Caravans dating from the nineties are often a little murky inside, thanks to flickery fluorescent lights, rather small windows and opaque roof vents.
Penny’s windows are getting a drop of Autoglym on a soft cloth, but cleaning a caravan can only do so much – both the lighting and roof vent are both improvable.
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Why the caravan roof vent needed to be replaced
I’d been looking into sourcing spare parts for my caravan, and a chance find on Facebook Marketplace prompted the roof vent upgrade.
Penny was reasonably well equipped in 1998, and one of several nice items was a kitchen extractor roof vent. But when you’re buying a used caravan, the chances are the spec will have seen better days – and that was definitely the case with Penny. It was filthy, having extracted a lot over the years.
Cleaning is not a big issue, but more problematic was the state of the support legs. Two were broken, so the vent could be opened, but it just flopped about. There was really no point cleaning a broken vent – instead, the caravan roof vent would need to be replaced.
The other issue was the lack of daylight in the middle of the van. The opaque extractor vent didn’t let in much light, so we decided to look at our options. The vent opening was the standard 400 x 400mm, so we had a good choice of solutions. We could have bought another extractor vent, but given that we don’t do a great amount of cooking in the van, and they are very noisy, we decided this was not for us. Instead, we decided to look for a standard opening roof vent without an extractor, but with a clear cover to throw a little more daylight around, something which can make a real difference in even the best used caravans.
Top of the line for clear, opening roof vents is the Seitz Mini-Heki. The only obstacle was the price. A Mini-Heki is around £150, which is a lot when we had only bought Penny for £1200. That was when Facebook Marketplace came up trumps. A few miles away, someone listed a Mini-Heki rooflight for sale, in good condition and complete with all the screws and fixings. It had been removed from a motorhome to make room for an extractor fan!
Finding the replacement roof vent
Our secondhand Heki looked great (see my tips for finding spare parts for an older caravan if you’re van is also in need of some repairs). The previous owner had kept all 12 fixing screws neatly in a bag, cable-tied to the frame. The important fixing frame that goes inside the van was present and intact, and the integrated blind worked as it should. The vent was pristine, crack-free and operating perfectly.
The previous owner did a pretty thorough job of cleaning the old sealant. That said, the bedding mastics used in vans are pretty resistant to removal, so before starting work, it still took an hour or so of detailed cleaning to remove every trace of the old stuff – vital to ensure a leak-free install.
We used white spirit to soften the sealant, and a small metal scraper to shave the remnants off the mounting plate. For the tight areas, we used lint-free cloth and electrical screwdrivers wrapped in paper towel. Then the whole surface was wiped in acetone to get rid of the oily residue from the white spirit.
With that preparation work completed, we could move to Penny’s roof. Removing the old extractor vent was simple.
Taking out the vent
Most vents of this type fit the same way, with an outside part, which sits on the roof, attached with some sort of sealant.
Below the roof is a frame that screws to the outer, through the roof aperture.
The screws are tightened inside the caravan, pulling the outside component evenly into contact with the roof surface. The sealant is uniformly compressed and the result should be a neat, watertight and strong bond between the vent and the caravan roof.
Despite the damage to the old vent, we found it was firmly stuck in place. We removed all the securing screws and the inner restraining component, leaving just the roof-mounted part, attached with the sealant. This put up quite a fight.
We carefully pushed a scraper between Penny’s roof skin and the vent to cut the sealant, and once we’d done that all the way around, we lifted the vent clear and consigned it to the skip.
This left us with a sticky mess of old sealant stuck to the roof, which would need to be pristinely clean before we could even begin to think about fitting our new vent.
Up on the roof
Working off a ladder on a warm day, removal of the sticky muck was taken on in overlapping shifts between my father-in-law, Sam, and me. It was slow work, too, using a scraper, more white spirit (and a fair old sprinkling of swear words).
Great care is needed in this kind of work to avoid damaging the delicate aluminium roof skin. Around 90 minutes of fiddly cleaning got the sealant off and left us at last with
a smooth surface, ready for the final preparation.
