First United-CS010708 DOWDEY, ANDERSON AND ASSOCIATES, INC.
CIVIL ENGINEERS
5225 VILLAGE CREEK DRIVE SUITE 200
PLANO, TEXAS 75093
(972) 931-0694 FAX (972) 931-9538
MEMO FOR RECORD
7/8/01
DAA Job No. 96-081
TO: Mr. Ken Griffin, P.E.
City of Coppell
FROM: William A. Anderson, P.E.
CC: First united Methodist Church..z.,Fiie
RE: Final Report for First United Methodist Church Parking Lot
In accordance with Zoning Case No. S - 1137R First United Methodist Church, I am
hereby submitting a final report that assesses the alternate paving material that was
installed previously on the site.
Introduction:
The existing site is bounded by Heartz Road on the east, Vanbebber Road on the north
and Bethel School Road on the south. The parking lot is currently approximately 2.6
acres in a square pattern.
The parking lot currently accommodates 229 spaces. No parking is allowed along Heartz
Road adjacent to the site. The parking lot is an accessory use to the church, which is
located on the eastern side of Heartz Road. The perimeter streets are concrete. Bethel
School Road is in below average condition. Heartz Road and Vanbebber Road are in
above average conditions. The adjacent uses to the property (north and south) are
residential. The parking lot is predominateiy used by the congregation on Sunday
mornings. Rarely is the parking lot fully utilized. It is noted that many members choose
to park along Vanbebber Road and on a section of Heartz Road north of the site rather
than in the parking lot.
Site Characteristics:
The site is relatively flat (1% slope) draining in all directions. The soil is naturally clay.
The surrounding streets have curb and gutter sections with an underground storm sewer
system.
Prior to development of the site, a pond was located at the northeast comer. Based on the
current pavement, there is no noticeable effect due to the previous pond.
There are landscape islands located throughout the existing site. Both the islands and the
site are irrigated. Due to wear, the drive lanes are denuded of grass. The parking spaces
have grass but need additional grounds keeping.
Upon examination during and after rain, several rutted areas were noticed. Near the
entrance and along some fire lane/drive isles.
Existing Material:
The material chosen as a base course for this site is a proprietary mix that is granular in
nature. It is my understanding that the material is a heated clay product that when heated
to a predetermined temperature crystallizes into a granular material that appears like a
porous crushed rock composition.
The subgrade is compacted to 95% standard proctor density at optimum moisture, a
geogrid tensor material is placed immediately on the subgrade, two inches of crushed
limestone rock (2 Grade) is placed, then four inches of proprietary mix is added. A nylon
grid is placed above the proprietary mix. The final surface is a Bermuda block sod (419
Tiff Variety).
Site Performance:
The site has been monitored since installation. Several issues were noticed almost
immediately. They are as follows:
1. Block sod creates an immediate finished look however; block sod has a clayey
backing of approximately one inch in thickness. The problem with the clayey
backing is that when wet, it tends to turn to mud. With the solid base, said
mud penetrates through the grass surface. There is no practical place for said
clay to disperse.
2. The proprietary mix appeared to withstand the traffic even though the grass
was worn away. The mix failed at turning locations, at the drive approaches
adjacent to concrete and in some drive lanes. It did not appear to fail in the
parking places.
3. The site appeared to be poorly maintained. Weeds were in the islands and all
areas appeared to lack adequate water.
4. The previously noted rutted areas did not appear to be regularly maintained.
5. Striping in the parking lot was not present.
6. The site appeared to drain properly.
Conclusion:
The site should not have had block sod installed, which created a clay membrane that was
not able to disperse. The site did not appear to be maintained, i.e. water, repaired
adequately. The site was deemed labor intensive to maintain from watering, striping,
deweeding, material repairs and lacked a general aesthetically pleasing use. Members of
the church would not regularly park in the lot during or after a rain event. The material
could be used for overflow parking such as State Fairs, Christmas shopping, peak areas in
shopping centers and for fire lanes that are seldom used in lieu of concrete or grasscrete.
I would not recommend this application for this type use with the circumstances outlined
above. This product has potential but it needs a tremendous amount of attention for a
church parking lot application.
R:~Data\1996\9608 I~ME, MO FOR RECORD.K. Griffin doc