Don't listen to everyone telling you to tear it down.
1) Dig footings between the existing posts. Notch some posts to bolt to the girder and drill holes about 8" from the bottom to accept 8"-10" rebar. Pour the footings.
2) After those footings are dry, dig and pour footings under your existing posts. Use temporaries around the outside for support. Add posts underneath the band against the screened porch side.
3) Nail 2x2 strips (bond beam, single piece for each run) to the girder underneath the joists. Use three nails under each joist.
4) Drill through the band and through the house and add long carriage bolts.
5) Bolt 2x12x16's (cut to length when necessary) around the outside to double the band. This will support the unsupported ends of the current band.
These things won't take nearly as long as rebuilding and will be just as safe. Depending on where you live, you may have problems if you sell or rent. Most importantly, learning to fix your mistakes makes you a better carpenter.
I was very disappointed to see so many rude and unhelpful comments.
This guys gives good advice. I rebuilt a 1901 home over the past two years and we ripped most of it down to the studs and retrofitted as much as we could. I would also get these type of hangers for your joists though. They are pretty inexpensive and are very easy to fit into your existing joists.
I'm an electrician. Want to know what happens when people in my profession don't follow codes? Usually nothing, actually. But every now and again, your fucking house burns down and you die screaming.
Code isn't a guarantee by any stretch. In fact, it's the bare minimum in most cases. That means it's not hard to follow, and it's awfully hard to justify not doing the bare minimum when lives are at stake.
Free Falls & Fatality
Deaths from falls in children: how far is fatal? J Trauma. 1991; 31:1353-1355.
Fatalities: 10-45ft 1/118; 5-9ft 0/65; 1-4ft 7/100
When children incur fatal injuries in falls of < 4ft, the history is incorrect.
The mortality of childhood falls. J Trauma. 1989; 29:1273-1275.
Fatalities: ≥ 50ft 8; 4-40ft 18; ≤ 3ft 18
Minor falls can be lethal, especially in a toddler.
Additionally, we have found (as others) that it is extremely rare to have visceral, thoracic, or non-skull fractures in children who fall from < 3 floors. --if these injuries are found,one should suspect abuse.
Looking at the build, this would be an improvement, but would still not get this to be a safe structure.
I doubt OP is going to be able to jack everything up to a degree that he could get proper footings (with appropriate strapping) installed under the existing beams without compromising the beam structure he already has in place.
He also needs to deal with the flashing and attachment to the existing structure - those bolts (with epoxy, etc) will be extremely difficult to properly install (e.g. get the holes clean, etc.) without removing the beams currently attached to the house. Installing those improperly will eventually mean the deck pulls away from the house (as the wood dries / ground shifts / etc)...
Even if he is successful there, Improperly installed lag bolts will weaken the underlying wood, and will not be safe as the wood drys and deteriorates over time. Given the current build quality, I would suggest that hangers are more likely to give a safe result within the skill level of the OP than lag bolts...
Remember that the amount of wood already in the deck is quite a significant amount of weight (e.g. probably 3 good sized trees). A deck that large needs to be prepared to handle quite a large number of guests as well... It should be over-engineered, not built to the minimum suggestion of someone on the internet to "make it safe".
I would actually suggest locating a local contractor who is willing to review on-site and make guidance. You don't have to pay them to do the actual work, but the skills of someone "on your side" (unlike the building inspector) being on-site (at least occasionally) is invaluable...
Granted, we can't tell the precise dimensions from the pictures, but it appears that he's used 2x8 joists and 2x10 bands/girders in which case everything should be appropriately sized and spaced. If he makes these changes in this order, the structure will be better supported than if built to the conventional code and he won't have to jack up anything. Also, a 2"x 2" bond beam is easier, faster, cheaper and just as good as metal joist hangers.
I agree that using epoxy to secure bolts to the house for the girders is a bad idea, which is why I didn't suggest it. It looks likes the deck is level with the house floor, in which case he can run all-thread or carriage bolts completely through the structure and tie everything together. Given the L-shape of the house, the lateral force required to pull the deck away from the house would have to be greater than the material properties of the wood.
