Porch roof build

Hey everyone! First off, I searched for these details for a bit (not extensively), so I apologize if there is an existing thread that covers my questions. That said, I'm new here, although I have tapped into the collective wisdom on these DIY forums before. Thanks for that!
Moving on... I am building a porch roof for my mom. I have some framing experience, but not a lot. I have done roofing and concrete before, but certainly am no pro regarding either. I have been pouring over codes and span tables and all of that stuff. Where I am, inspection isn't relevant. I am struggling a bit with definitive answers for my building plans. Snow load isn't much here (don't know exactly, but will confirm that), but we do get a lot of rain and wind. I like to lean a little on the overdo instead of underdo side, but do have budget limitations. I'm planning on using two 8"x8"x8' posts (undecided wood, but nothing too fancy), supporting a tripled 2"x12" beam - spanning 12'10", and 2"x8"x16' rafters (maybe longer if needed for attaining appropriate pitch) spanning about 10'. I'm planning on tying into existing roof and house frame, bearing load on exterior wall - not excited to add more posts to bear weight unless it's just way more practical than tying in. I likely will build a knee wall (to get enough pitch) on top of the exterior wall (obviously removing some roofing elements) and attaching new rafters to existing rafters. I'm still looking over loads for concrete footings, but looking at forming up some 18"x18" concrete pads (maybe sonotubes... what size if so?), going down 2'-3' with a good sized (24" bell?) and a piece of rebar stuck in the middle. Still deciding if I want to set post anchors in concrete or use some redheads once the concrete has cured (input here appreciated).
Assuming this, so far, doesn't make any of you pros facepalm... I am concerned about having to bring new porch roof up too high on existing roof (to get adequate pitch) and looking weird, as I'm already throwing another angle with the different pitch on porch roof than the existing roof over house. I have been mulling around notching the posts for the beam to rest on to consolidate that outer edge and increase potential pitch. It seems to be a little more secure to me that way as well. I know there is the option of doing a gabled roof, but I'm trying to keep the geometry down here, lol.
Nothing is set in stone at this point, but that is my plan, so far. Please let me know if you see any major issue or potential pitfalls. Also, please don't tell me to consult with a structural engineer or an architect... if I wanted to go that route, I wouldn't be posting here.
Thanks in advance!

-Thomas

 

Welcome to the forums! For your thousand words, can we have at least one picture? It certainly would help us develop in our minds what you are planning. http://www.doityourself.com/forum/el...your-post.html

 

I'm putting it over the existing concrete slab, but not using it for support of the posts, hence the additional forms. I will have to remove roofing components as stated to add knee wall/seat on top of wall.

 

I just finished a DIY porch roof build, your spans and material selections seem reasonable from what I remember from the tables. I advise you do a search on the internet for the building codes and take a look, it will give you peace of mind I'm sure.

I set my roof supports on top of the concrete footings and bolted them down with brackets and anchor bolts. I believe this is better than setting the post in concrete where it will trap moisture and rot.

Your footings depth / diameter also sounds good but your building department will be able to tell you the standard for the area which changes with frost line and soil type.

Do you have the ability to get a permit? I have heard people complain about building inspectors but I never have an issue with mine. I just draw something up and they give it a review and inspect my work. I look at it as hiring an expert consultant, it's well worth the minor hassle of getting the permit. At the end of the day they want to make sure the structure is safe and won't cause future problem. I think the majority people bad mouthing inspectors are shady contractors who are cutting corners at the expense of their customers safety and quality to pad their profit.

Make sure you get the minimum roof pitch. All codes are in place to protect your safety or prevent premature failures. You can put whatever pitch you want but you will regret and pay for it later. Not to mention have issues selling the house in the future.

 

I think it's probably an even split between incompetent contractors and clueless diyers. As mentioned one of the main reasons for the permit/inspections is to make sure it's built to minimum code preventing many problems that can arise from shoddy work. It also eliminates any concern of the inspector showing up unannounced and shutting the job down. The fine for no permit is usually double the original fee not to mention they can make you tear down what you've already done
IMO the only downside to a permit is it might raise your tax bill.

