Thimble advice on a mobile home

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mayhem

Minister of Fire
May 8, 2007
1,955
Saugerties, NY
Greeting all. old poster been absent for a decade or so since I sold my old house with a wood stove. Now adding a pellet stove to my manufactured home and I think I need some advice.

Got myself a great deal on a used Englander pellet stove. In nearly new condition, owner was a fanatical maintenance person and it shows. Test fired it in the back of the pickup before bringing it inside. I decided in a basic through the wall and then vertical run to the exhaust. Bought a Duravent 3" kit that came with everything necessary, just getting to the install today. Bought a 7" hole saw and cut the sheetrock no problem, cut out some insulation and went to the outer wall...only to find that the outer wall of the house is made out of styrofoam. I've never seen nor heard of something like this, but I'm sure its probably a fairly common mobile home construction technique, makes it light enough to truck and I'm sure its a big part of why its so well insulated considering how thin the walls are.

So now I've got a nice, clean 7" hole in the wall of the house, I can use sheet rock anchors to get the inner thimble secured properly, but I'm a little stymied on what to do with the outer thimble. Do I need to build a wood frame inside the wall to get some screws into securely or is there another safe method I should be looking at here? I was thinking long bolts that would mate up the inside and outside halves of the thimble, but is that an acceptable solution? I feel like outside of a little frame maybe nothing will really be strong enough to support the chimney properly.

Once the thumble is secure, more or less the same question applies to the brackets I have to install on the outside. I can screw them into the vinyl siding, will that be adequate?

Thanks in advance.
 
After thinking it over and realizing the studs are pretty close together I've talked myself into just framing it in and it'll be done and sturdy. Only answer that really makes sense and its not much work.

The top bracket will be directly over the wall stud, so it should be nice and secure too. Lower bracket I can probably get onto the upper part of the frame.

Thanks!
 
Framing in is the preferred method IIRC. So I think you are doing it right.
 
Used to sell and setup these homes and never seen one that used Styrofoam on the outside wall.. But under the foam their still should be the plywood wall that you can screw through since the plywood wall is what give the unit structure and keeps it from twisting apart
 
Used to sell and setup these homes and never seen one that used Styrofoam on the outside wall.. But under the foam their still should be the plywood wall that you can screw through since the plywood wall is what give the unit structure and keeps it from twisting apart
I didn't want to believe it either, but yup. My exterior walls are sheet rock, 2x4 studs, some pink insulation and the outside of (at least this section) of the house is a layer of styrofoam and the vinyl siding is over that. There is no plywood visible. Surely there must be something else at least at points so the siding has something to hang on, but yeah...styrofoam.

Got the install done, called for an inspection and have been using the stove a few hours a day now. Just getting a feel for it. Gets the house too darn warm for my tastes, but its not getting super cold out at night so it ought to be great in the winter...assuming we have a winter this year.
 
That is interesting, they probably have 1/2x1 slats on the outside over the foam for the siding to strap to similar way they do some homes.. I have never seen a trailer or house for that mater that did not have some sort of board on the outside of the house...