Wall "studs" attachment

[JohnEd]

John,

Could you share some info about your spray foam adventure, please?  It looks like you didn't spray the center section of the roof.  And, the depth of the foam is what.... 1.5 inches?  What kind of outfit did your foam spraying and where did they do it and what did it cost?  Did you make a comparative estimate between spray and board?

I managed to get 4.5 inches in the overhead of a S&S and with the windows sealed and 1.5 in the walls that thing is like a thermos bottle.  Get all you can in your overhead space as the roof is the main are for heat loss and the windows aren't far behind.  Did you install double pane and E rejection windows? 

You being in Nevada and all brings that stuff vividly to mind.  Did you insulate your water bay yet?  How about the overhead in all the bays to get some floor insulation?  Even tiny holes in the front are monster air leaks with the bus moving and almost nothing can cool or heat the front with leaks....stuff you already know I'm sure but worth carping about given the number times it comes up.  Unfortunately, with buses already built.  Look at the buses with roof airs built over the drivers seat to augment bus drivers air in some cases.

Again, your workmanship looks way above par and better than I could do at least.  Thanks for sharing.

John

[Jriddle]

John

I used foam kits I purchased on the internet. I used about two full kits and had one that didn't work very well. (Long costly story) These kits run around 5 to 6 hundred. By using these you can plan as you go. When you have it hired done  you need to have all the stuff done in the walls before hand. I didn't use insulated windows. I figure I can install at a later date if I find it necessary. I insulated the box my water tanks are installed in but have not insulated bay yet. I put 1 1/2" of insulation in the floor. I used fire resistant blanket in the bedroom and foam board in the rest of the floor. This has made my headroom less but we are vertically challenge people.

John

[Jriddle]

Two More

[Jriddle]

John

I am doing the ceiling now. It will have about 2" of foam. I found it hard to spray around all my wires and tyring not to over fill the space too much. ( less mess trimming) Some areas have more than two inches and others a little less but more than 1 1/2".

[JohnEd]

John,


I had some reservations about how you would pull this off and what the outcome would be.  No more.  You are an inventive and talented designer and craftsman.  Yours is a superb job as far as I can tell.  Congratulations!

The key word in this adventure is ALWAYS plan plan plan and plan some more.  They put the floor down without much thought other than underlayments and insulation but from there they want the builder to know what he will be doing way out down the road in the future.  What I see most do is put masking tape on the floor to outline isles and appliances and built ins.  Then they mock up the cabinets and everything in three D with cardboard.  Finally they lock themselves in the bus for a few days to REALLY eval how everything works.  Little exaggeration there LOL.  But close to the truth.  You seem to have started building first.  That it is working out so very well for you I assume that you have an intellect that considers and remembers all alternatives and decisions and design.  Great work.  And thanks for sharing your adventure and proving "To each his own" once again.

John

[Bob Belter]

Ahoy, BusFolk,

One thing not mentioned is the importance of trying to avoid having (exposed)fasteners inside which go into the metal structure of the bus.  Thermal problems --  with the cold fastener condensing moisture, and wetting the plywood. 

Try to use firring strips which can fasten either on top, or onto the sides of the structure, and then screw your plywood onto the strips.  Then the thermal path is avoided.  They don't need to stand out at all (by hanging them on the side) if you want to maximize space.  (On my Eagle-01) I firred out 3/4" on the sides, but in the bedroom, my 1/4" overhead plywood is screwed directly to the steel structure, and I do have condensation.

I'd suggest inside, a layer of visquine (sp?) as the last thing inside your plywood.  That way, you will help to keep the humidity level in the space between the plywood and the structure and skin lower.  Some ventilation into that space would even help  --- ie  --- a bit of bleed from your air compressor (if you have a compressor air dryer).  Would not be hard to do on a new build. 

These bus conversions last a LOOONG time, and anything you do to make them last is important.

Enjoy   /s/   Bob     

[chev49]

i'd use tyvek if i was gonna visquine something...just a tad stronger

[artvonne]

  One thing not mentioned is the importance of trying to avoid having (exposed)fasteners inside which go into the metal structure of the bus.  Thermal problems --  with the cold fastener condensing moisture, and wetting the plywood. 

 Or stay south during the cold winter months, which would have the additional effect of keeping the Bus out of salt. Win win situation

 Im more concerned about the outer skin sweating against the insulation. And filling the frame tubes with expanding foam, is it possible this could lead to internal corrosion, perhaps rapidly? I have this fear of it being to a Bus, what fiberglass was to wood boats built before 1960.

 

[MEverard]

Art

Good comment about about the condensation between the shell and vapor barrier. You don't want to create a dew point that will rot the shell. You really have to be careful how you handle that application. Visqueen or something plastic does not breathe and can make the situation worse.

Mike

[JohnEd]

I have seen pics of  conversion up in the icy north where there were 'ice blossoms" or ?Buds" or "Flowers" all over the interior walls where ever there was a screw UNDERNEATH the paneling that was glued on the studs.  I thought it would make sense to sink the heads of the fasteners down a 1/4 inch.  That comment about screwing the fir strips to a separate board the was attached to the side of the rib was a gem.  I sue never had that take the short trip "cross my mind".  Thanks for that.   fully expect to never be anywhere where the temp might fall to 20 below.  Never!  But every little bit helps and a reduction in thermal conductivity yields comfort and fuel every time and forever.  Thanks for that tip.

John

[artvonne]

   The only real rust ive found inside the wall was where some moron drilled holes to hang a sign on the outside. Water got in, soaked the fiberglass, and the constant wetness put some rot on one of the diagonals. Im not finding any issues anywhere else.

  Im going to take my time studying before I decide what kind of insulation to go with. Lower R values would win out over the potential for rust, rot, and mold.

[artvonne]

I have seen pics of  conversion up in the icy north where there were 'ice blossoms" or ?Buds" or "Flowers" all over the interior walls where ever there was a screw UNDERNEATH the paneling that was glued on the studs.  John

  Thats a harse environment John, and there isnt any way to stop that effect 100%. Its happening inside the metal walls everywhere too. I was just back up in Minnesota for our sons wedding, and we noticed another establishment we frequented was gone, tore down for something else going in. And somewhere along the way it dawned on my how very few buildings last more than 50 years up there without the foundation cracking and busting up. I used to marvel (frown actually) how the tools inside my tool cabinet would frost up and sweat when I turned up the heat after it had been sub zero. Or why I found water drips on cars in the garage (roofing nails that come through the sheathing, they frost, sweat,drip). The only way to prevent that kind of sweating and condensation is to stay out of that extreme climate. If you lived up North a while, sooner or later you would see your sliding patio freeze shut, from the frost that forms along the track and on the metal handle. Its just got to get good and cold and stay that way a while. Then the ice melts and stains the wood and carpet, rots the floor, makes linoleum peel up, etc..