Top Box Off - Roof Vent In

It was on my last trip that I decided I needed a roof vent in the van, it was still quite chilly so the doors were shut and as soon as I started cooking the smoke alarms would go off.

For a while I have been thinking that the top box was not really needed, it contained 2 chairs I never used, a hosepipe I never used and a pair of wellies which could be stored in the van. So the simple answer seeing as there was no more room on the roof was to take the roof box off and put the roof vent in it's place.

After some measuring I found there was enough room to fit a 40x40 vent on the square flat panel on the roof which would also fit centrally in the ceiling space available. The Fiamma 40x40 vent was the one I opted for.

First job after a lot of measuring was to cut the Veltim lining to size using a sharp Stanley knife, when I was sure this was the right size and square I cut the plywood lining to the same size using the multi-tool, I knew there was a cable running across to the rear light so had to be careful cutting.

Next job was to extend the cable so that it could be moved out of the way, just a two minute job. Then I had to make a framework to take up the space between the plywood ceiling and the van roof, this is needed to screw the vent into. This was screwed into place through the plywood.

Now I would have to wait for a sunny day for the rest of the work as it involved cutting a hole in the roof.

2 days later we had a sunny day so time to get on with the nail biting job of of cutting the hole in the roof.

I drilled 3mm pilot holes in each corner from the inside, just a little way in from the corner as the bit used from the outside would have to be big enough for the jig-saw blade to go through.

It is then a good idea to suspend an old towel or something similar under where you are going to cut the hole to catch all the filings that you will get when drilling and cutting the roof, these filings get everywhere if you don't they can be dangerous if any fall on the floor where people walk, and they also can cause rust if they land on metal parts.

Then on top to drill the bigger hole and checked inside to make sure they were right in the corner.

Back on top and a line was drawn between each of the holes, checking and measuring several times to make sure the hole would be the correct size and square.

Cut the hole without any problem and then made sure that all the filings were cleaned up.Then I painted the bare edge of the metal and also the wooden frame.

After testing the vent in the hole to make sure it fit correctly, the roof was thoroughly cleaned with Isopropanol, this is essential to get a good bond. Then a liberal amount of Sikaflex was applied to the surface of the vent that would come into contact with the roof, then it was just a matter of putting the vent in place.

The vent is then screwed to the roof with 20 screws, the screws do not come with the vent as different thicknesses of roof will need different lengths of screws. I used one and a half inch screws, which must be round head and not countersunk.

I screwed one screw in each side first then smoothed off the Sikaflex round the outside making sure there was a good seal. Then the rest of the screws were put in, I used a 3mm drill bit to make a pilot hole for each one. 

Then each screw head was covered in Sikaflex, this is important to make sure the job is fully weatherproof.

I also had to cover the 8 screw holes that had been made to secure the top box down, I had some thin plastic sheeting which I cut to size and stuck down with plenty of Sikaflex, again smoothing round the outside making sure that it was weatherproof.

The inside frame was then secured to the top part with 4 screws, I had to use 2" screws for this.

I also needed the extension kit for the winder that opens the vent, quite expensive but needed unfortunately, the cost is due to the fact that the extension parts are included for all the other Fiamma vents, I only needed one of the parts so there were 3 items that I did not need.

The photo on the left is the finished vent from the inside and is opened by turning the knob, the fly-screen is part of the vent and is permanently in place.

The photo on the right shows the vent with the cover in place, this cover does not come with the vent, it is an extra which cost £7.50 plus postage from Fiammastore.
The cover comes with 3 plastic channels, that fit 3 sides of the cover, there is also a roll of heavy duty double sided tape in the kit to stick the channels to the vent, the cover is then slid into the channels.