Preparing your convertible roof for summer — here's how
Summer is on its way and you want to drive with the roof down without a care. But after months of rain, cold and dirt, your convertible roof needs maintenance. A well-prepared roof looks better, repels water more effectively and lasts longer. In this article you'll find out exactly how to get your fabric or vinyl convertible roof ready for the summer season — at home, without any hassle.
Why your convertible roof needs maintenance now
During autumn and winter, your convertible roof is exposed to moisture, dirt, bird droppings and traffic pollution. That combination does more damage than you might think:
- Dirt penetrates the fibres and makes the fabric look grey or stained
- The water-repellent layer gradually wears off through rain and friction
- Stubborn stains become harder to remove the longer they are left
- An unprotected roof absorbs moisture more quickly, which can eventually damage the material
Spring is therefore the logical moment to clean and re-protect your convertible roof. That way you head into summer with a roof that looks fresh and is well protected against sun, heat and summer showers.
Which type of convertible roof do you have?
Before you start, it's important to know what material your roof is made of. Most convertible roofs fall into two categories:
- Fabric roof (textile) — Usually acrylic or polyester. Feels like fabric, has a slightly rough texture. This type is most common on brands such as BMW, Audi, Volkswagen and Mazda.
- Vinyl roof (plastic) — Smooth, glossy surface. Resembles firm plastic. Found on some Fiat, Mini and Porsche models, among others.
The distinction matters, because the protection step differs per material. Cleaning and stain removal are similar for both types.
The Ultramar 3-step plan for your convertible roof
Ultramar works with a fixed maintenance sequence: clean, remove stains, protect. These steps are not skipped and not combined. Each step has its own function.
Step 1 — Clean with Sprayhood & Tent Shampoo
Start by removing surface dirt, dust and light soiling. The shampoo cleans thoroughly, loosens the old protective layer so the protector in step 3 bonds better, and does not damage the material.
- First wet the roof with lukewarm water
- Apply the shampoo with a soft brush or sponge
- Work in straight lines following the direction of the fabric — do not scrub in circles
- Allow the product to work briefly (follow the instructions on the packaging)
- Rinse the roof thoroughly with clean water
Tip: Clean preferably in the shade or on a cloudy day. Direct sunlight causes the product to dry too quickly, which affects the result.
Step 2 — Remove stubborn stains with Power Cleaner (only if needed)
Are there still visible stains after cleaning? Think of dark discolouration, ingrained bird droppings or stubborn traffic pollution. Then use Power Cleaner — a stain remover for deeply ingrained contamination that does not come out with regular cleaning. Make sure the roof is dry before you start. If the roof already looks clean and even after step 1, skip this step.
- Apply Power Cleaner to the affected area
- Allow the product to work according to the instructions for use
- Gently brush with a soft brush
- Rinse thoroughly with water
Tip: Test Power Cleaner first on a small, inconspicuous area of the roof. This lets you check how your material reacts.
Step 3 — Protect with the right Protector
After cleaning, the roof is clean but also unprotected. The water-repellent layer has diminished through use and cleaning. By impregnating, you restore that protective effect.
The material type is decisive here:
- Fabric convertible roof (acrylic/polyester): Use Sprayhood & Tent Protector. This product restores water repellency and helps protect the fabric against the effects of moisture and dirt.
- Cotton or canvas convertible roof: Use Canvas & Cotton Protector. This product is tailored to the properties of natural fibres.
How to apply the Protector:
- Make sure the roof is completely dry — this is important for a good result
- Apply the Protector evenly over the entire surface
- Don't be too sparing: too thin a layer gives uneven protection
- Allow the roof to dry for at least 24 hours before it gets wet again
Tip: Complete the entire roof in one go. If you stop halfway and continue later, you may see differences in colour or coverage.
Common mistakes in convertible roof maintenance
- Using a pressure washer — High pressure can damage fibres and pull seams loose. Use a regular garden hose.
- Using household cleaning products — All-purpose cleaner, washing-up liquid or green soap are not designed for outdoor textiles. They can damage the coating or leave stains.
- Impregnating a wet or damp roof — The Protector does not bond well on a wet surface. The result will be uneven.
- Using too little product — Too thin a layer of Protector gives insufficient coverage. Better to use a little more than too little.
- Skipping maintenance until problems arise — Preventive maintenance is simpler and cheaper than repairing what is already damaged.
How do you recognise that your convertible roof needs maintenance?
Watch out for these signs:
- Water soaks into the fabric instead of beading off
- The roof feels damper after a shower than it used to
- You see dark stains, discolouration or a grey haze
- The fabric feels stiffer or drier than normal
- Water marks remain visible after drying
If you notice one or more of these signs, it's time for the 3-step plan.
What do you need?
For a complete maintenance treatment of your convertible roof you need:
- Sprayhood & Tent Shampoo — for cleaning
- Power Cleaner — for stubborn stains that remain after step 1
- Sprayhood & Tent Protector or Canvas & Cotton Protector — depending on your material
- A soft brush
- A garden hose or watering can with clean water
Ultramar offers maintenance bundles that combine the right products. This is often more cost-effective than buying separately and ensures you have everything you need. Check the complete range of convertible roof maintenance products for more information.
Advice on quantities: Choose a slightly larger pack than the absolute minimum. Running out of product halfway through is impractical — especially with the Protector, where even coverage matters. Extra product also comes in handy for touching up a small area later in the season or for a future maintenance treatment.
How often should you treat your convertible roof?
It depends on how you use the car and where it is kept:
- Car is often parked outside: Treating twice a year is advisable in many cases — spring and autumn.
- Car is kept in a garage: Once a year may be sufficient, depending on how often you drive and how much the roof is exposed to weather and dirt.
- After an intensive period of rain: Check whether water is still beading off properly. If not, it's time to re-protect.
Frequently asked questions
Can I treat my convertible roof in the sun?
We advise against it. Direct sunlight causes products to dry too quickly, resulting in uneven penetration. Choose a shaded spot or a cloudy day.
Do Ultramar products work on coloured roofs?
Yes, Sprayhood & Tent Shampoo and the Protector products are suitable for both black and coloured convertible roofs. If in doubt, test first on a small, inconspicuous area.
Are Ultramar products safe for home use?
Yes. All Ultramar maintenance products are designed for home use, without professional equipment or specialist knowledge. The products are also used by professionals — not because specialist knowledge is required, but because they work.
Are Ultramar products PFAS-free?
Yes. Ultramar offers PFAS-free protection products. This makes them safer for people, pets and the environment — without compromising on results.
Should I close the roof during treatment?
Yes, treat the roof in the closed position. This ensures it is fully tensioned and allows you to reach the entire surface evenly.
Summary
A well-prepared convertible roof is clean, stain-free and protected against water and dirt. With the Ultramar 3-step plan — clean, remove stains, protect — you can do this at home in an afternoon. Choose the products that suit your material, don't be too sparing and allow everything to dry properly. Then head into summer with a roof that looks well-maintained and is properly protected against whatever comes its way.