gut floor or cover floor?

[carneybus]

So I have ripped out everything in the bus. seats, overhead storage, the lav. when I ripped off the ac skirts I noticed the floor being weak over the driver's rear wheel wells. any thoughts on either re doing the floor or just going over it with new ply? 

James

[pabusnut]

If you have everything out now, you should replace the floor as you will not have another chance, and will regret it forever.

Just my thoughts!

PAbusnut
Steve Toomey

[carneybus]

Thanks Steve.

I Know I have to do something with the floor. but I've read about how it keeps the bus "square" and I'm not really in a place where I can keep the bus level. I currently have a shed full of parts and things to go inside the bus. but this floor is really getting to me. I know if I take the floor out I want to take the seat rails out. I just don't see the need for them.  I would love your thoughts and ideas.

the bus is a 1980 MCI MC9 it has an 8v71. its an old church bus.

[Darkspeed]

I leveled mine on solid concrete blocks and then used a case of 4" steel electrical box covers as shims to do an exact level on all four corners with a laser level.

[Debo]

I ripped up the old floor out of my '81 MC9 and replaced it with 3/4" plywood. I wouldn't worry about the structural stability that the floor is providing when parked. While I'm sure it doesn't hurt, the frame and bracing under the floor are what's keeping it "square." The seat rails come out reasonably easy with a cut-off wheel on a grinder. They're tack-welded to the frame about every 8". After I cut the welds, mine came up basically in one piece. After I had the frame nice and flat and everything under it repaired, I used self-drilling screws to put the floor back in. It's a big job, but not a difficult one.

[carneybus]

Debo.

when you took the rails off did you cut the ply to fit the sections or did you use the whole sheet? I've been looking at both options and if I can do it i'm going to try to do whole sheets.

[Debo]

If I remember correctly, I ran the plywood lengthwise. Anywhere two sheets meet, the gap should be resting on a frame member so it's supported and can be screwed to it. The seat rail is tacked to a long frame member, so I think I cut the wood to the dimension from the wall to halfway across that frame member. I did this on both sides, then measured and cut the middle piece.

There's a member of these boards named Craig Shepard. He's got an amazing website where he details a lot of the work on his MCI. He may even chime in after reading this. Just Google "gumpydog" and go to the Shepard family website. It's an amazing storehouse of information. He's got tons of pictures and description of how he replaced his floor. Great stuff.

[pabusnut]

James,

I have a GM 4905, and there was no way to put the plywood back in like factory, since some of the sheets were 5' x 8' and were "rabbited" under the sidewalls!!  I ended up using a lot of plywood, but all my joints are on the bay walls and stringers.  I leveled the bus before I started, but only took out the floor over one bay at a time.  My floor was weak at some places, and at most of the others it was bowed upwards from the force of the torsion springs that lift the bay doors(now eliminated--replaced by gas struts).  The original floor was only 5/8" thick, and the replacement is now 3/4".  I also took out the seat rails which is the hardest part of the job in my opinion.  That seat rail is probably the toughest metal on the whole bus!  It must be some sort of stainless-manganese alloy.  Under the new floor I also added some angle iron stiffeners perpendicular to the length of the bus to stiffen the spans over my 70" long bays where previously there was none, as it was under the seats.

Think of the floor as your foundation.  You wouldn't build a new house on sand!

Steve

[Dawgs]

James, Gut your floor.  You won't be sorry.  Most of your longitudinal stiffness comes from your sidepanels, not the floor.  While you have the floor up is a great time to dig out old nasty insulation and clean your return air ducts.  I will also tell you that this is one of the nastiest jobs on your build project.  I would also cut out he seat rails.  Also a great time to inspect areas that you will never see again.  Take pictures of and/or make drawings of all stringer locations that once the floor is back down you will know their locations.

[scanzel]

If you use 4x8 sheets of tongue and groove heavy duty 3/4" plywood you don't need to put the seems on the cross braces, just glue and butt them together and screw to bracing. Since a 9 is only 96 wide you should be ok putting them cross wise but will need to remove the seat tracking. I have a 102 wide and went cross wise a little gap along wall but wall siding filled it up.

[Oonrahnjay]

     I had a couple of small places around the edge of my downstairs floor where rain would seep in and the plywood (some kind of fir or other evergreen, about 1/2" thick) was soft when you poked it with a screwdriver.  "OK," said I, happily "I'll dig out the rotten places and patch them in".  Yeah, right.  Within three days, the only part of the original floor left was the front door passenger entry ramp. 
     I since my bus is a "transit", there are many bumps on the floor.  I had to work around the wheel wells, which protrude up into the downstairs area (they were originally used as plinths for seats) and, of course, the stairs.  I also closed in the original front passenger entry door (that door would just open onto the street when used on N American streets anyway) and extended the original driver's compartment floor across; this way, the driver and The Management are side by side as you'd expect for two front-seat-area occupants.  I floored in that part with a single sheet of plywood, cut out for foot pedals, steering column, dashboard profile, etc.  Then it got interesting. 
     What I'd do is take a medium sized piece of cardboard box (like a refrigerator box) and put one long area on the place where I wanted a seam.  Then I'd take smaller pieces of cardboard and overlap the big piece but push the smaller pieces into the corners or up against the previous piece of ply.  If the corners weren't square, i'd take two pieces and align one with one wall and the other with the other.  When it was all down and the pieces of cardboard fit into all the corners and crannies, I'd tape the whole thing together then take the cardboard out and put it on a piece of "marine 3/4* plywood", outline it, and cut it.  The ply would fit all the complex angles and dimensions.  And I didn't have to measure anything. 

[Jim Eh.]

You will be glad you replaced the floor when you find critters have homesteaded in the insulation. Good time to change the insulation out with something better than 1" to 2" (maybe) of glass fiber insulation and fix any small rusted areas there might be.

TIP: Add in some random runs of electrical wiring (cat5, telephone, 14/2 electrical, etc.) front to back while the floor is out plus one run of 2" ABS plumbing tube for any future additions you may want to make.

[Paul]

We removed all the floor, wire brushed all the steel and repainted. A lot of the insulation was wet and the steel over wheel wells was rusted out. Replaced them with stainless steel.


i recommend replacing the floor the same way the old wood floor came out. Had a friend that tried the toung and grove and did not hold up well at all. You can add a lot with the floor out. Go to www.incredibus.com to see repairs we made.

Happy Bussin
Paul

[krcevs]

I'm replacing the entire floor in our 4107. Time consuming but well worth the work as I will 1) know our bus inside and out and 2) have a solid foundation to build on.

Ken

[Scott & Heather]

James, I agree, gut the floor. We did on our 9 and have never regretted it!  Hard job, but so rewarding to have fresh wood down there: we used tongue and groove ply. It was perfect for the job:
View the link in my signature and you'll see photos of our floor removal and replacement procedure.


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