Patio Cover Plans

Started by rdevine16, December 06, 2016, 04:22:47 AM

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rdevine16

I am constructing a patio cover to attach to the side of my house. It's roughly 16x22. It will be attached by ledger board at the house and will span to about 13 feet were it will meet 3 6x6 posts. It will be attached to 2 4x6 beams that span the length of the 6x6. The remainder will overhang on the other side. The roof will be just corrugated metal. The beams are connected to the post with through bolts. The beam also sits in a notch within the post for added support.

My question is is the 4x6 enough? Or do I need to go with a few 2x8s and connect them together?

rdevine16

A little more detail, the rafters will be 2x6 boards spaced 16" apart.


Don_P

So, an 11' beam span carrying half of the 13' rafter span (the house ledger carries the other half of the rafter), plus the overhang (width?)... that tributary area times the combined dead load (the weight of the materials) + the live load (snow/wind).

Need the overhang width and the snow load but I believe that 4x6 is going to be too light.

rdevine16

This is located in Florida. No snow.

Still think I should increase the header?  If so what should I be using?

rdevine16



rdevine16

After your initial comment, I dont want to take any chances. What if I was to use 2 2x10s per spacing and carriage bolt them together?

Dave Sparks

No snow but a very decent wind load if you want to protect from damaging winds.
"we go where the power lines don't"

rdevine16

Would 2 2x10s on each side be better?

rdevine16

Here is what it looks like!



Don_P

Minimum live load for non snow is 20lbs pre square foot (for 90 mph wind load) + 10psf dead load= 30psf total
Area supported by the beam is 8.5' x 11'= 110.5 sf
110.5sf x 30psf=3315lbs

Section modulus required ~55"^3 ... a 4x6 is ~18"^3, you're seriously undersized
A double 2x10 in #2 SYP is a little light, if you can source the 2x10s in #1 or better it begins to look better.

Do not connect to the house fascia, hanging on nails into tails is a recipe for a collapse at that end. Either get the rafters on the wall or on the roof.


rdevine16

Don I plan to remove the fascia where the ledger will go and attach the ledger to the house rafters using 5 1/2 in lag bolts. The ledger will span the whole patio cover and be a 2x10

DaveOrr

At my cabin, I have notched the rafters to sit on top of the sill plate.
They are then attached to the existing roof rafters.
On the eve side they rest on 4"X8" laminated beams spanning 6 posts over 36'.

Dave's Arctic Cabin: www.anglersparadise.ca

MushCreek

When I built a similar roof in FL, the local code called for 1" of depth for each foot of span, in a double 2X. In other words, for 4', they would require a double 2X4, for 6', a double 2X6, etc. In your case, technically it would call for a double 2X11, if there were such a thing. They would have required a double 2X12 in your case. I have no idea what the rules are in your area. If required to have a permit and inspection, it's better to call them.
Jay

I'm not poor- I'm financially underpowered.

Don_P

Dave's detail is one correct way to do it. Lagging a ledger onto a rafter tail is not the way to go. Ledger to the wall, or set the rafters on top of the wall, or on top of the roof. The tails are designed to hold up, the tails, 2', that is all.


rdevine16

What's the methodology for attaching the porch rafters to the sill? You're notching them but after that are you using a special bracket

NathanS

Notch to sit them on top of the top plate. Same way current rafters sit on top. Probably way easier to do a ledger board with timberlok screws.

rdevine16

I'm a little confused on the method to connect the botched patio rafter to the sill

NathanS

One clarification, the board(s) that sit on top of the studs in a wall are a top, or double top plate. Sill would be at the bottom of the wall.

It's not botched cause you're asking the right questions. If you Google search ledger board and maybe look at Timberlok brand they will have some info that will help you out. Structurally on top the roof or On the top plate works but that is going to open a whole other can of worms installatoin -wise.


rdevine16

I found a few videos of a guy using Timberlok to attach the house rafter to the top plate. Will need to investigate mine more tomorrow. The wall is also concrete.

Were you referring to almost a toenail with a Timberlok screw?

NathanS

No... A ledger board is a 2x that gets attached to wall studs. You attach the board using ledgerbolts...structural screws. My guess is just that the different brands will have info on how to use them. Then, once your ledgerboard is installed you would use rafters hangers to attach the rafters to the ledger board.

Some general internet searches on how to install a porch roof may be helpful. Find homebuilding is a good site for info. Even lowes or home depot would have books on porch roofs that should be relatively code compliant.

Also a little more confusion Timberlok is by fastenmaster. They have a ledgerlok screw which should be for this application. It is hard to keep all the brands and names straight.


Don_P

Simpson does make top mount hangers for concrete that attach to the plate on the top of a concrete wall, hang over and are a joist hanger. That would be my preferred method to a ledger in an application with a concrete wall if possible. a palm nailer makes that job go easier if you have a compressor. I didn't have the palm nailer yesterday in a tight spot and drove nails by putting one end of a flat bar on the nail and hitting the bar with the hammer, there's usually a way if you can outsmart the inanimate objects (one boss told me that is actually our job  :D)


rdevine16

I have also found this image. Does Two H3 work as well? Hurricane ties?

https://www2.strongtie.com/graphics/highwind/HW_D32.gif

NathanS

Hurricane ties are for high wind that will turn your roof into a kite. They will not support the weight of rafters or joists hanging on them.

the first link for masonry hangers looks right but I've never used them. Don's eyes are better than mine - I didn't notice your house is made of block.