We live in a mobile home here in Montana on a concrete slab with cement blocks all over the place underneath. Would anyone know if it is possible to add on a room with a basement beneath the room to this setup? And if so what must be done to insure minimal seasonal movement, etc. Thanks.
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Maybe, but why not put the basement under the mobile home?
around here, they add a room to back of mobile home, then add one to front.Put a roof over the whole thing. then pull the trailer out, frame up the end walls and call it a house.
Set your mobile home free.If it truly loves you, it will come back. If not, it wasn't really your mobile home to begin with._______________________________________________________________
It ain't what you make, it's what you don't spend
You certainly could do this several ways.
If you want to add a room with a permanent foundation, and physically attach it to the mobile home, either the mobile home needs to be on an equivalent (ie, deep, frost-proof) foundation, or the connection needs to be somehow flexible (able to move several inches up and down).
The most straight-forward (but probably not cheapest) approach is to dig a foundation/basement for the trailer+room, cover over the trailer part with a concrete slab, and plop the trailer on top. Have tie-downs for the trailer (along with utility connections, prossibly) cast into the slab/foundation.
Otherwise, you can have the room built, then have holes bored down to the frostline and filled with concrete for trailer footings. This isn't quite as good as the first option -- there likely will be some movement between the two structures, but it becomes maybe 1/4" or so instead of several inches.
Or have the room built, leave the trailer on it's existing footings, and connect the two with a "gangway" (or maybe "jetway") that will allow for several inches of motion.
FYI, if you add a stick built addition to a mobile home most lenders will not give you a mortgage on it. Hybrids are considered unique homes and most lenders won't touch them.
Just something to think about...
There are ways to do this, but details would help, especially budget and who are your neighbors. As other posters have alluded to, you could do a lot of work, spend a lot of money and end up with very little value. Also - what do you need the space for? And can you move the home at all in the process?
There are mobiles with basements, mobiles with additions (even multiple additions), mobiles with pavilion style roofs and double/triple mobiles pulled side by side. None of them I've seen would classify as fine homebuilding, but we've all gotta live somewhere.
Let us know more and we'll help all we can.
The devil is surely in the details. This a double wide with sheet rock, 2x6 construction. The cement pad is 28.5' x65.5'. The addition would be at a 90 degree angle to the current 64'x27.5' rectangular structure. A basement was a possibility on initial purchase but with a steel frame instead of a modular frame it would have required a very deep basement and that was not in the cards financially at the time. A "jet way" or skyway would be my preference but my darling bride might not go for it. Why do we need more room- because its there. Living in Montana where a loaf of bread can be quicker to secure by growing the wheat, milling the flour etc than driving to town some 30 miles away requires high mpg vehicles so no van available. Two Toyotas with 900 hundred thousand miles on them might be an indicator. We live on the reservation and there are few inspectors. The common opinion is if you want to build it go ahead. Lenders here probably aren't as choosey as other places but you might have to put up 500 acres as collateral for a half acre homesite. And as far as a lender is concerned, "We don't need no stinking lender".
I suppose more succinctly, I was wondering if there is some method to connect the floating structure to the basemented structure that would possess flexibility. Knowing little of structural engineering I don't know the degree of movement that we would experience. Are we talking movement in the neighborhood of 4-5 inches or more like 1-2 inches? Two decks bolted to the framework and simply perched on pier blocks haven't budged in 7 years. We are on very sandy soil with a healthy perc rate. So I don't know if that is a consideration. Wind is a small matter although tiedowns would be good. The two halves of the house exceeded the weight of a typical double wide when they pulled it through the scale. This is a house we bought from the son of a large mobile dealer in south central Montana so it has all sorts of amenities not commonly found in standard products, thus the added weight.
Neighbors as you can guess are not an issue. Resale is not a big issue either. Quite likely we will retire here and with no kids we'll let the nursing home figure out how to move the basement with the rest of the house. It is physically possible to move the house but the inconvenience of that would probably be too great. Being a transplant from the midwest I miss a basement and unlike those in many midwestern locations it would be "dry as a cork". Additionally it would allow us to put the utilities where they are not such a hassle and so vulnerable. Moving the furnace would be make the house so much quieter.
Fine Homebuilding wouldn't even venture to look at this dwelling. I am constantly amazed at what has become the expectation for a house these days when I visit the Twin Cities. Do people really occupy all those "starter castles"? How many of us boomers grew up in a house with less than 1800 sq. ft. and shared a bedroom with 1,2, or sometimes 3 other siblings and somehow managed to have a satisfying childhood. Living simply, without even considering economy and ecology, has tremendous benefits. Bought and paid for is also less stressful. We paid 56 for this place so its not real "fine" but the view out all four sides has us foregoing curtains. Besides when the closest neighbor is a quarter mile away, pjs and bathrobes are optional. Thanks for the comments.
A lot depends on the soil, but it's not unusual to see 3 inches of frost heave around here. Six inches would be a bit much.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I like your spirit - I was wondering what the neighborhood was like - I thought you might be very rural...now its clear.
There may be specific products and details for your situation, but I don not know of any. I would think the main concern would not be structural, but cosmetically covering the results of one building moving independent of the other.
My granparents live in a house that was two houses, shoved together, sitting on the clay - the spot in the hallway where they attach is a little different as time goes on, but you cannot see it in the paneling. Drywall would be a different story.
Some random thoughts:
I am thinking if you connect the two via a short hallway, the hallway will take all the stress, and leave the two structures relatively isolated from each other. From your comments, it sounds like movement is not that big a factor.
