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I have a house with an inside 90 degree area which has a concrete patio. Over the patio (13′ x 18″) I would like to build a sunscreen with 2 4×4 posts, a header, and joists spaced at 12″ O.C. that would butt into the fascia/fly rafter on the one end. Does anyone know if a ledger can be attached to a fly rafter (overhang) on the existing nearly flat roof to support the joists? If so, any ideas on attaching them to avoid or conceal joist hangers.
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Replies
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Dan
How about four posts, and a completely independent arbor? Is there some reason why you can't set another two at the house side?
IMHO, the arbor should be a detail in itself. I wouldn't want it scabbed onto the fascia, but would want to see some separation from it and the house. You'll be terminating the screen on the open side with some kind of cantilever, and perhaps a second layer on top of the joist, made from more delicate material to actually provide the shade. Me thinks this would look nice all the way around.
nathan
*With that big of an arbor, you might also think about beefing up the posts. Not necessarily for the structure, but for the eye. Don't squoink out on the framing. It sounds like you are planning on a pretty sizable span with alot of wood going up there. Size everything properly so it holds its shape and looks good too. Best of luck.
*Thank you for your response. I would actually prefer to make the arbor completely independent, but at 13x18 I have yet to come up with an eye pleasing method for maintaining stability. This would be very top heavy and would need to be braced to stop it from racking or just collapsing. The only method for anchoring I have come up with is setting the posts in concrete and I have repaired many fence post that were not to old that rotted when anchored in concrete. Any other suggestions for stability would be appreciated.
*post bases, two members working together, one in tension and the other in compression to hold the post rigid. They really work well. You can always wrap the column base with wood, or even have a stone mason wrap with granite...http://www.strongtie.com/fr_architect.htmlclick visual selection guide, click caps and bases, click third base from top on right hand side. This is a structural base for your app.go to the post below for a view of a bronze post base with bronze through bolts and nuts. This base is 3/16" thick, almost seven feet long. About sixty dollars per for strap, bolts and nuts.
*this one is uncompressed.
*Thank you for your response. I looked up the strong tie base but the specifications state that the structure must be supported at the top. This structure is to be free standing. It would not be tied into the house. Any further ideas would be helpful.
*For whatever it's worth, here a 'pole structure' that was completed recently and may be one alternative to what you have in mind.(But this one is far removed from Nathan's furniture grade outdoor structure.)It's a freestanding shade arbor with a roof area of 28x12' supported on six 6x6 locust posts, each sunk 3 feet and filled with dry mix concrete.We opted against the bracing for the time being to observe it during heavy weather.So far, it is rock solid.Overhead structure is white oak 2x8 headers, 2x6 rafters and lattice is 1x3 red oak.None of the wood is pressure treated and is all native species to our area in southwest Virginia. They were all rough hewn at a local mill to true dimensions.Wyesteria on the left, which started wrestling the white oak fence out of the ground and twisting it apart, will be trained onto the structure for shade in the summer.The floor will be red paver bricks to match the house.The brick base will be sloped to drain water away from the basement wall.
*Beautiful. That is exactly what I had in mind. Forgive me if this is a dumb question, most of my carpentry experience was additions and remodeling, could you clarify dry mix concrete and how it is best used. In order to accomplish setting the posts I will have to break out sections of an existing concrete slab and auger holes to minimum 42" deep. What would be an appropriate hole size to accomplish the concrete and a 6 x 6 post. In addition, let me say that I have subscribed to Fine Homebuilding since my first foreman and mentor suggested it seven years ago. This is the first time I have used this site and everyone has been extremely helpful. Thank you to everyone who responded.
*Hi, Dan -I hired a pole barn builder (who is also a FH subscriber) who has a working relationship with the local mill and the means to haul the very heavy hardwood lumber. After coming up with a rough design and contemplating tackling the project solo, I wised up and hooked up with these guys. (Much to my wife's relief.)The 14' locust posts each weighed 300-lbs+ and it took three guys to steady and center each one in the hole and tamp the earth around.Mine is a embedded pole structure, and dumping in dry mix into the hole and letting the ground moisture take care of the rest is very common practice in our area for fences, etc. Each hole has four bags of dry mix (160 lbs total) You will find them as ready mixes in 40-lb bags. (I think Sackcrete was used.)Your area may require some sort of poured footing and anchoring system.But it being an open structure witout a load bearing roof (snow) may exempt it from being scrutinized by the officials, especially if it not attached to the house.Hole is dug, some of the mix poured in, then the pole is stood up and the rest poured around it. Earth is tamped in above the mix.After a day or so, it is rock solid.Our area requires 30" with a 8" footing base.We went 36" deep.Ours is an oversized garden structure, so to speak, but to me it is a shade house, as the pole barn builder calls it. The person who built ours has erected a similar one at a local garden center.One thing I failed to mention, and this is another coincidence....There used to be a concrete patio at this site !It had real bad settlement cracks from problems previous owners had caused by a broken gutter drainage pipe that was underdeath the slab.First thing I did when we moved in was to bypass the gutter drain line and demolish the concrete patio to investigate and dry out the sub soil that had suffered many years of saturation during rainiy season.I did it with a sledge hammer and a rented electric Bosch jackhammer....A rented jackhammer would be handy for your project if the pad is more then 9 - 10" thick. Otherwise a sledgehammer and goggles, gloves will do the trick.Let me know if you want more specifics.
*Thanks for all your help. Actually on the one I am doing, the patio is going to stay so I only have to remove enough concrete to auger the post holes. The frost line here is 42" so I shouldn't have a problem with stability. Thanks once again especially for forwarding the picture.
*I wish we had kept the concrete patio.Pouring another slab was considered as it was the best choice for us to protect that side of the basement against moisture.As for the post holes, they were hand dug because bringining in their truck mounted auger was impractical. But they had the holes dug fairly quickly. If you can operate an auger at your location, then good for you.Have fun with your project, especially with designing the end cuts for the rafters.
*OK, homeowner can not live with four posts. I can put two posts on the far end away from the house and support the other end off of the flat roof. I have never built off an existing roof. I was thinking of laying a 2x on an extra sheet of membrane over the existing roof to support this end of the structure. But what about fastening? #1 I will only be able to fasten to one rafter/joist. #2 other than loading up the bolt locations with roofing tar, how to I prevent leaks. Any suggestions would be appreciated.
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I have a house with an inside 90 degree area which has a concrete patio. Over the patio (13' x 18") I would like to build a sunscreen with 2 4x4 posts, a header, and joists spaced at 12" O.C. that would butt into the fascia/fly rafter on the one end. Does anyone know if a ledger can be attached to a fly rafter (overhang) on the existing nearly flat roof to support the joists? If so, any ideas on attaching them to avoid or conceal joist hangers.