Roof Over Question

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I've been given the go ahead by my local building inspector to put a new roof on a mobile home I'm working on. The basic plan is 2x6 rafters (which I've already built) and a metal roof (going over top of the existing domed roof). An area of concern for me, particularly as last winter brought very high winds, is making sure of a good attachment to the mobile itself.

The building inspector requires me to put a 2x4 plate on top of the existing roof, and suggested drilling holes in and using ready rod through the existing top plates to hold down the new plate. Well, that's great, except the walls are finished, and I have no desire to rip them apart to put bolts on.

I've heard of expanding anchor bolts, though they seem to be designed specifically for concrete? The other alternative that I thought of was long lag bolts and then using hurricane ties to attach the rafters themselves directly onto the mobile's stud home. Any would-be engineers out there have any ideas?

I've attached the approved roof plan.
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Hi,

I apologize for not knowing the answer to your questions. I will monitor your post and if it is not answered shortly I will send out some emails to the ones I know that do have the knowledge.

Thanks for your patience.
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I personally would never attach a roof to an existing mobile home. I would build the new roof something like a skeleton Pole barn and that structure would be self supporting. The reason for this is that you get away from touching the home completely. It can be braced for any wind load. These type of structures are approved all the time in my jurisdiction in Ohio.

Since a manufactured home is inspected at the factory to HUD plans it is a violation of Ohio and many other building codes to impose any additional load on the roof of the mobile home. If anything happens to your home because of a modification required by a building inspector the building department has a big problem on there hands.

Usually mobile homes are not in the CABO or any other code book for residential dwellings except for the HUD requirements. Ask him to show you where the section is in the code that requires you to attach the freestanding new roof to the old mobile home roof. If he is requiring it then it must be in the code. Building Inspectors are not allowed to make up the building code(law)as they see fit.

BTW if a storm happens the items he wants you to do will cause more damage to you home than if it was left just as it is. While I am a Certified Building Inspector in Ohio and other areas I would never ask you to do what he is asking. Period

The only reason I mention my certification is to make it clear I have been there,got the shirt, and got the hat. I really do hate it when a building inspector wants to make people do unnecessary work to pass a inspection.
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Hi Mobile newbie,

Have you purchased Marks Repair Manuel. In the manuel is instructions for a roof over. Many forum users have done this, all with great results.

In my area of the world to alter your roof in this manner we would be required to get an engineers report, and then prints made by an architect, then present to the local officials.

I noticed you did not have a profile so we have no idea where you are located. If you could supply more info about your weather conditions, snow loads, hurricanes, etc, others may better be able to give advice.

~Yanita~
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Hi MobileNewbie,

Since you have already built your trusses and this an older thread, my post probably won't change things for you. I was very hesitant about replying to your post because I didn't want to sound negative. But with your indulgence, I would like to offer up my opinion for other users that might find this thread.

I would never recommend that anyone put 2x, plywood and shingles on their metal roof mobile home. At the very least, get a true engineering report before attempting it. Any roundtop mobile home is not built to hold that kind of weight. I see you made your rafters to span over the existing roof, which is a good idea, but that puts all the weight on the walls.

No matter what type of bolting you do to the rafter sill plate to the stud wall top plate, that wall top plate has only a few small 2" galvanized straps to help hold it down. This may have been good enough for the original metal roof, but will not be enough for a large overhang. The overhang can catch severe winds which could pull the rafter roof off of the mobile home, or possibly rack the home itself.

The weight factor is also a major concern. On a 14x60 for example, 2x6 rafters, 1/2" sheathing/plywood deck, shingles, felt, nails and bird droppings is well over one ton total weight, depending of the type of birds.

Again, get and engineering report or call the factory if they are still around. I know that putting a shingle roof on a roundtop MH would not be permitted in my area.

Just my thoughts. I do hope your project goes well and your roof serves you for as long as you need it.

JD
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I've had these odd problems in a bathroom... For several months, when the clothes washer would drain, sometimes the toilet would gurgle. Also the toilet would sometimes have a weak or no flush and we'd plunge to get it to go.

I have the drain diagram for the house. There is an autovent in the wall behind the washing machine. Then in the bathroom, there is a true roof vent behind the tub. The sink has another autovent. The tub's drain joins the toilet's drain when then goes into the main for that side. The sink has its own line going into the main. I assume the vent behind the tub is supposed to handle the air issues from the toilet and the autovent is supposed to handle the air from the washing machine. Is this correct?

The other problem I mentioned is the toilet started to get really backed up... over the last few days it would absolutely not flush unless I plunged the heck out of it. Then it would only work once or twice. So last night I pulled it out and snaked it and the drain... nothing inside. WHen I put it back on, it seems to not plug anymore and flushes (so far). So I'm really baffled with all this. The tub and sink drain fine. btw we wash our dogs in that tub and the drain is known for having dog har in it.
Any advise on what the blockage is? The vent behind the tub?
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Our Daughter had problems with her's too, I ended up snaking it, and found dog hair also. her's was from the Rainbow vacuume cleaner being dumped into the toilet.
As long as it is working, I would think it was a clog of some sort. Greg
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Have checked the trailer for level and when I check it with the water level at the blocking points its perfect. But the 3 feet or so that cantilevers out past the frame to the outside walls is sagging a 1/2 ". Not sure how you would go about bracing this. Any thoughts would be appreciated.
Thanks Rob
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Do you have outriggers on your frame? They should hold up the cantelevered area. They can be bought too.

Jim
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Rob, It sounds like you will need to do perimeter blocking. This is basicaly blocking the outside walls under the rim joist. Does your home have a shingle roof? Greg
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Thanks yall
I do have outriggers. Yes it does have a roof over with one layer shakes and one layer of compositon shingles and metal roof on top of that. The trusses sit on top of the origial metal trailer roof.The outside walls are 2x3. I was planning on using 3/8 sheetrocking over the paneling on the walls. I guess I am gonna have to do some sort of bracing out there ??
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Hi outer,

I'm just gonna throw this out here!

But, if you have the original roof.. metal, then shingles and a shake roof on top of that, you've got much more weight on top than your home can handle!

How were the trusses constructed, and out of what?

If you've got 2x3 frame walls... it can't take that amount of weight from the roof... and roof over.

Bracing anything won't do it, you need to really look at the structure of your home.

If you use the sheet rock right now, you'll be doing even more repairs down the road.


Our homes aren't designed to like stick builts. If you got 2x3 exterior framing, then you really have to be careful.

Like I said, just my opinion!

Maureen 8-)
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With the extra weight of a truss roof put on top of your home, I would think edge piers would be the best way to support the outside walls. I doubt that you will be able to straighten the floor but it may correct some over time. The edge piers I use are like the image below, except 2 of the legs are straight up vertical to allow the pier to sit next to the skirting. You would also need footings if you are in an area that requires them. In my area, treated wood pads are all that is needed.

Probably the best answer would be to remove the added roof material and install a true mobile home approved roof on top of the original roof. But that would just alleviate the cause and probably not undo the damage. I would think twice about adding to the weight of the walls with sheetrock though. Painting the paneling is not a bad way to go.

JD
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I recently had a light switch give up on me in our master bath. I went to Home Depot and bought a replacement. When I removed the switch plate boy was I surprised. No gang box. I had no idea the switches were self storing. So my next project will be going through and installing gang boxes at each switch location. Oh the joy of owning a mobile home!
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One of the "features" of mobiles. A word of caution, use care when you install the new boxes, most of the drywall is only 3/8" so it is easy to break if you fight too much with the box & wires. Greg
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