[pwd77]

I'm thinking of a free-standing deck cover so to simplify the job. My main concern is supporting the deck laterally, which the ledger would normally do.

Are there acceptable methods to follow? Its easy to find info on decks, but covers less so.

I want to avoid the traditional clunky pergola style, as the multiple layers of ledgers will reduce my headspace, which is already low *8'), and make something more like a second deck with headers and joists. Once I make the frame, I decide what works best for a cover.

It will not be heavy, so I was planning to use 2x6, or even 2x4 framing. The side view shown here has a header notched into posts, which are attached to the deck either on top or to the sub-structure (there is a beam down the middle).

Another idea would be to notch the header and joists to fit together, which would weaken the header, but give 5-1/2 less obstruction of the view. Probably not worth the trouble.

So, are 2x4's too weak?
What will give adequate lateral support?
(I would like to avoid 45-degree "arms" at each post)



Thanks!

[21boat]

PWD77

My neighbor tried this and invited me over. I'm 6'2+ I felt as if I was going to Bang my head.

It lasted 2 years then he ripped it down and went On the roof not under it.

I think you be best served by either getting an awning you can crank out, or the cheaper ones you clip onto the Fascia board under gutter and stretch it out to the end of the deck

Sorry this looks like a cluster that will provide partial shade but will make the deck feel smaller and cramped. If you are bent on Not tyeing ying into the roof I would move that 6x6 a tad in front of the gutter and cut it off about a foot or so above the roof line. Now you can run your header off that and it will be above the roof line.

When you lay this out the finish side view would be what you have there but above the roof and back over the roof a foot or so. It will be above the roof line and yet give you the illusion that its tied into the existing roof because of it having a slope also and it will seem like its part of the house roof system.

[pwd77]

thanks 21

this is great info, and that's a great idea to build it high rather than low

any thoughts on what size lumber I can get away with? I'd like to use 4x4 posts and 2x4 or 2x6 lumber if possible, with 1x2 slats parallel to the house, angled about 30 degrees off perpendicular, about 1.5" apart to keep sun out and airflow and daylight in.







looks like I cannot rep you again until someone else gets some of my hard-earned reps

[21boat]

Pwd77 knowing the actual size of the deck would be a good start here.

1. Need deck size Width and length
2. What's the size of the existing floor joist?
3. Will new 4x4 be bolted to joist band or run through deck to ground and bolted?
4. What's the clear span on that joists if the new 4x4 is bolted only and not run to the ground?

I realize this is not a heavy supporting structure but time sags things if not supported well. On a side note does it snow where you are and how much in a snowstorm? Reason I ask is the clearance from the existing roof to the new cantilevered rafter over the gutter and roof. See my point. Don't want to cause a "Dam" in that area. Need buffer for heavy snow not to mention cleaning a gutter out...

[pwd77]

the deck is 27' wide (along the house) and 12' deep. The joists are 2x6 16" oc, and there is a substantial beam (two 2x6 plus posts) down the middle for extra support.

My thought was to bolt the outer posts to the beam, and the inner posts to the joists, with necessary support added.

Why only 8' deep on the cover? My goal is to have a fair bit of shade to sit in and shade the side of the house to keep it a bit cooler in the summer since that side faces south. I also would like to limit the lumber so I reduce the load on the existing deck.

thanks

[21boat]

The 27' is the barrier here to overcome because of the "clear span"

One way to help solve that problem would be to change up the railings 4x4 heights (27') side and replace some of them with Long 4x4s to get the height and break up that clear span.

This would bring the rafters over the whole top of the deck. Now before you panic those rafters would not have to be covered to the 12' end with the 1x2 slats. Theses slats could could be stopped half way out from the house.

If this is acceptable the other hurdle is the clear span close to the house. That could be the deal breaker here for you. The best way to do that is also add 4x4(s) from a concrete pad under the deck and bolt it to a joist or a cross scab between joist. Of course you have post in the deck. Maybe a wet bar Incorporated into them will work.. any how that's where you are at for supporting the cantilever roof other then getting into the house fascia and roof

[pwd77]

again some good ideas, 21, thanks

I was already resigned to posts in the deck to accommodate the 27' span. Running the joists all the way across the deck would add a lot of shade and not too much extra cost or work. A few posts near the house does not bother me.

Last question: do you suppose the 2x6 band, header, and 4x4 posts-bolted-to-deck will offer enough lateral support to keep it from collapsing sideways or forwards?

I am used to relying on a ledger bolted to the house to anchor things, and do not have a feel for how much lateral support one has without it.

[21boat]

Sorry Pwd77 Got side tracked

The laterial support/shear would be there when you run the rafters not to mention the 1x2s crossing the rafters

The 4x4 posts by the house needs to sit on it own footer/pad then you can bring it up through the floor and side bolt it to a joist. I don't know your codes there or your snow loads or the clear span.

In light of that I double up the 2x6 header leaving more head room if clear span is 8' between post. Double 2x8 header if 12' clear span is warranted

[pwd77]

Thanks 21boat

I found information that suggests that 45-degree braces may be necessary on each post for a free-standing structure.

Unfortunately a footer for the posts near the house would be very inconvenient, as the frost line is about 42" down. Thus I would like to just tie into the existing deck close (18") to the house.

As I see it, the ledger is not really taking its share of the load due to the beam running down the middle at 6' out; this beam is actually taking most of the deck load according to my calculations. I figure if I block in neighboring joists and sister up the supporting joist, the posts should have an adequate foundation. Of course, I am always open to informed opinion on this :D

[21boat]

pwd77 Don't know why you would ever need angel braces for this.

The only thing that can have shear or lateral stress is the 4x4 being undersized or not enough of them for spans. The roofs square crossing of rafters and 1bys there's no way you can wrack the roof.

So where are theses angle braces going?



maybe we crossed wires here. I thought we agreed you were going to run the rafters out to the end (12) side and partially cove them for shade diff. If so how is it a free standing structure... We have 4 sides of tie ins.

[pwd77]

Yeah, I suspect you are thinking in the horizontal plane, and I am thinking in the vertical. By freestanding meaning not bolted to the house. Still, there will not be a lot of lateral support from bolting to the deck substructure.. :confused:

This is what I am referring to:
Attachment 31237
If all the posts were through the deck into footings, there would be a lot of support. However, if I am effectively putting them on top of the deck (well, bolting them to the sub-structure) I would be concerned that it could tip forward.

Perhaps the anti-racking action of bolting to the deck joists and upper header and band is enough... :confused:

[21boat]

The only way it could tip forward is RIPs out the bolts. By the house added post.

Need to add the last part here in the drawing the deck/joist fill in all sides. So add the bottom to you drawing

Lets get back to you not wanting a footing. Another way to skin the cat is lay out the post so they end up in a joist bay corner. I see the joist are 2x6 ouch.. double up each side of the joist bays with 2x8 full length 12', notch out over beam below. Set new 4x4 in that doubled up joist bay corner. Now we have two doubled up joist holding up one post. Plus a wider area to bolt too.

[pwd77]

excellent idea

I was thinking along those lines, but making the double-up 2x8 is even better

thanks for all the help, its back to the drawing board now

[21boat]

PWd. I thought I had this in my last post. On those doubled up Joist do two adjacent joist and add a perpendicular 2x8 doubled between the Joist bay.

Now the 4x4 can go in one of those corners. The 15 1/2" cross piece will help transfer the load to the other doubled up joist so two 2 doubled up joist can carry the sway and loads. Keep the one doubled joist from yawing..

[pwd77]

Excellent, this is very do-able

Thanks

PD