For our customers


Frequently asked questions & answers about cleaning and coating the greenhouse roof. Can't you find your question or do you need more information? Please don't hesitate to contact us.

Cleaning the greenhouse roof

just built a new greenhouse, so I guess I don't have to clean it for a while now, right?

Dirt also builds up quickly on a new greenhouse. One or more showers of rain will not make a difference.

How often should I brush the glass?

Vegetable growers clean their greenhouse 5 tot 15 times a year. Every percent of dirt means production loss! By brushing the glass on a regular basis, you also prevent weeds and moss from growing onto the greenhouse gutters.

I'm considering the purchase of a Top Cleaner, but I have different peak widths. Is that possible?

No, a Top Cleaner is custom-made for 1 peak width. The Safety-Cart is suitable for different peak widths though.

I'm considering the purchase of a Top Cleaner, are rails on my greenhouse necessary?

Yes, rails are necessary to ride a roof cleaner from peak to peak by means of a movement platform.

What is the weight of a Top Cleaner?

The total weight depends on the type of chosen options. In most cases, the weight is between 400 and 500 kg. A total weight of 600 kg is often allowed for new greenhouses. Please consult the builder of your greenhouse.

How strong should a service rail for a Top Cleaner be?

The standard for new greenhouses is that rails should be able to carry a weight of 1,800 kg (roof cleaner + platform + two persons).

Is the Top Cleaner safe?

The Top Cleaner complies with all relevant European safety requirements. Additional safety devices are applied for countries like Australia and North America.

I have different greenhouses. Do I have to install a roof cleaner onto every greenhouse?

No, the machines we deliver can be exchanged between different greenhouses in a quick and safe way.

I have poly greenhouses. Do you offer a machine for that too?

Yes, the Top Cleaner Poly has been developed specifically for poly greenhouses.

Can I also use the roof cleaner to replace broken windows?

No, the machine is not suitable for that. We advise purchasing a Repair Shuttle for that

I would like to apply a coating onto the greenhouse. Can I do that with a roof cleaner?

Yes, a set of spray booms is available as an option for both the Safety-Cart, the Top Cleaner and the Top Cleaner Poly.

Can I hang a roof cleaner onto the greenhouse throughout the year?

Yes, basically you can. However, you do have to take measures in the event of frost and you should consider placing the machine somewhere inside in the event of extreme low temperatures.

My greenhouse gutters have a length of 300 metres. Can the Top Cleaner wash these as well?

It sure can. A Top Cleaner can hold about 350 metres of hose. The weight of the roof cleaner does increase with that, of course.

How much water does a Top Cleaner use?

About 5,000 litres of water per hectare.

Does Van der Waay offer a machine that cleans the inside of the glass as well?

The AquaJet is the perfect solution for that. This roof cleaner cleans the greenhouse roof, the facades and even the crop gutters.

Coating the greenhouse roof

Can you also spray powder chalk with a machine?

No, we advise against that. Powder chalk settles too fast and will clog the nozzles of the spray booms.

What coatings can I spray with a roof cleaner?

You can basically use every liquid coating you desire, provided that it is mixed with water in the right way.

How much coating should I spray?

Please ask your supplier. The needed amount of spray liquid (coating + water) per hectare is about 1,300 litres.

How do I calculate the right supply of spray liquid?

The supply depends on multiple factors; the water pressure of the nozzles, the riding speed of the machine and the size of the nozzles. Please don't hesitate to ask us, because we would love to help you calculate the right amount.

Do I need a special pump to spray coatings with?

Yes. Not every pump is suitable. Van der Waay provides pump sets that are specifically made for mixing and spraying coatings and these are equipped with; a membrane pump, mixing barrel with rudder and hose reel.