Roof racks - good, bad, and horror stories

[cheapliving]

Measure and double check, and if too close to something you want to avoid, drill a pilot hole from the INSIDE first.

Using solar on top as an example, when people say to measure, do they mean to measure from one end of the van's interior to a spot where there is nothing attached to the interior ceiling, and then apply that same measurement to the exterior and drill your holes there? 
I look at any vehicle, stripped down to the core, as a series of layers. The exterior body that is visible is a layer of sheet metal. The interior wall is not normally that same layer of metal. It's some other material that the manufacturer decided would be used for the interior walls. It could be plastic, wood, a different type of metal, or whatever, just as a house has bricks on the outside, insulation (hopefully), and sheetrock or stucco as the final interior layer. Then there's space in between and who knows what else, like wiring. Unless a person watched the construction of their van/RV at the factory and took pictures, they don't really know what all is where. Let's say I go to install hardwood flooring in the floor, or insulation followed by wood paneling in the walls, or solar on top...if I don't know how much space there is between the surface I'm drilling and the next layer of whatever comes next, I have no idea if that drill bit is immediately going to come into contact with the second layer of material, whatever it is, immediately upon cutting through the first layer I can see.

 

[VanTalk00]

 Let's say I go to install hardwood flooring in the floor, or insulation followed by wood paneling in the walls, or solar on top...if I don't know how much space there is between the surface I'm drilling and the next layer of whatever comes next, I have no idea if that drill bit is immediately going to come into contact with the second layer of material, whatever it is, immediately upon cutting through the first layer I can see.

I have crawled underneath my van over a hundred times.  The floor is stamped with a pattern of bumps and valleys that can also be identified from underneath.  It is a real challenge finding a spot under the floor that is unimpeded by equipment to readily identify where holes can be cut or drilled that are also compatible with your design for the living space.  I will have a video about this process in the next week or so.  I cut two holes in the floor for ventilation for my electrical equipment and fridge.  The electrical hole had to be an oval to accommodate the gas tank fume collector.  I then created a silicone/corn starch gasket to attach a screen (for bugs) and a receptacle for a foam board plug.

To get an idea of  where everything is, I first bought the complete drawings for my vehicle from All Data DIY.  However, after inspecting the material in depth, I concluded the info was really no better than what you can get from Mopar or other part suppliers, so I got a refund.

The other thing I did was buy a fairly cheap endoscope that transmits to a smartphone to let you snake inside cavities to see what's there. See this amazon link.

The ceiling is quite a bit simpler.  You really need to identify where the supports for any kind of factory-supplied roof rack are located.  Whatever you do on the roof can be referenced from those bolt holes.  In my van, and I would guess, others, these roof rack supports originate from struts across the ceiling that are a different type of steel than the sheet metal roof, and much stronger, designed to convey the roof load to the sides of the van.

Basically, you need to look at the inside and outside of your van a thousand times to really understand where everything is and why. It's also tricky because your perspective is really skewed looking over and then underneath. Once you do understand, you feel much more confident drilling holes where you need to.

Best,

Jim

 

[highdesertranger]

just to clear things up the ribs on the roof are not a different type of steel. they are a little thicker and all the bends in them give them their strength. highdesertranger

 

[VanTalk00]

just to clear things up the ribs on the roof are not a different type of steel.  they are a little thicker and all the bends in them give them their strength.  highdesertranger

Well, that is one of the things I learned from AllData.com - that different parts of the Promaster City chassis are made of different types/grades of steel.  They're even color coded in their diagrams.

 

[Seminole Wind]

Using solar on top as an example, when people say to measure, do they mean to measure from one end of the van's interior to a spot where there is nothing attached to the interior ceiling, and then apply that same measurement to the exterior and drill your holes there? 
I look at any vehicle, stripped down to the core, as a series of layers. The exterior body that is visible is a layer of sheet metal. The interior wall is not normally that same layer of metal. It's some other material that the manufacturer decided would be used for the interior walls. It could be plastic, wood, a different type of metal, or whatever, just as a house has bricks on the outside, insulation (hopefully), and sheetrock or stucco as the final interior layer. Then there's space in between and who knows what else, like wiring. Unless a person watched the construction of their van/RV at the factory and took pictures, they don't really know what all is where. Let's say I go to install hardwood flooring in the floor, or insulation followed by wood paneling in the walls, or solar on top...if I don't know how much space there is between the surface I'm drilling and the next layer of whatever comes next, I have no idea if that drill bit is immediately going to come into contact with the second layer of material, whatever it is, immediately upon cutting through the first layer I can see.

experience, skill, practice, patience and luck is what it takes. of course you will bugger some stuff up as you develop a couple of those. when you mark a hole on the roof from the outside for example. take a look around. are there any distinguishing marks or other bolts to measure from, a vent or even just from the side or back. then it is still a bit of a guess on the inside as often what you measured from on the outside is not exactly the same on the inside. as for the different layers, with practice you can tell by feel whether you are drilling the roof metal or have gone trough that and now hitting wood or plastic. if possible remove the inside layers, then drill and secure your fasteners. then put the inside layers back up and you have a good looking job well done.

dont expect your first project to be perfect. be prepared to patch some mistakes. you will learn and get better. bet even years and many many builds down the road. you will still pucker up when you start cutting into someone else's rig...