12V softwash pump for roof cleaining

I’ve done a lot of searching and research on this site, but haven’t found a definite answer. I’m looking for a 12V pump to build a softwash system. It will not be used on a daily basis, but I’m still looking for a decent quality pump. My question is, are “on demand” pumps or “bypass” pumps best for this application? Also, is there any major advantage to a 7gpm vs. 5.5gpm pump other than time savings. Finally is there a consensus on the best manufacturer and pump for this application.

Delavan is pretty much the industry standard. You will want an “on demand” pump and the advantage of a higher flow pump is exactly what you stated, efficiency and more distance. FYI the pump’s output is about 50% of rated after going through 200’-300’ of hose.

Northern Tool runs some good sales on their pumps occasionally, I’ve got a couple and they work great.

Thanks for the reply Pristine! I had looked at the Northstar pumps from Northern since several on the forum were using them. My concern was comments on line from Northern Tool saying none of their 12v pumps were designed for use with SH. Maybe it’s just a CYA statement from them.

I’d go with Delavan if you’re serious about roof washing. I only use NT pumps for SH transfer and as emergency backup. FYI all 12v diaphragm pumps are considered disposable as bleach is tough on the pump head. Just make sure you have a backup pump on hand if you decide to go 12v.