Fitting rooflights can be complicated on panel vans, doesn't matter what base vehicle you use they all have ribs and ridges on the roof making the sealing of the rooflight difficult
We have to be honest we actually cut the holes for the rooflights right as the beginning of the build and have lost the photos so cannot show you these. However we will still talk you through how we went about it.
Step 1 is to measure, and cut out the rooflights. Once your design is final you can mark the rooflights onto the roof, in this case we are using
Fiamma Vent 28 in the shower room
Mini Heki Rooflight
Midi Heki Rooflight
For the Fiamma vent we need a 280mm x 280mm cut out, the Min Heki we need a 400mm x 400mm cut out and for the Midi Heki we need a 700mm x 500mm cut out
As we have already made sub frames in "Stage 3: Roof Lining" we already have the timber lining for fitting the rooflight. So all we do not is drill the corners with a small 3/16" drill bit, we then use a larger drill bit to make the hole big enough to fit the jigsaw blade through. We then cut along the lines between the holes using a Jigsaw (Fitted with steel cutting blades)
So for example now there is a 400mm x 400mm hole for the Mini Heki rooflight, which has a 25mm timber frame on the inside.
The biggest problem we have is the ribs on the roof, this is the same on all panel vans, they all have different shape ribs on their roofs. How we ensure that we get is seal is to build up the valley between the groves using PVC window boarding. This is almost perfect thickness to make the valleys between the ribs the same height the peak of the ribs.
Once we have all these cut to shape and size, making them wide enough for the lip of the rooflight to sit on we bond them into place using Wurth Bond & Seal and use clamps to hold them overnight while the adhesive goes off.
Once set we have as flat a surface as possible to bond the rooflights onto, we apply mastic sealing tape to the lip on the Heki rooflight, then drop this into position form the top, pressing down firmly to make sure we get connection between the mastic and the roof. With the Mini Heki there is a fixing plate on the inside, so we put this in place and screw together the inner and outer from the inside. Always trying to make sure we tighten each screw evenly to get even pressure. This will force the mastic to make a seal with the roof and give us a seal.
Now finally to make triple sure we do not get a leak we point up and fill any of the very small gaps with some more Wurth Bond & Seal, then apply a bead to the edges of the Heki lip and our PVC packing. We also apply a bead to the edge of the PVC packing lip and the roof. Then using a white spirit dipped finger we point up to make it look as nice as possible. However with the rooflight not being seen the seal is more important than the look.
All that is left to do now is clip the decorative blind and flyscreen to the fixing plate using the clips provided with the Heki rooflight. Please note we will be trimming round the sub frame when it comes to fitting furniture later in the build.