AU2007100976A4 - Durable soil coating & application process - Google Patents

Description

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1O 00 1°oo COMMONWEALTH OF AUSTRALIA COMPLETE SPECIFICATION INNOVATION PATENT Title: Durable Soil Coating and Application Process Applicant: Peter Arthur Cole Application Date: 6th October 2007 Peter Cole: 14 Garden Road Camberwell Victoria 3124 Phone: (03) 9809 1667 Mobile Telephone: 0419 517729 Email: mdewitt@bigpond.com

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION INNOVATION PATENT for the invention entitled: "Durable Soil Coating and Application Process" The following statement is a full description of this invention, including the best method of performing it known to me: Durable Soil Coating and Application Process Field of the Invention C This invention deals with an effectively new product for the gardening landscaping industry.

O 5 It relates to the process of applying a coating of GRC (glass-reinforced cement) over soil in an I inventive manner, transforming the GRC into a product that enables it to blend in with the IDsoil. The invention, "Toughcoat" (TM) thus provides a new alternative form of "mulch" for 1the gardening industry. Variations to the principal process provide additional benefits.

E Background of the Invention S 10 Mulches of various kinds are applied to the soil-surfaces of gardens for a range of purposes.

I" These are generally to assist with moisture preservation in the soil, weed prevention, disguising of "garden utilities" such as drip-watering plumbing, to retain soil slopes in a few cases and to improve the aeration and fertilisation of the soil for better plant health. Their i appearance is not unattractive at the very least, thus blending-in with the garden satisfactorily.

This invention concerns itself with the shortcomings of existing mulches, relating to the first I four of their abovementioned properties, and overcoming their failings by applying a newlyinvented form of GRC, "Toughcoat", created by the application of the invented process.

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Mulches can be grouped into two categories: organic (which is the predominant category) and I inorganic. Organic mulches, of lawn clippings, pine bark, ground-up plants and trees, etc, particularly but not exclusively when degrading to a significant degree, fail to provide the I abovementioned benefits of moisture preservation in the soil, weed prevention and disguising of "garden utilities", to a satisfactory level. Also by their nature they fail in certain Sapplications when applied ab initio: On any significant slope the particulate matter of mulch fails to hold well, being blown off by wind or washed off by rain. In any terrain, whether flat I 25 or sloping, and especially when initially laid down, particulate-mulch is apt to be scattered by birds and other animals foraging underneath it. The mulches' attractiveness and thus purpose, I correspondingly diminishes in all the above degradation circumstances.

All the above failings are overcome by the application of a coating of GRC over the soil, since it is basically non-degradable like concrete, it is essentially completely weed-proof, it I 30 holds up on slopes and it resists disintegration by animals. However having its usual artificial appearance, the use of GRC for the described purposes would rarely if ever be countenanced 1 2 being as it is completely unsympathetic with the garden's natural appearance. Hence the 18 invented process to overcome this fundamental objection.

(I Inorganic mulches fall broadly into two subcategories: particulate hard mulch, like C 5 river-pebbles, which fill the same role as inorganic mulches; and blanket-like coverings over I the soil, like sheet plastic, which aim principally to hold disturbed soil on steep slopes and D with a secondary benefit of moisture-retention. The former type does not hold well on slopes, r and even when laid on flat terrain its rough texture readily attracts and retains wind-blown soil and leaves etc., thereby quickly losing its attractiveness and encouraging weed growth I 10 unless assiduously maintained. By contrast the Toughcoat surface achieved through the invented process does not accumulate soil and leaves readily when laid on flat terrain. And in contrast to particulate hard mulch, the Toughcoat surfacing does hold up well on slopes.

I The latter 'blanket-covering' type of hard mulch is useful particularly over a large area, where it has cost and application-speed advantages over the invented Toughcoat, such that the S 15 invented process would not produce a competitive alternative. On smaller, more highly valued areas the superior attractiveness of the augmented GRC combined with its superior durability I may prove an attractive alternative, since the subject hard mulch is unattractive, especially while degrading. There are in fact also organic mats used for the soil-retaining purpose, which I look less unattractive than their plastic counterparts, but only to a degree; while their decaying stages look similarly unappealing, and exhibit most of the other failings of organic mulch.

