Question about roofing a covered patio

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24
Location
San Diego, CA
I have the structure for a covered patio which measures 17' x 12' is substantially complete. The structure is built with 2"x6"x12' stringers attached to the house with joist hangers on a 2"x8"x16' ledger secured with 3/8"x5" lag bolts sunk into the wall studs. Perpendicular to the stringers, which are set 24" o.c., is 1"x8" tongue & groove (T&G). The T&G will be covered with 1/2" plywood fastened to the stringers with 2 1/2" headed nails.

Next comes the roofing. But a question concerning the plywood nailing schedule. Would it be necessary or wise to nail the plywood to the T&G between the stringers using 1" roofing nails? Or, is the longer nails every 24" in the stringers sufficient?

The roofing material is rolled roofing over a layer of 30# felt. Since this is So. California, I don't have to worry about load and the Santa Ana winds are not a problem here. Rainfall is normally about 10" per year (last year we only got 3" all year).

Any suggestions or hints about laying rolled roofing? Is it as simple as starting at the roof edge and overlapping the material until you get to where the roof meets the house? Does the drip edge go under the felt? What is the overlap of the felt and the rolled roofing. Do you start your first course of felt using a 1/2 wide length of felt? What is the nailing schedule for the felt? Any suggestions would be appreciated.

By the way, I built a 2 1/2" fall or slope on the 12' side and a 3" fall in the 17' direction. A little bit too much, I think.
 
Robert,

i'm not a professional roofer, but I have help several people put roofs on before. Here are some answers....

Next comes the roofing. But a question concerning the plywood nailing schedule. Would it be necessary or wise to nail the plywood to the T&G between the stringers using 1" roofing nails? Or, is the longer nails every 24" in the stringers sufficient?

Longer nails every 24in on the 2x6s should be sufficient.


Any suggestions or hints about laying rolled roofing? Is it as simple as starting at the roof edge and overlapping the material until you get to where the roof meets the house? Does the drip edge go under the felt? What is the overlap of the felt and the rolled roofing. Do you start your first course of felt using a 1/2 wide length of felt? What is the nailing schedule for the felt? Any suggestions would be appreciated.

Start at the bottom going across the roof and then work your way up. Be sure to over lap each lower "row". Continue this right up to the house. Depending on how it meets the house and your siding, you may need to put metal flashing under your siding, but on top of your roll roofing. Nail it down and then tar over the nail heads.

The drip edge goes on top of the felt, but under the roofing.

The over lap of the felt on itself, itsn't very critical. Generally you could go a foot or two. Just be sure to felt the entire roof, before putting down the roll roofing.

The idea of the first course when using shingles and roll roofing aren't the same. with shingles you need to flip the first course upside down, and then lay a 2nd "first course" on top of them. The reason behind this, is to prevent water from getting to the sheeting from between the tabs. With roll roofing, there are no tabs like on traditional shingles, so just start with your first row, and continue up to the house.

For laying the felt, you don't need to waste nails. An electric staple gun is sufficient. just shoot the staples in as you go. All they do is hold the paper in place while you put the roofing down. The weight of the roofing will hold it to the sheeting.
-You could use an phenumatic stapler if you really wanted to, but thats is a bit over kill.

I hope this helps some.:wave:
 
robert,
if you feel the need for fastners between rafters i`d use screws instead of roofing nails, they`re less likely to work loose over time and puncture your roofing material.
you`ll need to determine your flashing schedule before you start roofing so you`re not playing catch-up over the asphalt.
sean covered everything else i can think of.
 
flashing schedule?

Thank you Sean for all the informatioin. That really helped. However, you indicated to start at the bottom and work to the house. How do you avoid ending up with a narrow strip against the house? How do you lay out or plan the rolled roofing?

Tod you mentioned a flashing schedule. Can you elaborate? Do you mean flashing between the house and the roof? Is that a right angle metal flashing about 3" wide on each leg? Is that attached with nails to the roof? What keeps the water from not leaking at the nail puncture? How is it attached to the house (stuccco)?

Thanks again guys.
 
robert,
the way flashing is usually retrofitted to stucco here in the sticks is to cut a saw kerf 2-4" above the roof into the stucco angled up at a 5º-10º angle and insert "z" flashing into the kerf, down the wall and onto the roof.
this flashing is generally bent on site using a siding brake and is adhered to the house using a butyl sealant and allowed to float on top of the roofing.
it`ll depend on the pitch of the roof what bends and reveals are needed.
do a search in marty`s birth of a shop thread i think he took pics when he flashed his dust collector/compressor shed.....
tod
 
I'm confused about the t and g. Is it on the underisde of the structure (ie the ceiling) Sean and Tod covered everything really.
 
Thank you Sean for all the informatioin. That really helped. However, you indicated to start at the bottom and work to the house. How do you avoid ending up with a narrow strip against the house? How do you lay out or plan the rolled roofing?

The usualy overlap is about 6in. Check the roofing that you are going with to see if it is English or Metic.(that is 36in or 39.something inches). If we assume that it is 39in (HomeDepot carries this size)and your roof is 17 feet from edge to the house.

17ft * 12in=204in.(total inches from edge to house),
39in - 6in=33in(of usable roofing after overlap)
206in / 33in=6.24 rolls of roofing to get from the edge to the house, with a 6in overlap.
.24in * 39in=9.36in is the width of the ".24" of a roll from above
9.36in + 6in= 15.36in is the approximate width of the last roll that butts up to the house including the 6in overlap of the previous full sheet.

so overall, you will need 7 rolls of 39in wide by 12feet long to cover this roof given a 6in overlap as you go up to the roof.

I guess i got off on a math tangent there, but the answer to your question is that you adjust the overlap so that you don't end up with a tiny strip at the top.

:eek:DISCLAIMER!!:eek: - Be sure to do the math yourself, I can't guarantee that my calculations are 100% accurate. :huh:



Is that attached with nails to the roof? What keeps the water from not leaking at the nail puncture?

Yes, the bottom of the flashing will sit on top of the roll roofing (this is done last after the roofing is down). It is attached to the roof with roofing nails through the metal flashing and into the roof. You seal the nail heads with tar/roofing cement. This will prevent a leak at the nail heads. Every so-many years you could check them to make sure they don't need more tar, as a preventive maintence.

Also as with any ashfault based roofing (roll or three tab), don't walk on it any more that neccessary. This will cause premature wear, as the tiny stones are dislodged as you walk on it.

I forgot to mention in my initial post, that you can install "rake edge" on the sides. It is similar to drip edge. It is installed on top of the felt paper (using roofing nails) and runs from the house down to the drip edge. It is not necessary for a porch. but is usually used on houses.
 
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