Hi, I have a rental property that was damaged by fire. The house is a 1-1/2 story over a 3′ crawl space. The property is in a flood zone and the county insists that I elevate the remaining structure to conform to current code before I begin repairs. My plan is to rebuild with a full second story. A brief inspection convinced me that the existing footings and foundation are not up to code, so I am planning to have the house jacked up, replace the entire foundation and have the house lowered onto the new foundation.
My question at this point is: how does one attach an existing house to a new foundation?
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how does one attach an existing house to a new foundation?
I don't know, but house movers do it all the time - you might contact a local house mover. And your engineer will specify the details on the drawings.
edited to add: I'm pretty sure it will be the same as with new construction in your area, ie: anchor bolts, hd hold-downs if in a seismic area.
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Edited 9/30/2007 3:47 pm by Huck
Thank you for the info.I am trying to stay as involved in this project as I can, and for me that means trying to understand the options, and so far, I have not got a clear picture of just how they will be able to addach my existing house to a new foundation.
The engineer who draws the plan for your new foundation should give you a drawing of the connection.
Here where I live, anchor bolts are generally embedded in the foundation when it is poured, and will protrude through the bottom plate of the walls. A nut and washer attaches the bottom plate securely to the bolts. You will have to open the walls at periodic intervals to do this, as specified on the engineer's drawing. You may have to add plywood sheathing, also, which strenthens the bottom plate's connection to the rest of the house.
An HD is a steel bracket that is sometimes specified, and it generally is attached to a 4x4 post in the wall (again, with plywood sheathing on the wall), and bolted to an anchor bolt in the slab or foundation wall.
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Edited 10/1/2007 11:11 pm by Huck
It is easy if you are going to frame a pony wall under the floor joists and on top of the new concrete. Since you are raising the house you are probably going to want to do it this way.
Have the house movers raise the house above its final elevation, temporarily. Pour the new foundation ~6"above finished grade. Frame a pony wall to the correct height for the permanent house elevation. Leave the plywood off the outside of the pony wall--put a bunch of solid, temporary diagonal bracing on the inside instead. Have the house movers lower the house onto the pony walls. Remove the existing sheathing to expose the lower half of the rim joist. Install plywood on the pony wall and rim joist, tying the mudsill to the rim joist. Remove diagonal bracing.
Be aware that this is a major undertaking that will affect your plumbing, electrical, mechanical, stairs and porches, siding, and other elements. It also requires careful communication with the house mover so that s/he can do the raising and lowering in sync with what you are doing.
I could not figure out what in the devil you were talking about.Then it hit me - that would work for one style of house construction. Nothing like we do here though. I would not want ponywalls in a flood zone. They'd be too easy to wash out and collapse, unless specially built for the shear and live loading.We try to go 18" above grade with the concrete or masonry construction and then the sill and rim sets direct on that.Another point for him to consider re raising this up - the flood codes disallow any living spaces except where the finished floor is 12" above the flood zone elevation survey for that location. That means that no living space in any basement that he might be creating by raising things.
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What I described is typical platform framing on the left coast. Masonry just above grade (sometimes stepped to the hillside), pony walls on top of that with a single or double top plate, and then joists across those walls. Plywood tie from the mudsill to the midpoint of the rim joist is important.
No flooding here on the island, but just across the way there is a big river valley and I see some homes over there that are obviously built (or later raised) to keep the first floor above high water mark. There are some where the stemwalls are 4 or 5 feet tall, and some where there is wood framing below the first floor. I don't think that most of them would encounter a lot of force from flood, mostly just rising and receding water that got everything wet. But you raise a good point about local code--there doubtless is such a thing, and next time I am talking to an off-island sub I will ask what he knows about it.
A guy I worked for about a million years ago had a method of pouring right up to the mudsill. We would shore the house in place, demo the brick foundation, form a new one right up to the mudsill, and then cut holes in the forms (or even thru the mudsill) to allow concrete to be pumped in. The anchor bolts would already be hanging. Once the crete had cured a bit the cribbing was pried out and there she was. I'd rather raise the house a few feet or more above eventual height, so I ain't gotta crawl under it. On some I have worked on we got them high enough to drive a bobcat in.
Thanks again.That is a great idea to pour the foundation, I was thinking only about block. I will talk to a mason about that option. Thanks again.
