How to clean a convertible canvass roof.

Hi all,

Though I'd share my experience as I did hours and hours of research to see how to clean a convertible canvass Audi roof on my A4 cabriolet. My problem is, I had mold so bad..nothing, and I mean nothing seemed to have removed the mold.

I promise you, all roof cleaners are utter bo**ocks! They simply did not work as there is no proven 'science' to clean a roof as so many companies claim.

What I did which worked to PERFECTION is;

1. Rinse the car and roof with a pressure washer.
2. Add 'Miltons' baby sterilizer fluid to a bucket. Use the instructions of what ratios etc. You can be generous with the sterilizing fluid as it wont bleach or change your roof colour.
3. Take a bristle brush, but the soft one used for household washing and scrub the solution into the roof. Its a lot of elbow grease involved to cover the whole roof but you should see the mildew being penetrated.
4. Leave to soak for like 30mins or so.
5. Pressure washer time. Get a ladder, and take the pressure washer, spraying the roof section by section keeping the nozzle of the pressure washer VERY close to the roof. Im talking just 5-10cm away. By doing this you will literally be going back and forth 30 odd times but you will see how effective this is as you will see 'clean' lines as you do it.
6. After the whole roof is done, wash the car and hood with a microfiber cloth. Then Pat dry the roof with a cloth that doesn't leave material on it.

The Results;

My Roof looked BRAND NEW! Oh and...my roof is navy blue so dont worry about colour fade or anything similar.

Other things to point out..

A - Your roof wont leak if its closed properly. Mine didn't even in the nooks and crannies.
B - You must use a pressure washer and...very close to the roof it it was as stubborn as mine!

Hope this helps..

gary_tfsi_quattro said:

Not trying to be negative, but I really feel I must point out that using a pressure washer on any fabric hood and especially, one that may potentially be an older fabric top is not a good idea.

I'm not doubting the efficacy of the process used, its more the effect on the servicable life of the tops.

The hooding fabric is manufactured as a lamination (in the case of A4 Cabrio; the Haartz A5 series ) of three layers; an outer acrylic weave layer, the mid elastomer layer and the inner woven polyester layer. Using a pressure washers, especially at such close quarters, will potentially cause delamination and porosity in the waterproof elastomer membrane there-in. It has never been designed to withstand 100+ bar water jets spraying at it.

On the point of the Milton fluid, I've heard people have had good results, but as yet have no direct experience with Milton to pass any comment. I will take the opportunity in the near future, to see how things go using it.

Using a hose with clean running water and a soft brush to aggitate and work the chosen cleaner product into the fabric is ok, a pressure washer could really cause more harm than good.

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Hello Gary,

Thank you for your input and obviously knowledge on the material used in an actual Audi canvass Roof.

My point is, I have tried everything under the sun and absolutely zero had an even mild positive result. They simply did not work and the mildew/mold on the hood mixed with dirt did not shift at all. Just to be clear, I spent hours trying different methods on different days to no avail.

As a result of my method, mixed with others I took on board, I was able to shift EVERY single spot. My roof looks brand new! I concede, I have not treated it with a repellent or something similar but will do when I do some research as to recommended and tested ones.

I welcome anyone to try the method I used and report the results.

Fox5150 said:

Worth keeping an eye on the Auto Finesse product line as they have something coming out specifically for this. Have a look here for more info: http://www.detailingworld.com/forum/showthread.php?t=356499

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Thanks for the link! Just to clarify, the hood pictured in the link provided was in a state a WORLD better than mine when I first tackled it. Im really focusing on accumulated mold and dirt from perhaps a mis treated hood as mine was obviously neglected.