Job: Twycross zoo

Area: 3300m2

Grid: Gridforce GF30

Installation of a Resin bound pathway using

Gridforce at Twycross Zoo

The Problem

The pathways between animal enclosures around Twycross Zoo had become rutted and muddy with the

high amount of pedestrian traffic they received on a daily basis. The Zoo decided they needed a

permeable solution which was durable and aesthetically pleasing but maintenance free.

The Solution

After speaking to Future Contractors Ltd about possible solutions,

the Zoo decided the best route to go down would be using

Gridforce GF30, a strong and robust paver in unison with a resin

bound top. A resin bound surface is essentially gravel or stone

bound with resin to give it a smooth, yet textured finish giving the

appearance of “loose gravel”. This means that the finished product

would be a fully compliant sustainable drainage system and also

maintenance free as the aggregate is bound on top.

The build-up was as follows:

MOT Type 3

Non-woven geotextile

30mm of 6mm hard angular gravel bedding layer

Gridforce GF30

6mm aggregate infill

Resin bound top

Step 1

Dig out and remove the existing path way down to substrate. The amount removed is dependent on the

ground characteristics and therefore the depth of the drainage material needed. The worse the ground

condition, the more MOT Type 3 (drainage media) is needed for the rain water to filter through.

Additionally, if the ground contains any soft sports a geogrid may be used for reinforcement; luckily this

was not needed at Tywcross zoo.

Step 5

Lay the Gridforce GF30 pavers starting in one corner and fanning out. Two workers can lay 100m2 in an

hour with the quick lug and slot clipping system.

Step 2

Lay and compact MOT Type

3. This is a 40mm product

that has been screened to

create a reduced fines

aggregate (not zero fines.)

This allows the rain water to

filter through and return to

the water table semi purified.

Step 3

Lay a non-woven

geotextile. This is used as a

separating layer and a

weed suppressant.

Step 4

Top with 30mm sharp

sand/6mm grit. This acts

as a bedding layer for the

Gridforce and stops any

aggregate getting

underneath the pavers &

lifting them

Step 6

As above, for a resin finish infill pavers with a 6mm aggregate and compact well into the cells

Resin bound stone should not be confused with resin bonded

stone, bound in simple terms means that the aggregate and

fines are firmly joined together with a robust system which

actually has 20% voids, therefore allowing water and fine

detritus to pass freely through.

Step 7

Top the filled cells with the resin top The resin bound top

involves mixing the aggregates (typically 2-5mm) together

with the resin in a forced action mixer. The mixed material is

then taken from the mixer, poured on to the surface, raked

out and then finished with a trowel to leave a flat surface to a

thickness of 20mm.

Using a resin bound surface with

Gridforce provides the following

advantages:

SUDS compliant

Durable

UV stable

Low maintenance

Anti-slip

Wheelchair friendly

In conclusion

The whole area of 3300m2 was finished within 14 weeks from start to finish which met the completion for

the start of the peak season; future contractors also managed to keep the site accessible by dividing the

works into 2 phases. The Zoo is incredibly happy with the finished project and the quality of work

completed.