coloradohoosier
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Re: Total Rebuild of a 1979 Dodge Class C
Yeah! That's a good, commercial type VCT. It should hold up very well, and be almost as sealed a surface as sheet goods like vinyl or linoleum (nobody actually uses lino anymore --- it's just generic for sheet flooring, which is all vinyl now). Hey OT, I've been following off and on --- sure sorry to hear about losing your Dad and Mom. My heart and prayers go out to you and yours.324Views0likes0CommentsRe: Fixing water damage on the old Dodge (pics)
Hey Spec! Glad you're settled in, and I too would like to see you back at the MH. I've been following Old Trucker, off and on, but just saw your thread tonight --- read the early pages, then jumped to the end. I've got an '85 Fleetwood Rallye built on a Chevy chassis. You were making me feel really guilty earlier about not dealing with my much needed cabover rebuild (which is getting even more needed over the winter.) My projects tend to overlap though, like yours seem to. Looking at the calender and your posts reminds me why my wife tells me not to start on the RV. Good luck getting back to it! It looks like you'll finish well, when you do finish.399Views0likes0CommentsRe: Total Rebuild of a 1979 Dodge Class C
TreeSeeker wrote: The truth is, an RV is a pretty small box to heat or cool, so the benefits of insulating, vapor blocking, etc., are probably pretty marginal when it comes right down to it. I am not so sure. We have friends whose cabin was gutted and rebuilt with 6 inch insulated outside walls. They heat the LR/Kitchen (about 20x15 ft) with about 3-4 logs for an evening when it is in the 30s outside. My living room is about 10x15 and is uninsulated. It takes about 10-12 logs to heat it when the temps are in the 40s. So insulation can make a huge difference in the amount of energy required for heating. Granted the amount of fuel to heat even an uninsulated RV would be much less than heating an insulated house, but you are limited in the amount of fuel you can carry. So, if you have good insulation in your RV your limited fuel will last much longer. I think the vapor barrier is important because the humidity in an RV will be higher than in a house since you have such a small space. People are still expelling just as much water vapor in their breath and you are also cooking. So the same amount of water vapor is being generated as in a house. If this vapor is condensing on the inside of the RV walls then you are going to have mold problems. You're right, TreeSeeker. I didn't mean that the benefits are nominal, but just that exactly how thoroughly one does it is less critical than in a year round residence. I guess I wasn't clear. I built my daughters a two story playhouse years ago (11x7 main floor and 11x5 upstairs) and insulated it. In the middle of winter a small ceramic space heater will keep it toasty warm, and once it warms up the thermostat on the unit hardly kicks it on. That's with single pane storm windows that I used as primary windows because I got them for free.369Views0likes0CommentsRe: Total Rebuild of a 1979 Dodge Class C
lzasitko wrote: And I too have been in Construction for almost 40 years. I have done everything from Design (still do a lot these days for other people) to building. I have built everything from small houses to large care homes and up here building code says that the ceiling has to have a vapour barrier. You can use the paper faced insulation but here it is not that common, fiberglas, rockwool (Spun rock, non combustible) sprayed foam (only way you don't need a vapour barrier as it seals itself) sprayed in cellulose (Paper) etc are more common. Walls are always sealed as tight as possible and in a house it is very common to see air to air heat exchangers. No matter how tight there is no such thing as air-tight, air will always find a way in. You are right in that up here furnaces have their own fresh air vent. I know that homes and other building usually have an air space above the insulation in the roof and venting properly is required so that moisture does not accumulate. And yes RV's are a different process but the basics still apply. RV's will never be sealed as tight as a house, there are simply too many ways for air to get in and out. I will disagree with your comment about it not being worth it to seal it as tight as possible. If it was me rebuilding an RV I would spray foam the whole inside instead of using batt insulation. Any time you can slow heat loose and limit air movement it will cost less to heat or cool. also my two cents worth :) I can't speak on how things are done that far north, Izasitco. I know how they are done in Colorado, and how they were done 35 years ago around Chicago (before I moved west). I've seen the blue sprayed foam on television, on the Holmes on Homes Show, but if it is used around here I haven't seen it. Here attics are mostly blown with fiberglass in a new build, though the big box stores sell cellulose as well --- homeowners usually blow that into old house attics that weren't insulated prior to WWII. Unfaced fiberglass batts are the second most common approach, usually R30, but as high as R45. Here, if one goes to Home Depot or Lowe's, they will never find faced insulation recomended for attics. You can now purchase fully encapsulated batts that make the installation more pleasant, but the film around the fiberglass is not a barrier. I don't know if building codes preclude vapor barriers at the lid --- I just know that standard practice does. Maybe it has something to do with the fact that we're a dry, high plains climate. I know some building engineers, so will try to remember to ask one of them. I used to work in the aftermarket home products field, installing sunrooms and the patio rooms that are basically styrafoam panels with skins. Condensation was always an issue with them, so I tend to prefer erring toward the less moisture tight side. I only use rockwool to insulate basement ceilings for sound (because it is so dense) and as chinking for fireblocking. Otherwise, it is mostly used in commercial construction here. I'm a residential contractor.369Views0likes0CommentsRe: Total Rebuild of a 1979 Dodge Class C