 

Engineering shouldn't be required. California is strict on permits, but a patio cover doesn't require engineering in most cases. The drawing below shows what they want to see, review it and see if you have some questions.

There's mods here well versed in building stuff like this. All we need to do is choose appropriate sized lumber, footings and connectors.
For example the posts will set on stand-off bases, 1" or so above the footings.

 

As far as I can tell from what the city/county have online and talking to local builders, there's no way for me to even get a permit for a residential porch. The city and county both seem fairly incompetent in the building department anyway - and I prefer not to turn them on to this little project, having said all that. This porch has enough stupid in it with me already!
Thanks everyone for the input and the time involved. I am still deciding whether I want to anchor the brackets for the posts in the concrete when I pour, or bolt in after cure. Also planning on going above minimum pitch - rather overbuild than under build. About to order my lumber from the mill, so almost time to break ground! Thanks again for the input, again if anyone sees red flags please let me know. Have a good one!

 

Handyone - my problem now with drawing my plan is: In order to get my pitch and exact point of attachment to the house, I need to put the posts and beam in and then remove roofing to see exactly where my rafters will fall. Also if I need to build that knee wall to get adequate pitch. I'm hoping that when I get to that point of securing rafters they will be able to land right above the exterior wall and not need much more at all. If there's anyone here that can help me figure out the numbers here without going into Einstein's theory of relativity (just kidding) I would love the input. I can handle a little Pythagoras, but was hoping there was a short and sweet answer for this. Thanks again.

 

Sounds like the permit isn't required or they just let it slide. Even here, they don't require a lot of fancy drawings and such, they just want to see certain connection methods used and some other standard practices.

As far as the height, you don't have much. Here, we only need to slope to drain.
Hopefully some others will join in about the height issue, there's some options.

 

Thanks Handyone... the whole planning process I have had this nagging feeling that I might be overdoing the slope. It sure would be a lot easier to lag bolt a ledger to the wall studs and use hangers, but again, I like to err on the side of caution. Also hoping for some others' input as well.

 

The necessary pitch with your situation won't allow you to put any framing under the overhang. It is already at the 8' point and it would not allow sufficient height on the outer space as well as allowing proper pitch for drainage. With that said, building a gable type roof attachment would be the only way I can see you doing this. Proper support of the post and their bases has been covered. You will need to determine the width of the porch so you can also determine the pitch of the gables and how high it will go up on your roof.

 

I'm trying to avoid the gable roof, which is why I am explaining tying into the roof and bearing load on the exterior wall. Have any experience in doing this?
Also, thanks for your input as well. I was hoping there was some simple trick I missed to allow a ledger, but I guess not. Oh well... Also, thanks for encouragement, I'll get some numbers crunched and determine length.

 

I could almost guess, but post the height of the exterior wall. Also post the distance you want your posts and beam out from the wall.

I like the gable end approach also, it would dress up the house nicely. If it's only the angles that concern you, that you can get help with. You have to tie into the roof and framing one way or another, the gable roof will look like it belongs there.
The other nice thing about a gable roof is that the area above the existing roof will not be structural, just what we call out here a California fill.

 

Yes, I'm scared of the angles, valleys, tying into existing shingles, etc. I have done roofing over existing gable roof, but never tackled framing one in. I have seen differing schools of thought on going over shingles vs stripping, also adding to confusion. It's not out of the question to go gable, but it just seems so much more simple to keep things square instead of opening up Pandora's triangle . I agree that it would look much nicer and that I have to tie in either way. I'm going to revisit this option...

 

I don't have an exact number for exterior wall, but I'm guessing 8' and a little change from where the rafter tails meet the wall. 8' ceilings in the house. I'll get that tomorrow when I'm setting forms. Distance from the wall to the posts is 8'11", but the span from wall to beam would be 9'3" with the rough plan I have going at the moment. Varying due to the beam sitting in notch on outside edge of posts. (Using dimensions: 4"x12"x16' for the beam - thinking about having this milled, instead of tripling 2"x12"s.

