Supplies and materials
This van plan and build has taken place during the COVID pandemic. While these are unique times, some of the thoughts would probably still apply after we're more or less back to normal. Keep in mind that I'm a retired person and can work on the build at my convenience but having the right tools and supplies on hand make for a much more efficient build. Once we decided to proceed in December 2020 and placed an order for a van, I started watching YouTube videos on specific build aspects and ordering/buying supplies and materials. This allowed for a couple of things:
1) Building anything like this takes a lot of consideration. Even though there are loads of YouTube videos out there, you need to wrap your brain around your process for your own build. Each individual stage of the build has multiple things to consider in terms of what is needed and what process to follow. It will be different for you due to your circumstances; your personal skills, tools on hand, even if it's the same brand and model of van the year, features, and structures will be different. Doing a lot of thinking ahead of time while you are waiting for your van to arrive (or searching and waiting for availability if buying used) will save you 80% of the time later so you won't hold up your build process. Really get into the detail and visualize yourself going through any particular build aspect and then get the things you know for sure you will need ahead of time.
2) Some of the components will take weeks or months (even during non-COVID times) to find, order/buy, and arrive. Some examples: The fridge I wanted took over a month to ship and clear customs. Windows took 2 months to be made and shipped. I'm still waiting for the awning as we are working through the shipping and customs bottle neck. Some systems will take multiple items which can only be ordered sequentially, e.g., plumbing (what shower base?, what drain type fits?, how will the drain systems integrate?, what heating system?, etc.); electrical (what batteries?, switches that will be needed, cabling, inverters and charge controllers, integrating with the van system, wire connectors, what appliances will you want?, etc.) If you wait until you have the van and are building, then ordering various parts (even really minor ones) each step of the way can really add loads of time to your build as you might not be able to finish a significant system without something quite small. That in turn delays everything else because you really do need to follow a particular order to be efficient.
This van plan and build has taken place during the COVID pandemic. While these are unique times, some of the thoughts would probably still apply after we're more or less back to normal. Keep in mind that I'm a retired person and can work on the build at my convenience but having the right tools and supplies on hand make for a much more efficient build. Once we decided to proceed in December 2020 and placed an order for a van, I started watching YouTube videos on specific build aspects and ordering/buying supplies and materials. This allowed for a couple of things:
1) Building anything like this takes a lot of consideration. Even though there are loads of YouTube videos out there, you need to wrap your brain around your process for your own build. Each individual stage of the build has multiple things to consider in terms of what is needed and what process to follow. It will be different for you due to your circumstances; your personal skills, tools on hand, even if it's the same brand and model of van the year, features, and structures will be different. Doing a lot of thinking ahead of time while you are waiting for your van to arrive (or searching and waiting for availability if buying used) will save you 80% of the time later so you won't hold up your build process. Really get into the detail and visualize yourself going through any particular build aspect and then get the things you know for sure you will need ahead of time.
2) Some of the components will take weeks or months (even during non-COVID times) to find, order/buy, and arrive. Some examples: The fridge I wanted took over a month to ship and clear customs. Windows took 2 months to be made and shipped. I'm still waiting for the awning as we are working through the shipping and customs bottle neck. Some systems will take multiple items which can only be ordered sequentially, e.g., plumbing (what shower base?, what drain type fits?, how will the drain systems integrate?, what heating system?, etc.); electrical (what batteries?, switches that will be needed, cabling, inverters and charge controllers, integrating with the van system, wire connectors, what appliances will you want?, etc.) If you wait until you have the van and are building, then ordering various parts (even really minor ones) each step of the way can really add loads of time to your build as you might not be able to finish a significant system without something quite small. That in turn delays everything else because you really do need to follow a particular order to be efficient.