We gave the wider area around the rooflight a good clean with an aggressive mix of Fenwicks Caravan Cleaner, one of the best caravan cleaners, to ensure there was no algae or other muck to contaminate our new seal.
With the cleaning done (and make sure you know how to clean a caravan roof if you have the job on your to do list), the final task was a thorough wipe with more acetone to ensure a clean, dry surface for our new bedding mastic to bite into.
Helpfully, the Mini-Heki has a channel moulded into the base. This is ideal for putting a good thick bead of bedding sealant into, before fitting it to the caravan roof, and that is exactly what we did.
We got a tube of Hodgson’s Seamseal CV for the job. This was available on the shelf at our local caravan shop, Reading Caravans & Motorhomes, and at a fiver, I didn’t think it was a bad price, either.
Applying the sealant
We cut the end off the nozzle to provide a good thick bead of around 8mm. We had the Mini-Heki upside down on the bench, resting on a soft surface to avoid scratches. I started in the middle of the back edge, putting a generous, continuous bead of sealant all around.
I asked Sam to hold the vent still while I worked, and also to carefully turn it when I reached the corners to ensure a nice even bead all the way around.
It is essential that there are no gaps in the bead, and that it is thick enough to protrude above the sides of the channel. This will ensure that the bead contacts the roof properly and is compressed when attaching the base of the plate inside.
With the sealant applied, we were out of excuses. It was time to attach it to the van. Sam was sent up the ladder and once he was comfortably at the top, I passed him the Mini-Heki, careful to ensure it was the right way around so he could drop it into place. It is a pretty good fit in the roof aperture, so once it was centred over the whole, it popped into place and I got to work inside the van.
Installing the long stainless steel screws is a good test for the arm muscles! I offered the inner frame up to the main Mini-Heki assembly, which was now poking into the interior.
The 12 screw holes line up neatly with the Heki frame, and once you have the first couple of screws started, you don’t spend your time trying to hold the frame, hold the screws and turn the screws all at once. If you have a friend to help, this is the time to draft them in!
As a word of warning, the inner frame can go in two ways – the screws line up both ways. But the sun blind and flyscreen only fit one way. Ensure you get the inner frame the right way around, or you will end up undoing all 12 screws, removing the inner, rotating it and reapplying all 12 screws. Ask me how I know…
We did up all the screws until we felt some resistance, and this was the point at which the bottom frame pulls the main unit down to compress the sealant and ensure a neat, watertight fit.
Placing the new vent
We tightened the screws in a diametrically opposed pattern to ensure that the Mini-Heki wasn’t twisted as it was being snugged into position.
This took about 20 minutes, but be really careful not to overtighten the screws. They are only pulling into plastic, and stripping the thread would be a headache. This is why we left
the electric screwdriver in the caravan tool kit, opting for gentle nipping up with a regular screwdriver. We tightened all of the screws until they were firmly hand tight.
The final task is pushing the integrated blind into place. The blind is attached to the inner frame using barbed clips and needs lining up, then a firm tap with the flat of your hand all round to push it into place. That finished the inside work.
Outside, we looked at the roof, smoothed off any sealant that had oozed out, and that was it: job done.
One small task remains. The switch for the old extractor fan fouled the edge of the rooflight. We’ll need to isolate the cabling and tidy up the ceiling when we tackle those lighting issues.
If you’re giving your van a spring clean before the start of the new season, make sure you have the best caravan vacuum cleaner to help you keep your tourer in tip-top condition.
Future Publishing Limited, the publisher of Practical Caravan, provides the information in this article in good faith and makes no representation as to its completeness or accuracy. Individuals carrying out the instructions do so at their own risk and must exercise their independent judgement in determining the appropriateness of the advice to their circumstances and skill level. Individuals should take appropriate safety precautions and be aware of the risk of electrocution when dealing with electrical products. To the fullest extent permitted by law, neither Future nor its employees or agents shall have any liability in connection with the use of this information. You should check that any van warranty will not be affected before proceeding with DIY projects.
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