If you go with a poured concrete foundation and no pony walls, you can connect the house to the mudsills using a variety of methods. The plywood sheathing is the most likely... it is nailed to the mudsill at the bottom, and to the rim joist and then wall studs as you move up. A common Simpson strap around here is this one, different from what Huck showed:
http://strongtie.com/products/connectors/LSTHD-STHD.html
These are embedded in the concrete and poke up on the outside of the house, waving in the breeze until you come along and nail them to the wall. This lets you do a lot of framing before you have to make the actual connection. If you are not going with pony walls, and/or are not raising the house above the final elevation while you do the work, they might be a good choice. You will probably need a structural engineer to tell you (and tell the building department).
Thanks for your input.My house is on a tributary to the Chesapeake Bay. The existing foundation put the finished floor right at what then are now calling flood level, and is already about 3 ft. above grade, although the floor did not get wet when Hurricand Isabel came through a few yrs. ago.Since the county is forcing me to elivate a minimum of 1 ft. above its current position, and the existing footers will not pass code, I am planning to have the house jacked up, the old foundation removed and a new foundation- from the footer on up- installed to raise the finished floor 4 ft. above its current position.
Thanks for your input.I dont know that I can use a pony wall in a flood zone. The house is on a tributary to the Cheseapeake Bay.After Hurricane Isabele came througe a few yrs. back a lot of houses were elevated in this area and all that I saw got new masonry foundations.Since my existing foundation will not pass code, my plan is to remove it completely and have a new one - from the footer on up- installed under the elevated house.
You will need to study your local flood zone ordinance for the details.
The national guidlines are fairly strict for houses in flood zones. The attachment needs to be stout enough to keep it from washing away, floating along, and taking out the bridge - or whatever.
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jpf,
Have you looked seriously at the cost of starting over? simply knock down what you have and start from scratch.. You'd be amazed at the potential savings doing that..
A block away a family had a kitchen fire that gutted the kitchen, when the cost of compliance was added to the cost of rebuilding the owners found it was cheaper to build new than repair and update..
Plus the value of the house reflects new construction.
PS they were going to reuse some of the studs etc, untill the smoke smell convinced them other wise.
Thank you for the input.I did think about starting over from scratch but my initial pass with working out the numbers headed me in the direction of rebuilding.I think I have very good insurance(Nationwide) and my agent informed me right after the fire that I have Code Compliance coverage. The gotcha here is that the code compliance coverage is reimbursement coverage. I was told that the elevation costs and the foundation work will only be covered if I incur the expense.
jpf,
by how much did it cost more to replace than rebuild? Did you adjust those numbers for the inevitable unforeseen which is never covered by estimates but always occurs in reconstruction..
Freenchy has a really good point there. I have no doubt that it would be cheaper to demo and rebuild on the same footprint, except for the possibility that codes would not somehow allow that.
For instance here, NOBODY can build in a flood zone except for maritime businesses that depend on immediate proximity to the water in the nature of their business.
But existing structures are grandfathered.
In a case like yours, there are then a couple of exceptions and exclusions and restrictions that would enter into the whole decision....
So you really need to investigate ALL the possibilities and options within your local rulings.
For instance, if the lot is large enough, could you rebuild in a higher place on the site?
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Thanks for the input.The Chesapeake Bay Preservation Act restricts how close to the water one can place a new structure, but since mine is a pre-existing structure, I can rebuild on the same foot print.My initial run through the numbers convinced me that my economic solution was to repair, not to start over from scratch. As I mentioned to one of the other responders (frenchie?), my insurance agent told me that my code compliance insurance only covered incurred costs, ie, they will pay to elevate the house only if I in fact elevate the house.
One way or another, the ins co needs to make you whole. It sounds like you need a builder who is familiar with all this in your area who can act as an advocate for you with the insurance company, explaining to them how it is less expensive to totally rebuild than to try saving this while lifting it up. and replacing the foundation under it.Without being there and see all the details and knowing all the local regs, I'm afraid our advice here can only be generic.
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my first thought was call the dozer and go on. but after reading the thread and understanding that insurance will pay for raising and make it to code i can see the reasoning to repair.versus if you tear done you get a check for x amount and the new foundation etc. is your problem.i'd just find a good contractor and let him figure all the problems out and send the bill to insurance and live happily ever after.
just curious do you have loss of rent also? that could add up to alot by the time this deals done. larrywhy pay someone to screw it up,i can do it for free....
yes I am loosing rental income.....ouch.
my state farm policy had a loss of rent on it,i didn't even know that ,someone on here mentioned it to me and i checked.so you might ask. larrywhy pay someone to screw it up,i can do it for free....
I don't have it. I don't recall if they offered it an I turned them down, or maybe they forgot to offer it when I took the policy out.