The flooring in the 109 is a interesting program. I am in the process of replacing one. Power washing is a good way to clean the inside walls. But I know on my 109 the reason the flooring was toast was due to the fact that it has no way to drain any water the gets into the inside of the box. There are no drains at all in the steel sheeting under the wooden flooring. And it is water tight. So whatever water gets into the box must just dry by evaporation. I do not know maybe they added drains at a later date but as I said my unit has no drains at all. When I removed the under floor metal the top under the wood was a total rusty mess but the underside of the same metal was perfect. You can bet when I lay down the new flooring it will have drains built in. Today I will be laying down the first layer of new flooring. In the first picture you can see the under wood flooring tin that I took out. Notice that the piece to the left with the undercoating on it is in good shape. While the larger piece that it is sitting on is actually a scaly rusty mess as it is the top side of the same under wood tin. The second picture is how the floor area looks now before I add some 3/4 inch marine/green treated plywood today. Then on top of the 3/4 inch ply goes 1 1/2 inch of high density foam (routed out to compensate for the fact that the wheel wells will be about 1/4 inch higher than the 3/4 ply). And on top of that will go a 1/2 inch of regular plywood and carpet on top of that. Yes I live in cold country and want to use the unit in the winter.
It is a 1970 rig for the earlier question. Congrats on the new 109 also.
Your removed flooring was a great shot by the way. It is very simular to semi trailer flooring and crossmember set up. I probably will go back in with oak trailer flooring but not the 1 1/4 that is noramall used - seeing as this has the wheel whells in it. After pressure washing out the interior it was a lake in this one also - floor drains are in the future.
We also use a product called FLOOR RESTORE in our older trailers. If you prep the floor and then lay out this product - be sure you never have to access the floor ever again. It is an epoxy clear coat that is very like polyurathane - it hold with the grip of God (no insult intended).
Been reading and looking at the pics of other conversions and just uterly amazed and what this unit has the possibility to become - thanks to all for their posting by the way - great job - salute.
I bet you are correct zout in your comment on the look of the cross members. The data plate on my van says it was built by Superior Coach and they have a lot of experience with buses/trailers. The cross members are on a 12 inch center. One of the potential problems we have in my area is that they use salt on the roads in the winter and even the slightest bit of water/salt getting to closed spaces is a real problem. After I got the wood off of the floor I notice that there was some indication that water had been getting in by running down the inside of the wall and then getting under the wood flooring. So I am going to make sure that should that ever happen again there are drains below the walls. I have sealed all the seams and rivets etc already.
maccus - Just walked outside and measured one of the trailers we are installing interior panels in and scuff - the crosmembers are 12 in on center and here is a pic of the floor screws we use - these take 1 1/4 oak flooring - after getting the flooring out (hardest part) lay in the new tongue and groove - drill 1/4 in hole just to the outside of center and run these in just a little past countersink - you can always use trailer flooring crack sealer (epoxy) to fill over the screws if you never want to access the screws again. I am sure there are others in the field as well that know these products. In containers - the flooring is 4x8x1 and is extremely hard - might even use this in mine when the time comes and then lay an overlay on top of it.