What is the best value material for a 2/12 pitched roof?

What is the best value (price, compared to life, compared to ease of installation) material to go on top of shingle, on a 2/12 pitched roof, that is also comparatively easy for a handy-man-homeowner to install? Considering, in order of importance, price vs expected life-time vs ease of installation. I’ve been reading and reading but haven’t found a good answer. Shingle is way too tedious for one person with limited time and the roof is too flat anyway. torch-down is too dangerous. EPDM isn’t supposed to be installed over shingle. There is “liquid roofing” but not much info on price per 100 sq.ft., PVC which I don’t know much about, and single-ply self adhesive which I can’t find prices on.

Add a layer of fiberboard down before the EPDM.

I agree with RoofCheck. Put down some 1/2’’ recovery board with a .045 Reinforced EPDM mechanically attached over it, & termbar the edges. I do it all the time at $200 a square labor & materials & can still make dough! : )

  1. is fiberboard and recovery board the same thing?
  2. What nails do you recommend to fasten the fiberboard?
  3. What nails to you recommend to fasten the EPDM down with?
  4. What does “termbar the edges” mean? There’s some kind of glue or tar that is used on the overlap area right?
  5. I’m in Florida and 3/5ths of the house is in direct sun. Do you still have the same recommendations?
  6. What’s the typical life-time of EPDM in my environment assuming it is installed correctly?
  7. What’s the tyical cost of EPDM per 100ft^2?
  8. What’s the tyical cost of fiberboard per 100ft^2?
  9. Is EPDM sold in white?

Not familar with the term recovery board. Fiber board= High density insulation its what we use. You should use screws and 3 inch washer plates NO NAILS. We dont mechanically fasten I use a latex adhesive which is very easy to work with. Termbar=termination bar is an option to fastening the rubber around the perimeter at the fascia board. Or you can use a drip edge and cover strip. Direct sun shouldn’t hurt but will absorb a lot of heat. If that is a concern you can use white rubber the cost is roughly double. 0.45 rubber aprox .50 sq ft. Fiber board 7-11 $ per 4x8 sheat. Seams should be secured with seam tape and primer. EPDM rubber roofing can last for 30 years if done correctly. I average about $300 per square in my area.

what about rolled roofing? (I’d post a link to some 3x36’ $35 stuff at lowes/home depot but I can’t)
That’s even cheaper than EPDM correct since it’s ~$35 per 100ft^2? could I use rolled roofing right over shingle or maybe with some sort of underlayment?

Roll roofing eh? Just leave it the way it is then. No need to cover it that’s what you want to use.

Or use EPDM and go for several years of use.

If you are willing to high someone to do the work; then what the guys are telling you above might be your best route.

If you are actually trying to do it yourself cost vs ease of installation? All you need is a hammer, flat bar, chalk line, etc (simple tools). Buy you 3-tab at your local hardware.

Trying to learn the products above vs actually putting it on yourself will be much more difficult…and you will probably pay a higher cost for the material. You cannot get EPDM in a 1/3 bundle (3-tab); you have to buy a roll or 1/2 roll.

I’m just trying to find any good reason NOT to use rolled roofing at this point. It strongly looks like the best choice for the characteristics I’m after.

  • It’s extremely cheap, essentially made of the same stuff as common asphalt shingles (but thinner),

  • seems to be really easy to install unlike common asphalt shingle which is very tedious. (My roof pitch is too flat anyway.)

  • It only lasts 5-8 years from what I hear but who cares, it’s so cheap and simple to install that I don’t mind

  • It already comes in white so I don’t have to paint it.

  • I can buy it locally

The cons are:

  • It looks like s***

  • only lasts 5-8 years

Am I missing anything?

I wonder what WHITE EPDM costs, with the boards, in material per 100ft^2? I bet it’s at least 4x the $35 that rolled roofing costs. However many more times the costs is, it better last that much more. So if it’s 6x as expensive, it better last 6x as long, or else it has a lower value.

For a diy I would recomend going with Gaf Liberty, or Certanteed Flintlastic. They are very easy to install, however I would not recomend using them over existing shingles (don’t recomend that for anything other than single ply). I wouldn’t even expect 5-8 years out of the $35 home depot roll roofing installed over shingles.

To say EPDM is six times better than 90#(roll roofing) is an understatement. It may not “last” six times longer, but it’s so much more reliable. And it may last six times as long.

If you just do a one ply app of 90#, you’d be looking at 5-8 years under ideal conditions, and assume you have a couple small leaks before then. We put it down a couple times in the 90’s in a two ply fashion and got about 7-10 reliable years out of them.

[offtopic]For a diy I would recomend going with Gaf Liberty, or Certanteed Flintlastic. They are very easy to install, however I would not recomend using them over existing shingles (don’t recomend that for anything other than single ply). I wouldn’t even expect 5-8 years out of the $35 home depot roll roofing installed over shingles.[/offtopic]

This ^^

Tear off the shingles, don’t be lazy.

Putting it on top of shingles will ensure it fails within 6 months to a years.

Why? What specifically will cause it to fail prematurely?

It’s not a flat smooth surface. It doesn’t last very long on low pitch roofs anyway. Why shorten that?
Even EPDM won’t last too long directly on top of the shingles.

[quote=“tinner666”]It’s not a flat smooth surface. It doesn’t last very long on low pitch roofs anyway. Why shorten that?
Even EPDM won’t last too long directly on top of the shingles.[/quote]

ok. What specifically is happening to the rolled roofing layer when it’s on top of shingle that causes it’s life to be reduced?

Many things can contribute to a shorter material life span in regards to going over existing roofing. Things like:

  1. Possible heat or gas build up (if using low slope material)
  2. Possible trapped moisture (particularly true if the area in question has been actively leaking)
  3. Possible popping nails. Sometimes nails back out of wood and will puncture the top layer of roof material.

Also when you tear off down to bare wood deck you can:

  1. Assess the decking for rot/water damage and replace any needed wood
  2. Install new Ice and Water barrier to appropriate areas
  3. Install new under-layment to appropriate areas
  4. Inspect and install new flashings

It’s much better practice than re-covers; to the point where we don’t do them. There is a reason why Manufacturer’s won’t
allow their better Warranties when a re-cover is involved.

Tear it off, any material you will pick after that will have 1/2 a chance at lasting more then 5 years.

Fiberboard over shingles? That’s a piss poor installation if you ask me.

If you want cheap just shingle over what you have now, expect to do it again in 5 years or so.

Tear it off, put down a coverboard (fiberboard) and put a single ply on.

Tear it off, put Self adhered modified on.

Tear it off, put metal on.

Tear it off, put shingles on. (I personally wouldn’t do this on a 2/12)

[quote=“1985gt”]Tear it off, any material you will pick after that will have 1/2 a chance at lasting more then 5 years.

Fiberboard over shingles? That’s a piss poor installation if you ask me.
/quote]

I agree and we wouldn’t do it but thats what OP asked, over shingles.

For the record, we don’t cover anything, but if someone asked and insisted on a cover I would recommend exactly what I recommended, but we wouldn’t do it. Rubber over granules is a terrible idea. Adding fiberboard is the bare minimum.[/quote]

Do I have to put down an underlayment like #15lb felt after I tear off the old roof before putting on rolled roofing?