I would cover the interior of this hallway in tongue and groove boards (or something similar) where it could be subject to motion, and stay away from drywall in that area. I would also leave provision for detaching and moving the mobile, should that become a reality in the future. Floor joists could cantilever off your foundation in the new structure, and the trim that makes the transition could be nailed on one side only etc...
If I were in this situation, I'd be tempted to build another structure entirely and some type of covered/enclosed walkway between the two.
Treat every person you meet like you will know them the rest of your life - you just might!
The one room addition's easy, just hitch up to the van.
Not sure about the basement.
:>)
I've built a couple garages and a couple additions for manufactured homes.
It's my understanding that, the reason these dwellings are permitted, by code, in various jurisdictions with otherwise,more stringent residential building requirements, is that their specifications fall under H.U.D. (Federal) and thus are outside the scope of local structural codes.
In Oregon (and I suspect in most other jurisdictions governed by the International Residential Code, et.al.) structural additions to manufactured homes must be "free-standing."
While the additions can be "attached," a framed and drywalled firewall must exist between the addition and the MH and the addition must have it's own foundation structure.
The exception to this is that, when a gable roof intersects, a cricket may extend from the addition onto the roof of the MH.
I would suggest you consult your local inspector to see what's required in your area.
As far as a basement excavation, I've seen a couple manufactured homes locally that, before they were positioned, a daylight basement structure was built (with CBU's on a slab IIRC) and steel I-beam joists layed across the top of the basement walls and the the MH set onto the beams.
In my local, that would require an engineered plan, but we're in a high seismic zone.
Manufactured homes, while not fine homebuilding, do serve a purpose....If they're set up properly on a concrete pad with tiedowns as required by the manufactured home society or what ever it is, and properly skirted, with good drainage and are occupied by folks who don't house 2 or 3 big dogs, control their kids and generally take care of the home, they can last a long time. The roofs are somewhat flimsey and subject to damage from limbs and trees.
I'm not particulary fond of working around them because they are built a bit different than a conventional house (the absence of a rim joist always bothers me, as does the really, really light roof framing and sheathing).
But they do provide affordable housing to a lot of people with limited incomes or resources.
Insurance carriers are pretty frightened of "mixed construction". They don't like to have stick-built combined with modular/mobile. Mixing types of wiring, roof-overs and roof junctures.
Greg
We are already a rate class 10 and so we pay dearly. Foremost will often cover mobiles and because I'm now AARP eligible that is an avenue as well. We have 14 gauge wiring in the mobile but I always insist on 12 gauge and steel roofing is commonplace here. So perhaps that will prove a feasible way to marry the two structure together.
i own a mobile that has had a addition on it,we use it as a cabin. heres what has been done to it. 12x50 ,someone went in the center of the 50' side and cut a 24' hole in it and then put a 12x 24 addition on it. mobile is sitting on blocks and tied down, addition was built on piers on 12' centers.floor ,walls and cieling are all tied together. now fine homebuilding this isn't. but it has been this way since 1980 and been fine.to be real honest i just came from there and we are discussing tearing it down,but the reason being is it's a mobile home thats 37 years old and they were really built cheap back then.
on your house i would tie the mobile down real well,build the additon,where the sheetrock hits the mobile i would use a moulding to cover up the crack and go on.maybe two different flooring materials or some carpet and enjoy. when the nursing home comes and gets it,it's their problem. larryhand me the chainsaw, i need to trim the casing just a hair.
Go with the Sawzall because its insulated for when you sever that electrical line. Been there done that. The chain saw might not offer that much protection.
in TN they dig a hole set in a shipping container or and old truck reefer and then backfill over it and set the moble on top... gives em a nice place to grow the pot...
wish i had a picture of one i use to pass by.... backed an old bread van (the rounded looking step vans with the V split windshied) and best i could tell just flashed it and added alot of black tar... now the have an extra bedroom with a nice windshield... i mean window...
not make'n fun... the ones i see now where they are double wide and bring the roof in as a third member and crain it on top... no one would know it was a manufactured home...
I think i'm with others on this... i'd build it slightly "detached" 7-10 ft... build it conventional and then add a breezway... to connect the two... i'm sure you could make it look like it'd always been built that way...
good luck
p
First you said the house was a mobile, then you said it was a doublewide. I'm confused. Mobiles to me are typically up on blocks with the axles still underneath them, usually about 12' wide and variable lengths. Doublewides are two sections that are joined together on site after they are levelled, then the siding is added on the two "end sections", a different beast. Doublewides around here typically have a low pitched roof and cathedral cieling. Mobiles have much less pitch, almost flat, rarely shingled.
If this is a double wide, it's already on a substantial "foundation". You mention 2x6 walls which are as solid as you should need. Make sure that it's properly fastened to prevent both vertical and horizontal movement. I think the new addition will work with the existing if both foundations are equally solid and if the two sections are adequately fastened together. If you are going to join the two roofs, that's going to be another way they are going to be tied. (Use a good roofer, plenty of snow and ice shield and make sure everything is flashed, not just tarred.)
I wouldn't bother with the gangway unless that is what you want design wise. To me, that would make the addition stand out like a sore thumb. The biggest area that I see as potential problem is the actual "joint" where the two walls meet, presumably at a 90 degree angle, and if the structures behind the siding are properly joined, I don't even see much of a problem there. That corner would need some kind of flexible caulk - in case there's some movement. Even 1/4" would break a paint line and show a crack.
Good luck.
Don K.
EJG Homes Renovations - New Construction - Rentals