A further advantage exclusive to GRC over all commonly-used mulches is its ability to retain I soil in sculpted forms; hills and gullies, terraces, and so forth, and to hold in place rocks and other heavy items up to considerable weight in place, on the soil surface. This ability to shape I and retain the soil for an indefinite period opens up a whole new creative-realm for the home gardener and professional. Watercourses may also be present in the creative GRC landscape, I using additional waterproofing methods. As before, the essential unattractiveness of GRC is overcome using the invention. (Note that GRC's ability to withstand stresses like continuous Ifoot-traffic is limited when laid over uncompacted soil.) I The invented "Toughcoat" therefore provides an attractive and better-functioning alternative to existing mulches in many cases. To summarise: it does not decompose, it prohibits weeds indefinitely, it permanently hides plumbing underneath its coating, it resists all but the most

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tq Io I oc, 3 determined attacks on it by animals, it holds up against wind and water, and it retains slopes in their desired positions: and as such facilitates new creative possibilities for the applicator.

Individuals' preferences, higher cost and slower speed of application may, however, weigh 5 the decision against its use. Additionally, the precautions often needed to reduce the impact of its alkalinity, may dissuade potential users.

I 0 I~o Disclosure of the Invention The invention provides steps in a process to produce a natural looking durable soil coating and the resultant creation of the first viable, essentially 'permanent mulch-coating' for soil.

I N The main aim of the invented process is to, as quickly as aesthetically possible, texture the raw GRC surface into the semblance of soil or similar natural-looking surface. GRC in its usual form is fibrous and jagged on its applied surface, due to the chopped-strand glass fibres protruding from its surface, or is otherwise usually flattened and compacted with a rolling device resulting in a finely corrugated surface; neither of which has a likeness to any naturally-occurring soil surface in nature.

The invented process achieves this "natural look" aim as quickly as possible by, in the main aspect but not exclusively, the combining of two steps into one: the flattening of the glass fibres and the imparting of a soil-like texture. A basically friable soil is sprinkled or thrown onto the newly-laid GRC surface, and "patted in" in most cases for speed and convenience by a large brush in its preferred embodiment, which achieves both the desired flattening of the fibres, and the imparting of a soil-like texture in the one motion.

A secondary aim is to impart suitable colour to the surface, again for purposes of achieving as natural a look to the surface as possible. That aim is achieved by a specific invented combination of standard processes, to produce the unique "Toughcoat" appearance. Initially pigments or similar colouring agents are mixed into the GRC. In its preferred embodiment, the pigment-enriched GRC is usually to be set at a quicker-than-normal speed, the better to bind-in the milky mineral salt compound known as "laitance". If not combated, laitance occurs at the GRC surface, appearing far more readily than other cementitious products due to the invention's high cement content and high degree of "working" of the surface. Laitance dulls existing surface-colours by overlaying a whitish-residue, somewhat reminiscent of frost.

1 4 To further discourage laitance, standard procedures for best-setting cementitious products in an on-site location are used, namely the covering of the worked surface with an impermeable membrane and ideally also moisture-rich membrane. Such membranes substantially reduce evaporation at the surface of the GRC thereby reducing the ability of the materials involved in O laitance to migrate along with the water to the surface, and there be deposited as the water evaporates. The high RH environment created also encourages more complete setting of the being concentrated at the surface.

In circumstances where excessive laitance appears despite best efforts, available proprietary i sealing colour enhancing products are applied in a unique way to largely restore the desired surface appearance.

I In other, slower-applied, embodiments of the process the GRC surface may, for example, Shave a bulkier cementitious layer not containing fibreglass, laid over it, which is similarly coloured, and protected from laitance, and may be "rock-textured" or similar whilst setting.

