possible collapse, shorter post
Thank you everyone for replying. Sorry about the lengthy post. Here are the quick details, a 20x20 deck, with a two piece 20 foot 2x8 ledger, lag bolted with a single center row of lag bolts. The ledger hangs past the house corner 5 feet, so 15 feet of ledger attached to the house. 7 posts to be used, 2 rows of 3, and one under the end of the ledger that is not connected to the house. All posts are ten feet apart. Posts are to be 6x6, sitting on 8" nominal sonotubes. Beams are to be 2x12x20, bonded with adhesive, and nailed. 6x6 are to be notched to accept the beams, which will sit flush. Joist hangers on both sides of center beam, hangers on the ledger, hangers on the end beam. Soil is clay, slope is about 20" over the twenty feet downward away from the house. All wood is PT. Posts will sit on post anchor in cement. Joists are to be 2x8x10. Most holes have hit water, none are below the 42" frost line. Ledger corner post supporting free end hit a large rock 12 inches in. Will this deck stand up? Should the area be back filled in order to have the cement columns be under the frost line? Contractor says ground never really freezes that deep, 30" is hard frost. In regards to inspectors, permits etc. There are no building inspectors here, there are no permits. Parents live in Vermont, near Rutland, not in the town. Small town, no permits needed. Didn't need one for the house, or garage etc. You just have to pay the additional tax when they assess it. I'll post photos in about 90 minutes. Thank you all again, I really appreciate busy individuals taking the time to help a naive stranger.
Re: possible collapse, shorter post
The details I've marked in red really scare me.
Originally Posted by stevemcmaine
- Lag bolted with a single center row of lag bolts - Lag bolts should be staggered to prevent splitting of the ledger and distribute the stresses.
- 2x12x20, bonded with adhesive, and nailed. - Two 2x's laminated will promote rot because moisture can penetrate more easily and deeply between two pieces of lumber.
- 6x6 are to be notched to accept the beams, - Not sure what this means, but the implication is that you've got a notch that is 3" wide and 12" deep in the center of the post. If this is the case, again it will only promote rot because moisture will be trapped within the wood structure.
- Most holes have hit water, none are below the 42" frost line - Footings need to be below the frost line PERIOD! If they're not, you will get heaving. There's a reason that minimum standards are set per local jurisdiction, if your local jurisdiction says 42", then make sure that the footings reach to that depth.
- A large rock 12 inches in - Again, if the frost line is 42", it's 42", NOT 12" While the rock may be able to support the weight, it's not deep enough to withstand freeze/thaw cycles of your winters.
- In regards to inspectors, permits etc. There are no building inspectors here, there are no permits - I grew up in the sticks and even in no-man's-land there are building regulations and permit requirements. The difference between no-man's-land and downtown metropolis is getting caught. Now, I'm not suggesting that you needlessly pay revenue enhancements to the governing authority, however, there is still a difference between proper building techniques and fly-by-night builders getting by with substandard work and the local building department helps to thwart the latter.
I still recommend stopping the work until your concerns have been allayed. A couple calls to engineers or architects who can do the calcs on the current plans/specs - whether permits are required or not - is the only way you'll truly know if the plans meet minimum specs for your locale and will withstand the elements and test of time.
BTW, thanks for highlighting your original post, this one was much easier to understand and stick with.
Re: possible collapse, shorter post
Re: the boulder. Try digging a large hole next to it and drop the boulder into it.
Re: clay. Go 12" deeper with your post and make sure you have at least a 2' x 2' footing at the base.
Tags for this Thread