Ladders and roof rack work
I don't know about you but I don't love being in high places. I'm not afraid - but I do know it's so easy to get hurt with a fall. That could be falling off from over reaching, the ladder not being secure and falling back if too steep, or the bottom kicking out if the floor surface doesn't have enough friction, e.g., a painted garage floor. If you're using an "A frame" ladder, it's really easy to have that topple over if you are using that alongside the van. There's also the problem of protecting the side of the van from scratches when using a ladder. Two things provide a good solution. 1) A sponge pool noodle. Cut two pieces anywhere from 12-24". Then make a vertical slice on one side of each length so that you can clamp one piece onto each ladder arm where the ladder contacts the van. This will protect your van metal from the ladder. 2) Large velcro straps. Loop a couple of these onto the top rung of your ladder. Place the ladder against your van and use the straps to secure the ladder to the roof rack on your van. This will prevent the ladder from falling backwards or from kicking out if you are leaning and reaching onto the roof of your van. This can also save you the embarrassment of having the ladder fall while you are on the roof and not having an easy way to get off!
I don't know about you but I don't love being in high places. I'm not afraid - but I do know it's so easy to get hurt with a fall. That could be falling off from over reaching, the ladder not being secure and falling back if too steep, or the bottom kicking out if the floor surface doesn't have enough friction, e.g., a painted garage floor. If you're using an "A frame" ladder, it's really easy to have that topple over if you are using that alongside the van. There's also the problem of protecting the side of the van from scratches when using a ladder. Two things provide a good solution. 1) A sponge pool noodle. Cut two pieces anywhere from 12-24". Then make a vertical slice on one side of each length so that you can clamp one piece onto each ladder arm where the ladder contacts the van. This will protect your van metal from the ladder. 2) Large velcro straps. Loop a couple of these onto the top rung of your ladder. Place the ladder against your van and use the straps to secure the ladder to the roof rack on your van. This will prevent the ladder from falling backwards or from kicking out if you are leaning and reaching onto the roof of your van. This can also save you the embarrassment of having the ladder fall while you are on the roof and not having an easy way to get off!
Cutting holes - air nibbler or jigsaw?
When cutting large holes in sheet metal for window openings there are a couple of tools to choose from. You can them in action on YouTube but here's what I found.
Air nibbler: This is a less common tool for most home workshops. It requires compressed air to operate. Some challenges included: 1) If there was factory insulation/sound deadening materials in the way of the cut, that had to be removed first. (Note: It is easy to remove if you use a heat gun and a putty knife - a putty knife on its own won't do it.) 2) It was more difficult to control and also more difficult to see exactly where you were cutting. 3) It left LOTS of tiny little crescent shards of nibbled metal everywhere. They are very sharp and get stuck in things easily - be sure you have the area well protected with drop sheets. So why use an air nibbler at all? If your cuts are in tight quarters close up against large metal ribs you might not be able to get a jigsaw in place because there's no room for the foot/shoe of the jigsaw. You can get around this by cutting from the outside but then you can't see where the ribs are if you're working with those as reference points.
Jigsaw: If I had open areas to cut with only minor bumps (small raised metal ribs) then the jigsaw was far easier to use. You can see exactly where you are cutting most of the time. Just use a high tooth count metal cutting blade (minimum 22 teeth per inch.) I think the blades I had were 32 tpi. Have the blade going at full speed but be sure to move slowly on curves and let the blade to do the work - don't force it as that's when the jigsaw will go where you don't want it to go because the blade will start flexing under the pressure. When cutting horizontally be sure to fully support the weight of the saw and keep the blade straight and unstressed. You may also put masking tape on the bottom of the foot so that the metal doesn't get scraped as you are cutting. It may sound counter intuitive but a heavier saw is easier to control than a really light one. The heavier one will be less prone to vibration and feel more controlled in your hands.
When cutting large holes in sheet metal for window openings there are a couple of tools to choose from. You can them in action on YouTube but here's what I found.
Air nibbler: This is a less common tool for most home workshops. It requires compressed air to operate. Some challenges included: 1) If there was factory insulation/sound deadening materials in the way of the cut, that had to be removed first. (Note: It is easy to remove if you use a heat gun and a putty knife - a putty knife on its own won't do it.) 2) It was more difficult to control and also more difficult to see exactly where you were cutting. 3) It left LOTS of tiny little crescent shards of nibbled metal everywhere. They are very sharp and get stuck in things easily - be sure you have the area well protected with drop sheets. So why use an air nibbler at all? If your cuts are in tight quarters close up against large metal ribs you might not be able to get a jigsaw in place because there's no room for the foot/shoe of the jigsaw. You can get around this by cutting from the outside but then you can't see where the ribs are if you're working with those as reference points.