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Brief Description of the Drawings The drawings show the properties and application methods of the GRC-soil coating, j transforming GRC into a feasible product for gardens.

S 20 Figure 1 shows broadly the constructive properties of GRC when applied over soil.

I Figure 2 more specifically demonstrates the appearance and versatility of the Toughcoat surfacing which results from the invented process.

I Figure 3 shows the dynamic application process.

I Figure 4 shows two possible variations to the main process.

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1 r Detailed Description of the Preferred Embodiments Figure 1 gives a pictorial description of the properties of GRC the underlying product that I O is altered by the invented process. We see a thin, strong, light-weight (due to its thinness of 00 5 application) surfacing which can retain both lightly-compacted soil, and heavy rocks, in their j originally-placed positions and on a variety of angles including undercuts. This versatility is IO not possible using thick concrete (which would collapse soft or undercut soil) nor would such r- >versatility be possible using wire-reinforced cement, and it also takes longer to fabricate.

I Referring to Figure 2: a natural-looking surface has been invented from the process. Its S 10 creative soil-shaping/planting potential is shown. Fig. 2 demonstrates the hiding of the I drip-watering plumbing; and the re-shaping of the original soil profile for, in the pictured case, the benefit of terracing the soil which thus facilitates an ideal even-watering of the plant, I and demonstrates the plant's consequently more attractive prominence in the landscape.

I Figure 3 shows at 1 the GRC surface laid down; and at 2 the soil or similar surfacing laid on top. At 3 and 4 we see typical implements used in the process. The invented process is now to Sbe described in more detail, in step form, immediately below.

I Preliminary step A GRC mix is made, of around one and a half parts cement/ one part sand/ and approaching one part alkali-resistant fibreglass. It is mixed with water to make a Sslurry of a consistency somewhat more viscous than brick-layer's mortar.

Preliminary step The soil over which the GRC is to be applied is to be thoroughly moistened, to form a sufficient keying-surface for the GRC, and to encourage as slow a set as I possible at the soil's interface, thereby producing a stronger membrane. Steep surfaces and/or sandy and/or dry soil surfaces may need to be overlaid with moistened hessian or other robust I moisture-retaining membrane, so the GRC mix will not slough-off such surfaces.

S 25 Step 1: Pigment is added to more closely-resemble soil or similar natural ground surface. If in powder form, it is generally around 10% of the volume of the cement, although lesser and I greater concentrations may be preferred.

Except in warm or hot climatic conditions where cement-setting already occurs rapidly, I cement-set-accelerator is preferably but not necessarily added to the water for the GRC, at a

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rate depending on the temperature which will ideally firm-set the mix in approximately fifteen to thirty minutes. This measure is recommended in order to reduce creation and migration of laitance by binding it in the bulk of the set-GRC mix rather than it appearing on the surface of O the GRC, where it could dull, if not overwhelm, the applied colouring. The GRC material is particularly susceptible to laitance, having a high cement content, and furthermore since it is applied thinly has a tendency to evaporate proportionately more quickly through its substance, IND therefore being correspondingly more inclined to drag laitance minerals to the surface.

An option when colouring the GRC is to separate the mix into two or more containers, and differentially colour each with the aim, when applying it to the soil surface, of blending a i range of colours on said surface, thereby producing even more natural-looking appearance.

I Step 2: The GRC material, preferably but not essentially coloured, is applied to the soil surface. Ideally but not critically a pause of around 1 to 6 minutes is optimal. This time-range can vary significantly depending on the ambient temperature and wind, but the aim of the pause is to facilitate a partial-set of the GRC's upper surface. The partial-set begins to bind free water into the GRC surface. Such setting enables the second layer of soil to better-sit on the GRC surface, and be less puddled-into the mix when the brush or other compacting agent Sstipples it (see step 3 for more detail). Additionally, the less free water on the surface, the less laitance will be created when the GRC is agitated during the soil-layer stippling process.

