Considerations For A Stable & Lasting Base

By Grove Teates

Alpine Services, Inc.

•There have been major advances in technology since inception, re: turf and seaming

•In today’s world, most of the turf field problems are base related

•It is a good idea to examine bases and their construction elements

•Names have been changed to protect the guilty

We have observed the industry since its beginning

Usual Procurement Procedure

•Owner hires engineer/architect to design bid documents

•Owner decides to build a turf field

•Job is bid/Invite proposals for job

•Bids are based upon specifications provided by owner/architect

•Specifications determine quality & price of field base

•Therefore specifications must be important

“State-of-the-art” specifications from actual jobs put out to bid

“Finish grades shall be verified using laser operation survey instruments with a tolerance of +/- ¼”. A survey of the finish spot grades is to be

developed by a licensed surveyor over the entire surface in the form of a grid at 25’ spacings in two directions.”—a stadium soccer field

“Grade all areas to a smooth, free draining and even surface with loose uniform fine texture. Roll and rake to remove ridges and fill depressions as

required to drain.” -7 fields in a Delaware High School Complex

“Install a 4” layer of drainage gravel in areas of the playing field to receiveRoot zone mix and turf. Establish smooth, true lines to an elevation 8”

below final field elevation.” –a nationally known field architect

--Continued

“Variances shall not exceed 0.05’ when tested with a 10’ straight edge”.--the same architect

“The infield will require a 0.5% slope from home plate to the outfieldarea.—a well known university in West Virginia

“Reform the surface with a hydraulic land plane.” --a PA architectfor a college

“Grade tolerances for athletic fields shall be held at ¼” per foot.” --the Same PA architect for a 5 field complex

--Continued

“The playing field at the stadium shall be re-graded to lower the center of thefield by 6”, to a more level playing surface. The center shall be excavated

and the field graded to provide drainage after grading.” -- MD University Bid

The truth is stranger than fiction—aren’t these

impressive!!!

Good Specifications

•State what the desired end result will be

•Give the tolerances

•Give specific instruction for various areas/applications, i.e., sub-base,intermediate surface, final surface, bottom of drain ditches, etc.

•Provide a reliable standard which allows items to be judgedMust be appropriate to the issue:

Stone compaction vs. soil compactionStone grading capabilities vs. particle size

•Can include work experience at each contractor labor level

•Should specify that the experience of individuals cannot be combined to show exaggerated company experience

--Continued

•Can specify that equipment must be owned vs. rented

•Should specify the accuracy of the laser equipment—readers and sources

Critique of “State-of-the-art Grading Specifications”

The central core issue of good grading specifications is vertical distance

measured over a horizontal distance, when measured from the absolute plane

“Finish grades shall be verified using laser operation survey instrumentswith a tolerance of +/- ¼”. A survey of the finished spot grades is to be developed by a licensed surveyor over the entire surface in the formof a grid at 25’ spacings in two directions.”

Most survey instruments do not use lasers+/- ¼” does not mean anything, and anything goes with this

--Continued

“Reform the surface with a hydraulic land plane.” This is totally non-descriptiveThe field is in compliance when one drives a land

plane over it?????“Grade tolerance for athletic fields shall be held at ¼” per foot.”

There is no mention of a reference¼” deviation per foot is 7.5’ (1/4”x360=90”/12=7.5’) acceptable deviation.Another mountain state field?

“The playing field at the …stadium shall be re-graded to lower the center of the field by 6”, to a more level playing surface. The center shall be excavated and the field graded to provide drainage after grading.”

“More level” is highly descriptive but not very informative

--Continued

“Grade all areas to a smooth, free draining and even surface with loose uniform fine texture. Roll and rake to remove ridges and filldepressions as required to drain”

What is “smooth & free draining?What is the slope, where does the water go, etc.

What about compaction before/after grading

--Continued

“Install 4” layer of drainage gravel in areas of the playing field to receiveroot zone mix and turf. Establish smooth, true lines to an elevation 8”below final field elevation”.

Gravel can be anything handy“Rootzone” is mixed with “stone drainage” –wrong wordingWhat is smooth & true, what is the slope, etc.This is an argument/lawsuit in the making

“Variances shall not exceed 0.05’ when tested with a 10’ straight edge.”No reference what the .05’ is measured from.05’ within 10’ is a bad requirement, almost anything goesThis allows a 18” (360’/10 x ½”) variance and the field willstill be within specification—you will have to accept it or pay for it.

Vendor benefits of Good Specifications

•A good product benefits everyone in the industry, sells more fields and enhances the desirability of owning a synthetic turf field

•Proven drainage is a strong positive reinforcement of the decision to purchase a synthetic field

•There is more “social security” for the sales agent, easier to sell the next job

•Good specifications are a great sales tool at the time of job solicitation

In Reality!!

Good Specifications must address:

•Sub-base specifications, re-planarity, tolerance, grade, etc.

•Intermediate layer between different size stone—grade, compaction

•Finish grade and surface—equipment tracks, finish, etc.

•Checking method—high-tech method

•Material grading capabilities—stone, soil, sand, etc.

•Compaction of various materials

Random Observations

Bases are stone-filled pools if they do not have drains

Test flat drains before selecting a brandPerched water on the sub-base

Grooving

Drain flow rates vs. pipe sizeslaterals

PerimetersSmall pipe reduces costs on several fronts

Pipe size vs. backfill shadow

--Continued

Installation practices are important

Driving in the same place

Type of roller to use

Roll through the rug?

Surface stone—what type?Laser techniques-pole and target

Spearin Doctrine—very importantThe Spearin Doctrine is the legal principle that holds that when a

contractor follows the plans and specifications furnished by the owner, and those plans and specifications turn out to be defective or insufficient, the contractor is not liable to the owner for any loss or damage resulting from the defective plans and specifications.

Summary

The industry needs to improve the performance of the end product by improving the base construction.

Good specifications enhance the chances of improvement in fields andimage

Techniques are important!

The Spearin Doctrine is important!

Questions??

Grade Tolerance

Ditch Bottoms

Owned Grader

Bad Base

Pipe Shadow