Floor removal?

[artvonne]

  So I been out guttin the Bus, im basically down to an original MC5B Bus with no seats. I searched but could not find anythng specific to an MC5, but before I do anything crazy, will all the plywood floor just come up? Does all of it need to come up? Its a bit soft around the right front wheel well, and there is a dip running transversly near the floor vents. But from there back the floor appears in good solid shape.

  What I thought of doing was rip up the original rubber floor, tear out the wood taking only whats bad, and/or what gets me into the duct work, etc. Replace with marine grade. Overlay with 1/4" foil back pink foam, then 1/2" ply marine grade sub floor. I then plan to put 1 inch foil backed pink foam under the floor.

[JohnEd]

All great ideas from what I have read.  Isn't the floor a functioning member of the frame rigidity?  I think I read once that you can't install "pieces but must go with full sheet 4 X 8 but I offer that as a discussion point.....I don't know.

The sheeting you want to install if you replace it all is tongue and groove.

After you pull the rubber floor you will have to put somthing in there to get the floor level again from side to side.  Consider taking it up with care and re laying it on the new sheet of ply.

A 1/2 inch layer of foam is a great idea.  Use the Polyisocynurate(?) as it is superior to everything except hot spray foam.

Consider using spray foam in the roof of the bay...under the floor.  You can get it thicker, it insulates much better AND it will quieten the interior.

Install a layer of 1/16 inch lead sheeting on the first floor layer.  This will quieten down the interior.  As will spray foam in the walls.....a must, really.

Have you pulled the inside panels?  The vert steel braceing that runs from the floor to the ceiling and besides the windows almost always need a lot of attention.   Replacing the entire brace and welding in additional bracing seems common and much needed.

1/2 inch ply screwed and glued with Silka Flex.  Rubber flooring material. 1/16 inch lead, 1/2 inch foam board, 1/2 inch ply.  All new wood tongue and groove and glued and screwed. 

Most have pulled the entire floor and  started from scratch.  I would leave as much of the good floor sheets as I could.

For the LOVE OF PETE don't neglect to sweep, vacuum and pressure spray that filthy tunnel that runs down the center under the isle.

Just what I remember off the top,

John

[Jeremy]

Using marine grade plywood would be complete overkill and would cost thousands of dollars. Exterior grade is more than sufficient.

Although the idea of incorporating a layer of foam between two sheets of plywood is attractive, I'm not sure 1/4" of an inch of foam is much of a benefit for all the extra work and complication. No point using foil-backed foam in that situation either (heat will be lost through the floor by conduction and a small amount of convection. Foil prevents heat loss by radiation, and there wouldn't be any of that).

As has been mentioned, insulating beneath the floor is probably a better bet


Jeremy

[artvonne]

Isn't the floor a functioning member of the frame rigidity?  I think I read once that you can't install "pieces but must go with full sheet 4 X 8 but I offer that as a discussion point.....I don't know.

  I dont honestly know either which is why im askin. I know on GMC's its part of the structure. I see all the pics of MCI 7's, 8's, and 9's with the floor pulled up, kinda assuming/hoping the old 5's are same?

  I will price lead sheet, if its not out of this world in price or weight I'll consider it over the engine and front wheel wells. But I may forego the spray foam and use sheet foam instead, mainly due to cost and logistics, time. I also want to keep the weight down, and lead sheet doesnt sound so light to me, lol.

  Are you saying the original plywood flooring is tounge and groove??

  And what are you meaning about leveling side to side??
 

 

[RJ]

Paul -

MCI's of your vintage are what's known as a "semi-monocoque" construction.  Used right up until they introduced the "E" models, when they switched to more of a "birdcage" frame.  Very similar to a GM, but slightly different.  For example, the GMC hangs the engine from the rear bulkhead and the roof, whereas MCI uses a cradle tied into the rear undercarriage.

The bulkheads on both sides of the axles, plus the ones separating the baggage bins, provide some torsional rigidity, and they help keep the coach "square."

So does the floor.

Thus the need for full sheets of plywood.

If you're going to pull the floor, then you need to block up the coach and make sure it's completely level front-to-back and side-to-side.

Small patches should be ok w/o all the blocking.

Check out "Gumpydog" Craig's site for lots of exposed MCI chassis help. 

FWIW & HTH. . .

[JohnEd]

Isn't the floor a functioning member of the frame rigidity?  I think I read once that you can't install "pieces but must go with full sheet 4 X 8 but I offer that as a discussion point.....I don't know.

  I dont honestly know either which is why im askin. I know on GMC's its part of the structure. I see all the pics of MCI 7's, 8's, and 9's with the floor pulled up, kinda assuming/hoping the old 5's are same?

  I will price lead sheet, if its not out of this world in price or weight I'll consider it over the engine and front wheel wells. But I may forego the spray foam and use sheet foam instead, mainly due to cost and logistics, time. I also want to keep the weight down, and lead sheet doesnt sound so light to me, lol.

  Are you saying the original plywood flooring is tounge and groove??

  And what are you meaning about leveling side to side??
 

 

The rubber sheeting floor covering is only glued on the ends...front edge and back edge.  It is a 1/8 or possibly 1/16 inch thick.  There are stainless channels that run front to back that are for mounting the seats.  if you pull the ribber you will have a distinct edge in the center of the floor from front to back.  If you pull back the rubber after carefully separating it from the floor in the front you can simply lay it back down and re-glue it and have the floor level again.  Long ago everybody seemed to be hell bent on pulling the SS rail but those guys were replacing the entire floor.  It may be that you need to pull all the floor to get at that center raceway that was the return aoir for the AC and heat.  The first thing you do is commit to cleaning that and then replace all the floor if need be to accomplish that. 