Step 3: The soil layer is applied, generally by sprinkling or throwing, onto the GRC. A lightly-moist sandy loam exemplifies the ideal conditions: it can be distributed homogenously, it is not so dry as to draw the moisture (and accompanying laitance) out from the GRC quickly, and it has an even-grain that conveys the appearance of soil convincingly.

A range of other soils is however, still acceptable in creating the desired effect; but the closer 3 25 the soil resembles the ideal, the more successful it will be. Clay soils of not too-lumpy a consistency can impart a texture of character, for example. Too large-lumps will unduly 3 disrupt the GRC however, and may not bind into the GRC layer.

SThe soil layer is then patted gently into the GRC layer with such strength and/or repetition that a significant proportion of it will bind to the GRC layer. Normally around 50% of the soil applied is bound, which subsequently produces the hardened-soil-like appearance or similar.

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The patting of the soil should also be of the strength and/or repetition such that it forces most of the chopped-strand fibreglass into the bulk of the mix, rather than it remaining poking out: an essential component of the realistic-looking surfacing. The thickness of the applied soil has a bearing on the success of the fibreglass-suppression: too thin a layer of soil (approximately less than 1.5mm), may not have the bulk to force the glass down. If the soil layer does not provide a thick enough buffer for the brush, the brush will pass through it and become mired in the GRC mix: disrupting the natural-looking texture, and encouraging laitance. If too thick a soil layer is applied (say over 3.5mm), there may be too bulky a buffer between brush and 0 GRC layer, which diminishes the force of the brush and may not compress all the glass fibres into the surface of the mixture.

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Step 4: The brush ideally but not essentially should be rid of clinging GRC regularly, or a new brush used, so that it may maintain its role of patting the soil layer. If not, the brush becomes damp and sticky, clinging to and paddling in the GRC surface, thus disrupting the natural look of the surface and encouraging laitance.

SStep 5: Surfaces when set to a tough consistency can then have moist hessian matting or similar materials laid on them, followed by sheets of a moisture-impermeable membrane like plastic, for the purposes of discouraging laitance, as previously discussed.

Step 6: In some cases laitance will appear despite one's best efforts to keep it at bay. Such occasions are more likely to occur in damp conditions, and the application of the invented Sprocess should ideally be delayed for more clement conditions. However, the subsequent application of a 'slate sealer' or similar surfacing material, applied as soon as possible after I the Toughcoat has set, will markedly diminish the appearance of laitance and restore colour.

To maintain a realistic appearance to the invented coating, an uninterrupted coating of sealer is necessary. To that end, any loosely-adhering soil is first to be brushed off; which also reduces the contamination and therefore maximises efficacy of the applied sealer.

I Figure 4 shows two possible variations to the main process: a rock-texture being applied and Sgrooved, or equally the lumpier texture of any of nutrient/cement/soil/manure/moss mix, designed to adhere to the un-set GRC substrate while encouraging the rapid growth of moss or similar plants over its surface.

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Whilst the above description includes the preferred embodiments of the invention, it is to be understood that many variations, alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the essential features or the spirit or ambit of the invention.

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It will also be understood that where the word "comprises" or "includes" or similar collective words are used in this specification, unless the context requires otherwise such use is intended to imply the inclusion of a stated feature or features but is not to be taken as excluding the presence of other feature or features.

Dated this 6th day of October 2007 Peter Arthur Cole

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Claims (2)

1. 2. The durable natural-looking coating of claim 1, constituted of GRC (Glass-Reinforced Cement) wherein the properties of GRC can for the first time be effectively utilised for the garden-enhancing-mulching purposes to which the coating is applied due to the processes disclosed: broadly by the addition of a soil or similar layer over the GRC, worked into the I surface in the prescribed manner.
2. 3. The durable natural-looking coating of claim 1, whose method of application provides for I maximum economies of time and cost. I 4. The durable natural-looking coating of claim 3, whereby the surface achieved is maintained by a specific combination of application processes. I The durable natural-looking coating of claim 3, with variations to the applied surface to produce alternative appearances of moss-covering, rock-surfacing, etc.