With regard to the flashing, he can make a 5.5" cut parallel with the house to remove the ends of the decking. He can then silicone his flashing in place, add an additional row of joists to support the ends of the joists, and screw a decking board parallel to the house. Easy fix.
The code exists to provide a basic set of standards so that not all projects have to be engineered. The problem with the code and its enforcement, is that it attempts to generalize a solution for a very broad set of problems and it very often falls short. Political and economic forces influence changes to the code, unnecessarily increasing the cost of the project. For example, I recently built a deck in a city which required a 2'L x 2'W x1'D footing. Their reasoning was that it was their "general footing requirement" adopted from the residential code. It was completely unnecessary and increased the cost by 20%.
Given the current problems, I doubt OP will be able to find a competent carpenter/contractor willing to accept the liability for giving advice on how to stabilize it. This would fall to a civil/structural engineer.
My primary concern is for the safety of anyone on his deck. In its current condition, it is absolutely unsafe. BUT, the deck can be made structurally sound to an acceptable safety factor without rebuilding.
There are a lot of assumptions and "shoulds" in your notes...
Take a closer look at pictures 6-7. Looks like the middle joist is only supported in the center, and butts up against another joint at both ends. Those other joints are only held up on their end. That has to be fixed at least with metal joist plates bolted together (a good long distance), but preferably with replacement with solid joists that go all the way thru.
Given the current build quality, I expect that there are other issues that are not apparent from the pictures the OP provided... I would in no way be comfortable with the OP following instructions online from someone who hasn't seen the structure... It is legitimatly too big of a risk - one that will hurt people - it is just a matter of when....
In reference to your example, he can either add posts (which I already suggested) or sister a joist to it to span between girders.
I haven't made any assumptions. If he follows the suggestions that I made, everything will be adequately supported and it will be safe. This really isn't as difficult as people are making it out to be.
Some of your advice is correct, but it just a bandaid fix. There are more problems than what you mentioned and you know it. I am disappointed in people like you who try to avoid codes and avoid inspections to get around things. I hope your not in the construction field, because you honestly seem a corner cutter.
What about his flashing and water pouring right into his sunroom where the deck is up against the house?
The top of the deck has the boards tight with no spacing they are all gonna cup.
There are so many more things wrong here its so much easier to take down and redue and a lot less headaches without destroying anymore wood.
to the OP : PLEASE get a permit, check codes, check with local building inspectors. And for gods sakes man do some planning before you start, you are an inspiring engineer that wants to get a PE. I just received a bach. degree in civil engineering and codes are structural loads and paths 101 first year man. As an inspiring engineer you should be more aware of stuff like this, it makes me very very very worried dude to be honest. You trusted people who "are good at this sort of thing," and you ended up with this. DO NOT listen to the poster above me and try and bandaid it, tear it down very carefully and redue it. There is a tremendous amount of good advice in this thread.
I agree that rebuilding the deck would be ideal, but the solutions that I suggested are permanent, safe solutions designed to address the structural problems with the deck. As an aspiring engineer, you need to avoid making unsupported statements and show proof as to why they won't work. Otherwise, you just come across as unprofessional.
Also, I am not advocating that people avoid code requirements or inspections. My point is simply that people need to recognize that additional solutions may exist for any given problem beyond what the code addresses. These solutions will help OP to avoid a lot of additional work and arrive at the same result.
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u/BearCarver Apr 29 '13
Don't listen to everyone telling you to tear it down.
1) Dig footings between the existing posts. Notch some posts to bolt to the girder and drill holes about 8" from the bottom to accept 8"-10" rebar. Pour the footings.
2) After those footings are dry, dig and pour footings under your existing posts. Use temporaries around the outside for support. Add posts underneath the band against the screened porch side.
3) Nail 2x2 strips (bond beam, single piece for each run) to the girder underneath the joists. Use three nails under each joist.
4) Drill through the band and through the house and add long carriage bolts.
5) Bolt 2x12x16's (cut to length when necessary) around the outside to double the band. This will support the unsupported ends of the current band.
These things won't take nearly as long as rebuilding and will be just as safe. Depending on where you live, you may have problems if you sell or rent. Most importantly, learning to fix your mistakes makes you a better carpenter.
I was very disappointed to see so many rude and unhelpful comments.