A surface cleaner is the single biggest time saver on flatwork. It is also the easiest thing to buy wrong, because people size it to the job instead of to the machine.
Your machine decides the size, not the driveway
A surface cleaner spins bars with nozzles on them. Those nozzles need a certain flow to maintain pressure. Put a big cleaner on a small machine and the pressure at each nozzle drops, so you get a weak, streaky clean and you go over everything twice.
Rough guide:
- Around 4 GPM. 16 inch. Stay small, you do not have the flow to feed anything bigger.
- 5 to 5.5 GPM. 20 inch. See the 20 in. Whirl-A-Way or the Pro Force 20 in.
- 8 GPM. 24 inch. The 24 in. Whirl-A-Way or the Pro Force 24 in.
- 10 GPM and up. 28 to 30 inch. The Big Guy 28 in. or the 30 in. Whirl-A-Way.
Browse the full range in surface cleaners.
Bigger is not automatically faster
A 28 inch head on a 5 GPM machine covers more ground per pass but cleans worse, so you do two passes and finish slower than a 20 inch would have. Match the head to the flow and you do one pass.
Things that matter beyond diameter
- Casters. On rough or sloped concrete, casters keep the head level and stop it digging in. Worth it on anything 20 inch and up.
- Deck material. Stainless lasts, aluminium is lighter. If you are lifting it in and out of a truck all day, weight is a real consideration.
- Swivel. This is the wear part. It will need a rebuild eventually, so buy a model you can actually get parts for.
- Nozzles. Worn tips are the usual reason a cleaner that used to be good starts leaving stripes. Replacing them is cheap, see nozzles and tips.
If it leaves stripes
Check in this order: worn nozzles, a swivel that is not spinning freely, too little flow for the head size, and moving too fast. It is almost always one of those four, and usually the first.