 

I stand corrected: 7' 2 3/4" or 86 3/4" where wall meets *soffit, not rafter tails.
And the run... 9'8" or 115" from wall to outside of post/beam. I hope I'm the only one scratching my head trying to figure out where rafters will land if I do, for example, 4:12 or 6:12 slope... and I thought I wouldn't never use much math in "real life" lol!

 

Here's a shot of where the wall meets the soffit.

 

Not going gable because my mom prefers not to. She's the homeowner here, so going with her preference. Anyone have any useful knowledge on my op? Again, looking for specifics on knee wall for the most part. Thanks.

 

You plan on extending the rafters past this knee wall to grab the pitch of the roof where it will sit further up? Or some kind of pitch gutter system behind this wall?

 

I plan on running rafters up where they grab the pitch of the roof. I'm not able to find much on limits of extension on this side. I have seen 24" or 1/3 overhang limitations on the other side. I'd like to attach to existing rafter at the point where the rafters meet the pitch. Does this sound far out there?

 

To me you are going to have to be a bit high on the yard side post or you will be blocking some view.(widow etc.)Which would put you high on the roof side to get a good pitch. Could put another knee wall so to speak if it was to long depending on load.The higher up the better the pitch.

 

That's a great idea, in case I have too much rafter hanging over the knee wall...

 

Also, I would need to land on a wall plate for this second knee wall or somehow cantilever the load point somewhere besides the trusses, right?

 

Hi Tom, I would do about midway if long and make as light as possible.Just enough to disperse the weight of a man walking around there.I take it that there is not much snow where you are.

 

Hi! Not much snow load to be worried about, but I still prefer to overbuild. With weather in 2015... who knows what the future forecast looks like... lol.

 

You need 3 strong carrying points for that roof imo.You will have two.Ground post and side wall. Third would be near end of rafters toward ridge.Any more then that is fine. Consider ice and water shield for the new roof covered completely. Good luck.

 

Thanks guyold. I got out my thinking cap today after I set up the forms for the posts. My rafters will terminate right over a load bearing wall (that worked out!), so I will build a third support for the new roof directly over that wall. That gives me 3 strong carrying point as you suggested. Then all I have to do is tie in the roofing components and I'm golden. Planning on using ice and water shield and felt over that.

 

Back to the drawing board. With appropriate slope for the shingles on existing roof, my rafters would be way too to far out where they meet existing roof. Back to gable roof plans... Now my speed bump is supporting the ridge board on the house side. There is a window right where the ridge will land on the wall and it doesn't look to have an adequate header as it is. That cuts my plan of running a mast up from the wall plate to the ridge board. Thinking of running another beam across where my new beams sit on wall. I am really trying to avoid pulling drywall and adding more studs/columns here. I could pour two new footings for some posts and put a beam on them also. Rafter ties?? Am I missing something here? Is there an easier way to frame it out without getting too crazy?

 

For any interested: I ended up pouring a couple more footings for another set of posts and beam right by the house. Now I can land a helicopter up there!! The new beam will carry the load from the ridge board and keep the weight off the wall. Big lumber coming soon (cypress).

 

Cypress??!! Really? A lot of money for framing, IMO.

 

Limited on options for local sawmills, but the cypress is just posts and beams. I actually think it will give it a really nice look.

 

Since most sawmill lumber is air dried which can take up to a year - how fresh is that lumber?

 

They have plenty of lumber that's been dried out, some well over a year. They deal specifically with cypress, so plenty of stock available.

 

Tbh cypress was not my first choice, but without paying bookoo bucks for transportation, I'm stuck with it. I actually like the look, but not too crazy on the price tag. I'm just rolling with it here.

 

Hey y'all, sorry I totally forgot to post after completion! Thanks for the advice everyone! If you have any questions please feel free to ask.

Blessings,

Thomas

 

Looks good

who was it said this

 

Thanks. I ended up just bringing my overhang out quite a bit to compensate for the height and matching the existing eaves. This was probably the most nerve wracking part for me. Time will tell how well the drip edge transition works. For what I lacked in skill and experience I made up for with silicone! Lol! I am glad I was talked into doing a gable roof, thanks again for the advice from you and others.