I have heard all sorts of theories why the Carryall and the Panel van (but not the Panel Radio) had the fibre roof insert which all owners know and love. Perhaps the most colourful was the theory (from an English owner) that the things were so easy to turn over on rough ground that you needed to be able to boot out the roof panel and walk out when the truck was on it's side…..and I'm not saying he was wrong.
The truth seems somewhat more mundane. These vehicles were developed from '20s and '30s standard cars, which all had this sort of roof because it was cheap, and the use of the insert panel could be traced back to the horse-drawn vans they superceded. The Carryall body is not the best example of this, the early pickup body sides are just metal versions of the wooden wagon sides they replaced.
If you have a Carryall or van, do you really need to replace the roof with the original type? Most have been replaced over the years with sheets of tin, aluminium, or steel welded, riveted, screwed, or leaded into place. To a large extent, your need for a new roof will be determined by the quality of the job the last chap did. I have seen one steel roof panel that was leaded into the original surround channel, and it was such a nice job that replacing it would have been a sin of the first order.
Assuming you are convinced that the roof does need to be replaced, you will need the following material:
A complete length of the special roof seal (Vintage Power Wagons again, or Jaap Rietveld if you are in Europe)
A standard sheet of 1/8" hardboard, 8 foot by 4 foot (basically bigger than the hole in the roof)
Fibre board or wood for the cross bearers (approx. 4" x 5/8", four lengths of 4 feet)
A roll of car sunroof grade external vinyl (big enough to cover the hole by a couple of inches all round) plus a small can of adhesive. Buy the colour they can't sell - you'll be painting it anyway.
Rubber (house) roof sealing paint, with appropriate primer.
Usual tools, paint, screws, etc, etc.
In addition you will also need the appropriate tools to repair the steelwork surrounding the roof insert, including welding, leading, whatever.
A special word about safety here. Most of the work can be done standing inside the vehicle on the floor, but when it comes to the final installation you will have to work externally at height. Be prepared to use scaffolding or whatever to give you a solid footing in addition to the normal dust mask, gloves, etc, etc.
When you have removed the previous roof, you will undoubtedly discover some trouble. Be prepared to weld up the two hundred screw or rivet holes that the last chap left. This is the time to clean and reinforce those four cross members, replace the little metal tabs that hold the roof insert down, and clean out and paint the rubber insert groove. Don't rush the preparation - you need to be left with a respectable roof which has a decent groove all the way round - not too far out of flat or with a groove width variation that will make it impossible to install the seal or keep it in there. You can use some filler to get the surface profile right, but remember you will be hammering in the rubber insert so no point in expecting ordinary filler to withstand that. Do remember to replace the wire for the roof light first, because you won't be able to get to it later. While you are at this stage have a hard look at the metal filler strip that runs across the cab roof. This is the time to replace or repair it. In extreme cases, if it is completely gone, you might want to just remove the remains and lead the joint instead - you will never have a better working position than you do while the roof insert is out.
Some owners make the mistake of leaving the roof flat, and just putting 1/2" wooden bearers across the top of the metal ones. Since the seal edge sticks up 1/8" or so, the whole thing fills up with water and then life gets unpleasant. To avoid this, I cut cross-bearers out of MDF (Medium Density Fibreboard) to fit each individual cross bearer for length. Using MDF means I can leave it 5/8" thick in the centre but sand it down (dust mask needed) to about 3/8" where it meets the roof edge. This ¼" curve ensures that water rolls off the turtleback and you stay dry. Attach the MDF to the cross bearers with ordinary nuts and bolts, but recess the MDF so that the nuts are countersunk. Last chance for that roof light wire !
Drop the hardboard onto the roof, polished side up, so it is overlaps all round, then climb under it and mark the edge all round with a pencil where you can get to it. Take it off again, join up the pencil marks, measure the extra you need to get to the little metal clips all round, and just cut it to shape. Drop it back on and clip it down with the little sheet metal clips that you did remember to repair before you started ? - feel free to make bitter remarks to the deity of your choice when every second one breaks as you bend it. When the fit is satisfactory and it is clamped down you can use a proprietary panel sealer to fill the joint between the board edge and the inside of the metal groove edge. It is particularly important that no sharp edges are left to cut or wear upwards through the roof cover. On one particularly difficult installation, I had to cheat and use a few very small screws and rivets to hold down a leading edge that the metal tabs couldn't cope with. When the board is sealed in place, you can paint the whole thing if you want with any waterproof paint.
This takes a little time to do - don't rush it as time spent here will show on the final job. Run some adhesive down one edge of the roof board, and lay the vinyl in place so it overlaps all the way round the groove edge. Go and have a cup of tea / coffee / beer while the glue dries.
Throw the cover off over the side revealing the rest of the roof board. Spread a decent amount of the adhesive over the exposed area of board, throw the cover back across, and let it dry for a few minutes. After ten minutes or so (depends how long it takes for your adhesive to get really interested ) stretch the vinyl away from the first area you glued, and peg it into the roof channel with something hard enough to retain it but not so hard it will risk cutting the edge of the vinyl. Now go away and do something else, anything else, but check after an hour or so and re-tension the vinyl. Get rid of bubbles, get the tension even, make sure the vinyl hasn't crawled or come away from the securing pegs. If you have the chance, get to this stage at the end of your first day and leave the adhesive overnight to set once you have checked it a couple of times.
On the morning of day two, pull the pegs out and check that the vinyl is bonded to the board pretty much all over. If it looks horrible, ease it off and do it again - vinyl will take it if you have used reasonable adhesive and not epoxy. Once you are happy with it, cut the vinyl all round so it will reach the bottom of the groove. This is not what the manual calls for - it tells you to leave material that will reach across the groove and trim it outside the groove after putting in the sealing strip. Vinyl is about twice as thick as the canvas used originally though.
This is where the fun starts and tempers rise. Don't be surprised if you have been sold a sealing strip that appears too short for the length of the groove. Since the strip is stretched into position, you can make the strip do the job if it is 18" short if you have to. There are really two methods of placing the strip, and either will work.
Either is a valid method of doing the job, but I prefer the first way, so:
Check the length of the strip against the groove, cut the strip 6" shorter than the groove with a really clean end cut, then superglue the ends together ( after checking you don't have a knot in it) Find a bit of heavy gauge copper wire and make a 'U' staple. Drill vertically down through the strip about 1" each side of the superglued joint, push the wire staple through, bend the ends over and lock them together flat so they clear the bottom of the groove when fitted. Place the joint at the rear centreline of the roof and stretch it into place in the groove working in each direction away from the centreline. Use a 2lb hammer to really pound it into place but keep some tension on it all the time. Once it is started just work round the vehicle until you are about two thirds of the way round, then position the middle of the remaining section and work back to even up any slack you may be left with. Don't be afraid to just pull it out and shorten it if it is obvious you still have too much seal left. If you really get stuck, you can work it in all the way round and then just re-make the stapled joint.
Once you have the seal in place, mask the body and the vinyl about 1.5" either side of the seal all the way round. Paint with the rubber roof repair primer, and then the rubber roof paint after the right primer curing time. As soon as the rubber paint is on, pull the masking tape off as you don't want it trapped. Leave for a day or two to cure fully, then overpaint the whole roof with the vehicle finish colour. The rubber paint effectively seals the whole assembly and removes the need to work sealer under the strip edge.
If it's done properly, you should never have to worry about that leaking roof again.
Copyright Gordon McMillan 2000
See anything wrong with the above? Know anything to the contrary that should be added or corrected ? Email me and I'll get it done.