Jigsaw: If I had open areas to cut with only minor bumps (small raised metal ribs) then the jigsaw was far easier to use. You can see exactly where you are cutting most of the time. Just use a high tooth count metal cutting blade (minimum 22 teeth per inch.) I think the blades I had were 32 tpi. Have the blade going at full speed but be sure to move slowly on curves and let the blade to do the work - don't force it as that's when the jigsaw will go where you don't want it to go because the blade will start flexing under the pressure. When cutting horizontally be sure to fully support the weight of the saw and keep the blade straight and unstressed. You may also put masking tape on the bottom of the foot so that the metal doesn't get scraped as you are cutting. It may sound counter intuitive but a heavier saw is easier to control than a really light one. The heavier one will be less prone to vibration and feel more controlled in your hands.
The Transit floor
For the most part, the ribs are level running up the middle of the van. They dip lower just a tiny bit when you get to the sides of the van. I found that 1/2" Auracoply from Home Depot goes nicely in between the ribs (but result in about 1/8" air gap between the bottom of the wood and top of the ribs.) I glued the wood slats down with Sikaflex 221. I ran out part way and used 291 for the front part of the floor. We'll see if there's a difference but both 221 and 291 get really good reviews online. On top of the ribs I applied strips of self-adhesive foam with aluminum foil backing. You can also get rolls of this material at Home Depot - it's meant for insulating ducts and water lines in buildings. This will provide a thermal break from both the wood slats as well as the foil foam. Heat transfers by convection, conduction, and radiation. So I'm hoping that the between the wood, the foam, and the foil, there will be a reduction in heat transfer through the floor. I also like the fact that there is still some open air under the floor so that if any moisture gets under the subfloor it can have an opportunity to evaporate. On top of this subfloor I'm using 2x6 framing lumber (which is really 5 1/2" high) to support the final 5/8" Baltic birch plywood floor. This will provide storage under the floor. I realize that this sacrifices some height inside the van but we are not tall people so it will be perfectly fine for us. I estimate there will still be about 6'4" of headroom in the van. I'll post an actual measure after we're done building.
For those of you running propane, diesel, or gas powered air heaters, running one air duct into that 5 1/2" storage space would give you a heated "basement" and also make your internal floor a bit warmer for walking/standing on. You could even put vents in the floor so the heat would go into the basement and then out into the van space (as long as you didn't have anything too smelly in the basement!)
For the most part, the ribs are level running up the middle of the van. They dip lower just a tiny bit when you get to the sides of the van. I found that 1/2" Auracoply from Home Depot goes nicely in between the ribs (but result in about 1/8" air gap between the bottom of the wood and top of the ribs.) I glued the wood slats down with Sikaflex 221. I ran out part way and used 291 for the front part of the floor. We'll see if there's a difference but both 221 and 291 get really good reviews online. On top of the ribs I applied strips of self-adhesive foam with aluminum foil backing. You can also get rolls of this material at Home Depot - it's meant for insulating ducts and water lines in buildings. This will provide a thermal break from both the wood slats as well as the foil foam. Heat transfers by convection, conduction, and radiation. So I'm hoping that the between the wood, the foam, and the foil, there will be a reduction in heat transfer through the floor. I also like the fact that there is still some open air under the floor so that if any moisture gets under the subfloor it can have an opportunity to evaporate. On top of this subfloor I'm using 2x6 framing lumber (which is really 5 1/2" high) to support the final 5/8" Baltic birch plywood floor. This will provide storage under the floor. I realize that this sacrifices some height inside the van but we are not tall people so it will be perfectly fine for us. I estimate there will still be about 6'4" of headroom in the van. I'll post an actual measure after we're done building.
For those of you running propane, diesel, or gas powered air heaters, running one air duct into that 5 1/2" storage space would give you a heated "basement" and also make your internal floor a bit warmer for walking/standing on. You could even put vents in the floor so the heat would go into the basement and then out into the van space (as long as you didn't have anything too smelly in the basement!)