oldtrucker63 wrote: I do believe that the outer metal will let the inside walls breath, And lots of air will get inside through the old windows and the door as well as top vents, Inside the walls will get lots of air through the outer skin. Just so you know, O.T., when I say "structure" I don't just mean it it the technical sense. I mean the interior too, the point of building the structure proper --- the "efficient cause", so to speak. The part you want to enjoy, and I don't think that you'll seal it too tight and suffocate the family -- or that the pilots will go out and gas them. The truth is, an RV is a pretty small box to heat or cool, so the benefits of insulating, vapor blocking, etc., are probably pretty marginal when it comes right down to it.369Views0likes0CommentsRe: Total Rebuild of a 1979 Dodge Class C
oldtrucker63 wrote: lzasitko wrote: coloradohoosier wrote: I'm not sure if you want it all air tight. One thing I haven't seen mentioned when talking about insulation and vapor barrier in houses is that ceilings always use non-faced insulation. You want excess moisture and humidity to exit the structure (this is also partly why attics are vented at the soffits and up high). Your roof ia already a sealed membrane, so you might be best off if you end your vabor barrier six or eight inches from the top of the walls, intentionally allowing a place for vapor to exit. I can't say for certain, but suggest you do more research before sealing it all too tight. I'd hate to see you end up with unwanted water condensation inside after you're all done. YOU WANT IT AIR TIGHT! When building a house or a motorhome your worst enemy is air movement or air infiltration. If you can stop air from coming in or going out it is easier to heat or cool. The plastic is a vapour barrier same as in any house and is must be placed on the warm side of the wall as this is where moisture will condense. Insulation does let some air movement (batt insulation) which will help keep things dry. The Roof or exterior of most structures are not air tight. Houses these days are wrapped in a fabric (like Tyvek) which allows moisture to escape, but resists water penetration from outside. Even metal siding is not completely air tight (you still have joints or overlaps). I think your right, And Like coloradohoosier has said there needs to be air movement to allow moister humidity to exit the structure, In a house the attic is vented to allow this air movement, In this old dodge RV the outer metal siding allows this air movement, Only I believe the air inside of a RV should not be allow to reach the outer walls, The metal skin will let the air move to dry any condensation on the metals inter side and this should be the only place that condensation will gather as long as the air inside the RV is limited to inside the RV wall, The air inside the RV, AC or Heating should not reach the outer skin because this is what causes condensation, I believe a RV is a bit different than a house, I suggested more research, OldTrucker. I don't know for sure what the best vapor barrier application is for an RV. I do know for certain that Izasitko is mistaken regarding houses though. I'm building contractor. Faced insulation has a built in vapor barrier --- that's what the facing does. It isn't really the most efficient vapor barrier, but it is the most labor and cost effective, so is the standard approach. An alternative is to install plastic over the studs after insulating with non-faced insulation. Either way though, only walls (and crawlspace floors) get vapor barrier. Ceilings are always allowed to breath --- they always get non-faced isulation and no vapor barrier --- and air movement above the insulation is encouraged through venting of the attic, or the rafter cavities in the case of a vault ceiling. If a house is wrapped too tight, moisture will collect between the drywall and the vapor barrier, causing the fasteners to rust and the drywall to fail. Besides that, if a house were too tight the pilot lights and gas appliances would burn up the inside oxygen, and breathing occupents would consume it as well! It would take your family a while to breath up all of the oxygen in a house, but not that long in an RV. "YOU WANT IT AIR TIGHT!" is certainly wrong. Newer houses, because they are tighter than old ones, now bring outside air in for combustion in the furnace and water heater. An RV is somewhat different, I'm sure. Most people don't even use them when temperatures are low enough to freeze the water tanks. The windows are also less efficient than modern windows in houses, so undoubtably there is infiltration there, and through the rooftop air if you have it --- as well as in the cab area (vans and cars aren't airtight.) The main thing I thought of when I suggested more research was the issue I pointed out about drywall and fasteners. I'd hate to see you finish your build, then find that moisture collected in your paneling, creating mildew, mold, or a musty smell. If it were me doing the build I would research the matter thoroughly, or not use vapor barrier along the top of the walls to be safe. Your siding will allow moisture transfer, but your roof will not (unlike a house roof which is vented). You don't really have to worry about your heating/cooling bill like in a house, because the RV is so small, so concerns about it being completely tight for that reason are largely unfounded. That's my 2-cents --- remember what you paid for it.369Views0likes0CommentsRe: Total Rebuild of a 1979 Dodge Class C
oldtrucker63 wrote: I think this plastic is about 6 mil also, I have been overlapping the ends and same at the top where the wall meets the ceiling, I think this will seal everything air tight, I never thought of using Acoustic sealant to seal them I wished I would have though but its to late for that, For the most part, I can still seal it at the floor and I will do that, I'm just trying to get everything air tight. I'm not sure if you want it all air tight. One thing I haven't seen mentioned when talking about insulation and vapor barrier in houses is that ceilings always use non-faced insulation. You want excess moisture and humidity to exit the structure (this is also partly why attics are vented at the soffits and up high). Your roof ia already a sealed membrane, so you might be best off if you end your vabor barrier six or eight inches from the top of the walls, intentionally allowing a place for vapor to exit. I can't say for certain, but suggest you do more research before sealing it all too tight. I'd hate to see you end up with unwanted water condensation inside after you're all done.173Views0likes0Comments
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