The lead is heavy.  That is why it quietens so well.  BUT, with a layer of 1/2 inch foam you will also quieten the floor.  Someone here that has done these things should add something.

Foam board is more expensive and takes longer to install and doesn't work as well.  The silver backed Polyfoam board is the best of the rigid stuff.  If yo foam the underside with hot foam you should make it reasonably quiet and insulated..  You can economize in a lot of places but insulation is not on the list of allowable.  Whatever you can do to reduce the heat load and help the AC is just so much of a priority.  You pay for the fuel in the winter and you SUFFER with inadequate AC in the summer.  You might pull out the woolens for a furnace problem but you will evacuate in the summer sun if the AC fails and you won't have to be in Death Valley or Gila Bend to get in trouble.  You need 4 inches of roof foam and the wall thickness plus the firing strip deapth.  Lots of data in the archives and Gumpy and Ace and many others have written extensively.  INSULATE and do it with spray foam.  It used to cost 12 to 1400 to do a bus and they would trim it all down for you for a 12 pack.....sometimes.  The beauty is that those guys are mobile and they will do you while they are in town doing walk in refers/freezers.  Also, if you get a good quote from a shop a ways away you might consider driving to them.  Spray was always cheaper and I hope that hasn't changed but even if it has gotten relatively more spendy I am sure most would still advocate the spray.  Get well versed on the subject and if you decide to go that way then run this flag back up the pole cause there is tons of more stuff in details.  Also, where good deals can be had and what shops to avoid. 

They always put lead on the engine bay walls at least and the spray foam over that will be many inches deep to ward off engine heat from making the bedroom unbearable for the hour after you stop.  If you use spray foam then the lead becomes less of an issue.  I have read where guys with MCI 9s said that after foaming they could not hear the engine while going down the road.  Start a new topic on insulation and get the advice of those that have done this recently.  Prices and products change and maybe it needs rehashed to your specific benefit....and everybody else that reads the board.

If I knew the answer to some of your flooring questions i certainly wouldn't horde that info.  You have put your finger on exactly one of the many things I have no info on.  Please don't hold against me what I haven't done.  Start a new thread and ask for guidance on that specific topic.  You will get better results.  As this goes on you will undoubtedly get better at the specifics of what you need to know.

Pleasant journey,

John

[Flatspot]

I've used mass loaded vinyl for sound deadening in many applications including on the floor of the 4104. It is made specifically for sound attenuation applications. It comes in an 8' wide roll and varying thicknesses. It is heavy like you would think lead sheeting would be but it is much easier to work with. It also doesn't carry the 'red flags' that lead carries for the environmental side of things (I'll try not to get side tracked on this). I purchase it from an industrial insulation supply company. It can be glued to the surface with industrial glue and anything attached to it in the same way. If you cut into a pattern and heat it with a heat gun, it will form to a compound surface like a wheel well or firewall.
That is what I would suggest to at least investigate for your application.

LJ

[bevans6]

You don't have much headroom in a MC5, so if you aren't planning a roof raise try to keep the floor as thin as possible.

Brian

[artvonne]

  Thanks for all the info guys, lots to think about. I plan to not have roof air, so the ceiling will be clear of obstructions to club my head on. I saw yesterday that I could stand on a 3 inch block and still clear the cieling, so 4 inches in the roof would be doable.

  In the back, my plan is to build a sub floor up to the height of the wheel wells, and have a queen size bed. I'll probably hinge the bed frame along the left side so I can swing it up to reach the engine access panels.

  I had somehow imagined I would have the insulation done and be ready to start framing walls within a week or so. Reality is sinking in that preparing for two trips to weddings up North are going to totally sidetrack things, which ultimately might work to my advantage by giving me more time to choose what I want to do.

  I'll look into having it foamed. I wasnt going to, but thinking back about last summer up north and the killer humidity, I definetly want it cool. But I also like fresh air. I would rather be a bit warm and have fresh air than cool and closed up.

[bevans6]

Definitely think about things, particularly at the back.  We had a center queen bed, and both of us tripped on the wheel arches and hit our heads on the ceiling, since the slope of the curved roof makes headroom quite bad at the sides of the bus.  raising the floor would make it that much worse.  I tore that out and installed twin beds with a center aisle, less romantic but a far more practical solution.  Also Peninsula sliding screened windows in the bedroom.

Brian

[Mex-Busnut]

I would only make one small suggestion: Once you have your ceiling bared, take a high-pressure water hose from the outside of your bus' roof and check for any water leaks in the full length of your rooff BEFORE you do your spray foam. Once the foam is in, fixing a leak is no fun.

My 2 pesos' worth.

[artvonne]

  I suppose we could use the cardboard design studio concept, put a real matress back there up on some blocks, and see how we like it.

[buswarrior]

Never heard a busnut complain they had too much headroom...

Save yourself the embarrassing admissions afterwards.

Preserve headroom or raise the roof.

happy coaching!
buswarrior

[artvonne]

  Right now I have nearly 4 inches of clearance between the top of my skull and the center of the foam backed naugahyde ceiling, with my shoes on. I will not raise the roof, but I also wont have roof airs danglin down in my ambulatin path. I'm 6'1, and as long as I can walk through unemcumbered, the rest of the tribe will be fine. It appears there is about an inch and half between the roof and original ceiling. If I do go 4 inches, that only intrudes two and a half inches, still leaving me headroom. I can live with that. And if I can get two inches under the floor I should be good.