How "permanent" to build for...? Build it to be deconstructed!
My tendency is to over build when working - true around the house and in the van too. Something I've learned though is that while it is okay for things to be built solidly in the van, always keep in mind that you want to build so it can come apart if you need to deconstruct. Case in point are the 1/4" baltic birch wall panels that are the finished interior in Redford. I had considered using brad or finishing nails to attach them to the 5/8" framing walls. Someone had also suggested to me that glue might be a good thing to use so that I could avoid the appearance of physical fasteners. Thank goodness I just used screws! They're small - 5/8" #4 (that means a "0" Robertson driver which is a pain...) There have been three occasions when I needed to take panels off in order to fix a problem. With the panels only attached with screws (even though they were painted over because I was "finished") it was easy to get to the underlying 5/8" framing. Once was to cut some material away to give wires more clearance under the paneling, another was to fix the trim because the cutline was not straight and didn't look good against the brown window frame, and today it was so that I could recut the bathroom wall.
Kreg pocket screws and building are fantastic for reworking things. You can take panels apart, cut/adjust, and then rejoin them. If you're careful with clamps you can also reattach them in a slightly different alignment if you want. Just realize there are limitations to this as the screws will want to go into already existing holes if you're not careful.
Also along the same lines, don't use thread lock with Plusnuts/Rivnuts. Months ago when I was first attaching panels to the PlusNuts in the van wall, I was thinking I didn't want screws to come loose so I used thread lock on a few of the 1/4" bolts. That was not good! When I had to take something apart later, that only caused the PlusNut to spin when I tried to reverse the bolt out because they were locked together and the PlusNut was not completely locked to the van metal.
My tendency is to over build when working - true around the house and in the van too. Something I've learned though is that while it is okay for things to be built solidly in the van, always keep in mind that you want to build so it can come apart if you need to deconstruct. Case in point are the 1/4" baltic birch wall panels that are the finished interior in Redford. I had considered using brad or finishing nails to attach them to the 5/8" framing walls. Someone had also suggested to me that glue might be a good thing to use so that I could avoid the appearance of physical fasteners. Thank goodness I just used screws! They're small - 5/8" #4 (that means a "0" Robertson driver which is a pain...) There have been three occasions when I needed to take panels off in order to fix a problem. With the panels only attached with screws (even though they were painted over because I was "finished") it was easy to get to the underlying 5/8" framing. Once was to cut some material away to give wires more clearance under the paneling, another was to fix the trim because the cutline was not straight and didn't look good against the brown window frame, and today it was so that I could recut the bathroom wall.
Kreg pocket screws and building are fantastic for reworking things. You can take panels apart, cut/adjust, and then rejoin them. If you're careful with clamps you can also reattach them in a slightly different alignment if you want. Just realize there are limitations to this as the screws will want to go into already existing holes if you're not careful.
Also along the same lines, don't use thread lock with Plusnuts/Rivnuts. Months ago when I was first attaching panels to the PlusNuts in the van wall, I was thinking I didn't want screws to come loose so I used thread lock on a few of the 1/4" bolts. That was not good! When I had to take something apart later, that only caused the PlusNut to spin when I tried to reverse the bolt out because they were locked together and the PlusNut was not completely locked to the van metal.
Working Under the Van
There's no substitute for space! When I started working on measuring and prepping for the gray and black tanks, I worked under the van at regular height on the floor. That was fine for sliding around and getting measurements. Making and trying out the cardboard models was also okay this way because they're really light! Once I had real polypropylene tanks make from the models, it wasn't so easy. It's a BIG van, so using a lift has it's challenges too. I had originally planned to put the van up on steel stands however that planned failed because the jack points on the van are very specific and quite small. We have big, medium, and small hydraulic floor jacks in the workshop. The only place I could get them in to use properly was for the front wheels. The rear jack points are very close to the rear wheels and with a DRW truck I couldn't get the jacks in place and still have a place to operate the hydraulic lever. In the end, I did put the front tires onto two 2x6 pieces stacked together. I jacked the rear up by using the Ford supplied jack (which was good practice anyways) and put each rear tire on a piece of 2x6. I found the jack not so easy to use. I ended up using a ratchet on the black tube steel that Ford provides (I couldn't imagine doing that in the rain or in mud...) After all of that it would probably be much easier to make or buy a set of drive on lifts for the rear tires and jack the fronts onto the 2x6 stacks. But then to drive onto the lifts you need the room and the van is 22 feet long to begin with! The extra 2 or 3 inches gained by lifting were absolutely essential. It made everything not only easier and more comfortable but some of the tank manipulations (I called it Tank Tetris) would not have been possible with the van at floor level.
