Pneumatic excavation of tree roots-what are your experiences, problems, recommendations, brands, constraints/limitations, minimal equipment necessary, fees charged...

Quick responses appreciated-as I plan to purchase an Air Spade very soon- unless there is a better tool? If you have a different recommendation please explain why you think the tool is better.

I'm posting this question in both Roots and Tools sections due to the overlap.
Nathaniel

Reply to post by Nathaniel Sperry, on September 29, 1999 at 19:31:38:

Reporting in from the edge of Nova Scotia where the only ISP is one of the 7 dwarfs and this comment box is the size of a postage stamp:

I'm not going back to look for typos?

Why the rush to get a piece of equipment>

I have extremely strong feelings about the pursuit of roots with air tools. A. What are we looking for and what purposes will it serve? B. The meaningful roots are the delicate interfaces that are mostly microscopic and will be obliterated by the air fragmentation of the soils. What will this destruction and any corresponding replacement mean to the tree?

I'm gonna go look up Air Spade and report back. In the meantime, Woodsman, woodsman, spare that air.


Tubs

Reply to post by wulkowicz, on September 29, 1999 at 19:31:38:

I guess I have the some of the same questions as Bob W. Is the excavation of roots and any particular equipment to accomplish it principally A) an investigative tool or B) a remedial tool?

If A, i) to investigate the trunk / root interface, root crown, collar or whatever you want to call it to discover structural problems or ii) to investigate the distribution of smaller roots throughout a wide root zone? If A(i), it may be a useful, minimally wounding way to accomplish the necessary soil removal. Such excavtions seem the rage in some parts of the country... but I seldom hear of them being done here in the NE. Maybe it's that we have so many rocks and so much intertwined infrastructure. Maybe it's that root rots are not as much of a problem as elsewhere (see the recent thread on the UKTC board about artificial irrigation a rot rots in California for example). Dunno... but does your volume of such work justify the acquisition cost? If A(ii), as Bob asks does the data obtained add enough to the equation to offset potential damage which may not be well understood? Just what is learned... and what what expense... that cannot be resonably well inferred from surface manifestations and rules of thumb about root distribution? "OK, now we know that roots extend outside a 'critical protection zone = 1.5x canopy radius', that we were going to respect anyway; the parking lot still has to be built at that point, sorry, put all the soil back in that critical area you've disturbed and perhaps damaged now please."

If B, for "vertical mulching" or entire root area soil replacement I suppose there is real potential. The jury still seems out on vertical mulching, some rave about it some are not so sure. Assuming either is efficacious, is compaction or poor or inappropriate soil so common in your area that you will have aenough work to make the machine pay its way? Basic business question you have to answer yourself.

You can help my understanding a litle. Is the "Air Spade" simply an output device like a nozzle and valve assembly that's secially designed for the task and couples too any suitable volume air compressor which you can rent? Or are you buying the whole works, compressor and all? Seems like that would make a big difference in the pay-back equation.

Reply to post by Scott Cullen, on September 29, 1999 at 23:45:19:

Primary use would be root crown evaluation and exposure for construction project planning.

The tool is a specialized nozzle/valve assembly that can attach to rentable compressors. Out of pocket expenses with associated hoses and options seems to be in the $2000 range.

I've talked with half a dozen arborists who've seen it in action and are very impressed with the speed and lack of apparent root damage (wish I had bold to emphasize apparent...). For example a root crown exposed in 15 minutes versus three hours of hard labor- impressive in my book.

Website is www.air-spade.com, 888-55SAFEX is the phone #

Reply to post by Nathaniel Sperry, on September 30, 1999 at 07:08:18:

I saw a demo (at ASCA conference last year) and when someone took me over he pointed out that the bark had been stripped off of roots the size of my small finger (sand blasted). Tsat might be operator error, learning curve, time of year, species, soil texture.
It seems quick and easy for root crown excavations, and as long as wee still using blowers for cleaning up, what point in stressing over the various pollution problems.
Terrill Collier in Portland has one, demo'd its use for soil replacement in Tacoma (PNW Chapter Conference.)
I would think the air would form a root-impenetrable soil interface, but I do not know. Chat with Terrill.
Peter