, then top the wall with metal coping/cap.

You really need a quote for this roof. The core sample is needed. I would ask for quoting EPDM as well as TPO. TPO is not a DIY membrane since it takes a specific welder to install. Great for energy efficiency though.

10' width is the norm. The length is usually 50 to 100 feet. Stick with the 10 x 100 and have someone help you cut the membrane. Protrusions aren't hard. When you roll out the material, the cuts will seem natural. Remember, the membrane around the pipes will be further protected with pipe boots.

Your roof is a modified cap sheet system applied with asphalt. Probably two layers of base sheet and the granular sheet on top.

Increasing the ISO will help in the R value. Don't overdo it. If you have insulation on the floor of your attic, then you won't need much on the roof. If you plan on using only ISO, then use a base of R 24-R 30.

Sheet metal flashing includes metal coping/cap and the drip edge/gravel stop that takes water from the roof edge and dumps into the gutter. The metal coping may need to be replaced. If so, any sheet metal shop can fabricate all the sheet metal flashing for you.

The materials alone will cost around 400-500 per square-including r24 Iso and new metal on parapet. The price for your roof will be heavy labor, since removal is included with disposal.

What type of attic space do you have? Crawl space or walking height? Can you access it readily? If so, I suggest a power ventilator with a humidistat feature. This will turn on at a certain temp or humidity level and turn off at acceptable ranges. If you can't access it easy, then look at turbines.

PLEASE UNDERSTAND that membrane systems fail at seams and flashing. Therfore, the less seams and flashing, the less chance of failure. Use the largest membrane possible and minimize seams. There is also some new self adhering EPDM that may be easier for you to work with.

[21boat]

Can I leave my current roof in place and just install foam board insulation on top of the current roof and then install the EPDM on top of that? Or is it better to tear off the existing roof?

Yes you can rubber over a single mineral roll roof. There are different length cap screwes just for that reason. But all this will depend on how many roofs are on it now and what the codes are there.

At times we install rubber over standing seam roofs and install the felt board between the seams.

Running the roof up over the top of the parrot pit wall is the best way. Although many times we need to use a "termination bar" to roll up a façade.

You may be able to re use the white flashing cap there if you can remove it carefully. If not new alumi cap needs to be folded and installed.

I don't think it was mentioned here and I mentioned it before, install the rubber roof and make sure it falls over the roofs edge about an 1" or so.

When you install the drip edge and nail it down the roofs edge is protected in case the rubber strip which covers that drip edge fails or the SPM seal fails.

[dawgsnkats]

Stubits, if you decide to roof over the current roof. Be sure to use a layer of HD fiber board as your base layer on top of the modified roof. You can save money by using EPS instead of ISO as an insulation.

If you go with aluminum coping, be sure to use a thick gauge. 24 ga is the metal standard.