There's no substitute for space! When I started working on measuring and prepping for the gray and black tanks, I worked under the van at regular height on the floor. That was fine for sliding around and getting measurements. Making and trying out the cardboard models was also okay this way because they're really light! Once I had real polypropylene tanks make from the models, it wasn't so easy. It's a BIG van, so using a lift has it's challenges too. I had originally planned to put the van up on steel stands however that planned failed because the jack points on the van are very specific and quite small. We have big, medium, and small hydraulic floor jacks in the workshop. The only place I could get them in to use properly was for the front wheels. The rear jack points are very close to the rear wheels and with a DRW truck I couldn't get the jacks in place and still have a place to operate the hydraulic lever. In the end, I did put the front tires onto two 2x6 pieces stacked together. I jacked the rear up by using the Ford supplied jack (which was good practice anyways) and put each rear tire on a piece of 2x6. I found the jack not so easy to use. I ended up using a ratchet on the black tube steel that Ford provides (I couldn't imagine doing that in the rain or in mud...) After all of that it would probably be much easier to make or buy a set of drive on lifts for the rear tires and jack the fronts onto the 2x6 stacks. But then to drive onto the lifts you need the room and the van is 22 feet long to begin with! The extra 2 or 3 inches gained by lifting were absolutely essential. It made everything not only easier and more comfortable but some of the tank manipulations (I called it Tank Tetris) would not have been possible with the van at floor level.
Cabinets and other building - 1/2" or 5/8" Baltic birch?
I've been using the Kreg pocket screw system (and now also expanded to a few other tools they produce) for several years now. I really like working with the system for both initial construction as well as "rebuilding" when needed. So my comments about what thickness of plywood to use for making cabinets is based on using the pocket screws for joinery. I've used 1x2, 1x4, 2x4, and 2x6 materials, 3/4" fir plywood, and true 1" boards to build many different things in the past. For this van build I've had the opportunity to add in both 5/8" and 1/2" Baltic birch for cabinet carcasses, doors, drawers, floor and wall framing, etc. The consistency and quality of Baltic birch is superior to the fir plywood that we get in North America. There's often voids or filler material in the fir plywood we get in our local stores. Because BB has so many plies for it's thickness, it is much stronger and stiffer by comparison. I haven't done any testing but the rigidity and strength of the BB makes the 5/8"BB feel like 3/4" fir plywood. When building a van using thinner material for the same strength for your build is always a good thing.
Benefits of 5/8"BB over 1/2"BB:
The 5/8 is much more forgiving in terms of tolerances. If you're not an experienced professional cabinet maker, the extra thickness of the 5/8 will allow more room for error when using the pocket screws. I'm pretty finicky and detailed when it comes to my finishing work, I work pretty accurately and feel I have pretty good skills with tools and my hands. That said, I still found times when joining the 1/2 material that there were bulges in some joins where the pressure of the screw passing through the pocket pushed the outside ply layers a bit. Maybe my alignment on those screws wasn't perfect? I don't think I ever had that happen with the 5/8. The 5/8 is also more rigid and dimensionally stable than the 1/2. Using it for doors or countertops as a sheet material the 5/8 can "stand on its own" where as the 22"x22" table top I made out of 1/2" had to have 3/4" fir rails on the sides for support. For my wall framing around and inside the window cavities I was able to butt (edge to edge) join the 5/8 to other pieces of 5/8. I couldn't have done it with 1/2. While there is space saving with the 1/2 over the 5/8, in some cases the reverse is true. Consider drawers. I didn't do a dado cut and slip in the bottom panel for my kitchen drawers. I figured this loses the drawer depth below the dado cut. Instead, I cut a 1/4" rabbit slice from the bottom of each side rail and glued and screwed the 1/4" plywood bottom for installation. (I know some people use 1/8" ply or pressboard material for the drawer bottom but I don't like it when they flex.) I couldn't imagine cutting 1/4" out of the 1/2 and joining the same way.
