A little while ago I promised MBH that she could have a fan-assisted vent in the sleeping area of our 670 Tribby (a Fiat Ducato van conversion) because of the heat we had experienced on our travels in Europe. This wouldn’t be an issue if touring in the UK as the temperature seldom rises above tepid but in France we had experienced internal temperatures of up to 46C.
We had a 2004 Tribby a few years ago and I took the decision to replace both roof vents with fan-assisted ones as the transparent cover on each was cracking and discoloured. The result was everything I could have hoped for.
I went back to the mechanic who had fitted the roof vents to the previous vehicle and asked him to quote me a price. He hummed and tutted and then told me that it was something he wasn’t sure he could do (?) because he didn’t know where the power would come from (the previous Tribby had a light fitting in the roof just a few inches away). He wasn’t sure what sealant would be needed for the job. He suggested going back to the manufacturer for advice.
I wasn’t hugely impressed with this response and wondered if it were possible for me to do it myself. I’m quite competent at DIY and thought I might be able to take a 12 volt supply from the myriad of light fittings above and around the cupboards lining each side of the rear compartment. Of course I needed a constant supply, not one that worked only when the light was on!
I allocated two days for the job which was far too long as, apart from the wiring, the whole thing was done and dusted in a couple of hours – and much simpler than I feared.
First, the new fan and roof vent. These are a standard fitting (sic) and the new one should fit smoothly in the hole left by the old one. I went for a similar model to the one we had before, from Fiamma, the Turbo Vent Premium which has the fan power to lift the Tribby from the ground like a rather flashy hovercraft as well as an automatic and amusingly named ‘Polar Control’ system which uses a variable fan speed to reduce the internal temperature by between 1 and 5 degrees.
Its simple touch controls make it easy to bring air in or push air out of the space and it still retains the lifting cover in either smoked clear plastic or white. (Not MBH in the picture).
The electrical bit. I tried removing the cupboards to get to a power supply but, after spending hours locating and removing a mass of screws including half a dozen in the bathroom I began to realise that the only way the cupboards were coming down was with strategically placed plastic explosive. I searched further and realised two things: first, that the manufacturer had provided a power supply to the TV aerial amplifier close by and, second, that there was a double plywood skin in the roof space through which a power cable could be carefully threaded to reach the power supply to the aerial. Result!
This isn’t the actual wiring – there are two wires for the motor and two for the power input.
The installation. This was the bit that gave me concern because one false move and I could either damage the roof or the fan or allow water to leak into the roof space or drip onto our fixed and very comfortable bed. The installation manual recommends a sealant called SIKALASTOMER-710 or THEROSTAT II but I contacted AutoTrail and ended up with a non-setting butyl elastomer as they suggested. I bought three tubes but ended up using half that so two tubes would be sufficient. Removing the old vent was relatively simple.
I had watched two videos from Practical Motorhome’s Diamond Dave which I had recorded on TV but which are now available on YouTube here https://youtu.be/laFYwXf7DBs and here https://youtu.be/z6pjzE1rz-M and I followed his advice to the letter.
The old vent came off in less than five minutes (with a power screwdriver) and it took ten minutes to strip away all the old sealant and rub down the surface to prepare for the new.
NB. Trigano have cleverly set up the roof vents by setting them in two stages to take into account the ridged roof. I only needed to remove the sealant from the upper level, leaving the black/grey platform sealed to the roof and providing a flat surface for the new vent to fit.
Tip. Not all the roof is safe to put your weight on. First you need a high step ladder to reach the roof held by your willing assistant. The area at the back of the roof vent, essentially the last metre of roof, is nothing more than a thin metal skin above an empty roof space of around 2 inches. The sides of the roof and the central portion is supported by transverse metal struts which will support your weight. I now have a couple of small dints in the roof at the back where my knees learned this lesson.
I cleaned off all the old sealant with a thin bladed decorating wallpaper scraper and then rubbed down with fine sandpaper to key the surface ready for the new sealant.
NB. At this point it’s worth noting that you have a collection of 20 screws from the old roof vent which need to be reused but which are all covered in sealant and a good few not particularly straight.
I found three screws which were bent enough to need straightening carefully. I find an easy way of stripping off all this used sealant was to insert the sharp end of each screw into the chuck of a drill and then run the drill pushing the screw onto a dense wire brush. This cleans them up quickly and neatly.
The instructions told me to apply sealant to the underside of the new vent and this is what I did. The vent has four tracks on its underside and these need to be filled with sealant in a continuous stream so an assistant is useful here to turn the vent body (on a cloth to avoid scratching the plastic cover) as you apply sealant.
In the next phase an assistant was vital because I needed to locate the new vent in the roof hole exactly without being able to see what I was doing from above.
First, I marked a few of the screw holes with a pen so that I would be able to see where they are when I lowered the vent into place.
Next I got my assistant to stand below the hole and guide the vent into place while I gingerly lowered it from above. It needs to be lowered with the hinges towards the front of the van or the wind will get underneath it and rip it off while you are driving.
Once the vent has been lowered into place then I fitted the corner screws loosely to hold it in place. Next I worked around the vent with the remaining 16 screws tightening each gently as the mastic began to ooze out.
Tip. Don’t press down on the vent cover but let it sink into place as the screws tighten.
I left the vent for half an hour (to have a cup of tea) then I went back and tightened each screw again in turn. I did this once more until I was satisfied that the vent was evenly seated and secure.
All that remained to do was for me to connect the inside panel, attach the power cable (with the battery disconnected) and locate the control knob with the cover raising mechanism. And that’s where I saw the problem.
When Trigano converted the Fiat Ducato van they inserted a sizeable roof space between the outer shell and the inner finish. This roof space is around 35mm in depth and is double skinned. The obvious intention is to provide for differential expansion in hot weather. The problem is that the Turbo Fiamma roof vent assumes a maximum depth of around 30mm meaning that the winding knob doesn’t reach the winding rod for the vent cover.
After cursing and swearing enough to traumatise the neighbour’s cat I repaired to the living room to let my fingers do the walking through the world wide web. I found out after some searching that Fiamma have spotted this problem and do offer an extension kit to solve this problem. Unfortunately they do not seem to have any stock in the UK and eventually I persuaded a dealer to persuade Fiammastore to import one for me at a cost of around £13. I noted that the kit has a different part number than shown in the Fiamma catalogue.
Tip. It might be a good idea to push some insulation into this gap if you are planning to further winterise the van. Possibly foam chippings or even bubble wrap might work while you have the vent off. In any event you might consider ordering the extension kit at the same time as you order the vent.
Suffice to say, it took only a few minutes to fit the extension kit, offer up the lower assembly which includes the electronic board on a rather flimsy setting and then re-attach the blind so our nights can be dark as well as cool.
I gained immense satisfaction from doing this job as well as family cred for sorting out the issues.