Benefits of 1/2"BB over 5/8"BB:
The 1/2 is significantly lighter. If you're concerned about your build weight, sheets of 1/2 will save many pounds (20% of the plywood mass) in your van payload. Being lighter, the 1/2 sheets are also easier to lift, maneuver, and work with overall. The 1/2 is plenty strong for cabinets and probably drawers too. The 1/2 is also less expensive. By the time you go from the front to back of your van, the extra 1/8" gained by using 1/2 vs. 5/8 adds up. An inch or two doesn't sound like much but in a compact van, it can mean the difference between having a bed that works for you... or not!
I've been using the Kreg pocket screw system (and now also expanded to a few other tools they produce) for several years now. I really like working with the system for both initial construction as well as "rebuilding" when needed. So my comments about what thickness of plywood to use for making cabinets is based on using the pocket screws for joinery. I've used 1x2, 1x4, 2x4, and 2x6 materials, 3/4" fir plywood, and true 1" boards to build many different things in the past. For this van build I've had the opportunity to add in both 5/8" and 1/2" Baltic birch for cabinet carcasses, doors, drawers, floor and wall framing, etc. The consistency and quality of Baltic birch is superior to the fir plywood that we get in North America. There's often voids or filler material in the fir plywood we get in our local stores. Because BB has so many plies for it's thickness, it is much stronger and stiffer by comparison. I haven't done any testing but the rigidity and strength of the BB makes the 5/8"BB feel like 3/4" fir plywood. When building a van using thinner material for the same strength for your build is always a good thing.
Benefits of 5/8"BB over 1/2"BB:
The 5/8 is much more forgiving in terms of tolerances. If you're not an experienced professional cabinet maker, the extra thickness of the 5/8 will allow more room for error when using the pocket screws. I'm pretty finicky and detailed when it comes to my finishing work, I work pretty accurately and feel I have pretty good skills with tools and my hands. That said, I still found times when joining the 1/2 material that there were bulges in some joins where the pressure of the screw passing through the pocket pushed the outside ply layers a bit. Maybe my alignment on those screws wasn't perfect? I don't think I ever had that happen with the 5/8. The 5/8 is also more rigid and dimensionally stable than the 1/2. Using it for doors or countertops as a sheet material the 5/8 can "stand on its own" where as the 22"x22" table top I made out of 1/2" had to have 3/4" fir rails on the sides for support. For my wall framing around and inside the window cavities I was able to butt (edge to edge) join the 5/8 to other pieces of 5/8. I couldn't have done it with 1/2. While there is space saving with the 1/2 over the 5/8, in some cases the reverse is true. Consider drawers. I didn't do a dado cut and slip in the bottom panel for my kitchen drawers. I figured this loses the drawer depth below the dado cut. Instead, I cut a 1/4" rabbit slice from the bottom of each side rail and glued and screwed the 1/4" plywood bottom for installation. (I know some people use 1/8" ply or pressboard material for the drawer bottom but I don't like it when they flex.) I couldn't imagine cutting 1/4" out of the 1/2 and joining the same way.
Benefits of 1/2"BB over 5/8"BB:
The 1/2 is significantly lighter. If you're concerned about your build weight, sheets of 1/2 will save many pounds (20% of the plywood mass) in your van payload. Being lighter, the 1/2 sheets are also easier to lift, maneuver, and work with overall. The 1/2 is plenty strong for cabinets and probably drawers too. The 1/2 is also less expensive. By the time you go from the front to back of your van, the extra 1/8" gained by using 1/2 vs. 5/8 adds up. An inch or two doesn't sound like much but in a compact van, it can mean the difference between having a bed that works for you... or not!
Which 1/4" material to use: Baltic birch or Marine Fir?
Nowadays, neither of these materials are inexpensive. I'm using them for things like: finish paneling (cut into 5" wide strips, bevel the edges), ceiling backer material (to attach the tongue and groove to), and layered with other plywood to make thicker material (1/4" + 5/8" to make the floor in the bed/dining area or with 3/8" to make my bathroom sliding door.)
When building the ceiling, I did not use furring strips attached the the ceiling beams of the vans. I figured if I was going to need surfaces to attach the tongue and groove pine to, I might as well skip the strips and attach the plywood panels directly to the beams. This would save me 1/4" in height loss. Interestingly I was at first thinking that I would want the entire ceiling covered in plywood and then attach the T&G. However, because I ended up attaching sheets between beams, that meant there were going to be spaces between beams that would NOT have any plywood backing. I went back and forth on how to proceed and decided to have no backing in some spots. This actually worked out really well; the reason? When I was trying to attach the T&G pine, it was really helpful to have gaps in the plywood backing so that I could slip small C-clamps in and use them to pull the T&G slats to the backer boards. When I had the plank lined up properly with the adjacent plank, I used a piece of wood and a hammer to gently tap the plank over to lock the tongue into the groove. Trying to line up the tongue and groove, bend it, and secure it all at the same time was impossible in many areas because the roof is so curved (and in two directions to boot!) The marine fir bent very nicely to the van roof. My guess is the baltic birch would also bend fairly nicely too. The baltic birch is certainly more solid if you have something substantial to screw into it. With more plus, the pull out strength is higher.
On the van floor I used BB because it was much flatter - this made for easier gluing to the sub floor panels I had glued between the floor ribs. I also wanted the higher pull out strength because various components were getting screwed into the floor. While I wanted strength from screwing into the floor boards, most of the structural strength comes from the 2x4 and 2x6 bracing that is bolted to the D-ring holes on the van sides.
In the bathroom I did use marine fir as the final layer that the vinyl and FRP was being glued to in areas where things might get wet on occasion. I'm not sure if this was necessary though because I was told by the supplier that both types of plywood use water proof glue in the laminating process.
Nowadays, neither of these materials are inexpensive. I'm using them for things like: finish paneling (cut into 5" wide strips, bevel the edges), ceiling backer material (to attach the tongue and groove to), and layered with other plywood to make thicker material (1/4" + 5/8" to make the floor in the bed/dining area or with 3/8" to make my bathroom sliding door.)
When building the ceiling, I did not use furring strips attached the the ceiling beams of the vans. I figured if I was going to need surfaces to attach the tongue and groove pine to, I might as well skip the strips and attach the plywood panels directly to the beams. This would save me 1/4" in height loss. Interestingly I was at first thinking that I would want the entire ceiling covered in plywood and then attach the T&G. However, because I ended up attaching sheets between beams, that meant there were going to be spaces between beams that would NOT have any plywood backing. I went back and forth on how to proceed and decided to have no backing in some spots. This actually worked out really well; the reason? When I was trying to attach the T&G pine, it was really helpful to have gaps in the plywood backing so that I could slip small C-clamps in and use them to pull the T&G slats to the backer boards. When I had the plank lined up properly with the adjacent plank, I used a piece of wood and a hammer to gently tap the plank over to lock the tongue into the groove. Trying to line up the tongue and groove, bend it, and secure it all at the same time was impossible in many areas because the roof is so curved (and in two directions to boot!) The marine fir bent very nicely to the van roof. My guess is the baltic birch would also bend fairly nicely too. The baltic birch is certainly more solid if you have something substantial to screw into it. With more plus, the pull out strength is higher.
On the van floor I used BB because it was much flatter - this made for easier gluing to the sub floor panels I had glued between the floor ribs. I also wanted the higher pull out strength because various components were getting screwed into the floor. While I wanted strength from screwing into the floor boards, most of the structural strength comes from the 2x4 and 2x6 bracing that is bolted to the D-ring holes on the van sides.
In the bathroom I did use marine fir as the final layer that the vinyl and FRP was being glued to in areas where things might get wet on occasion. I'm not sure if this was necessary though because I was told by the supplier that both types of plywood use water proof glue in the laminating process.
