Question 1

Does Landscape Tanks™ arrange and perform installations?

Accepted Answer

No.  Installation is simple and can be done by anyone and any trade.  It is cheaper, faster and better, in our experience, for your builder, landscaper or you, to do the installation yourself.  “DIY” installation is not our preference.

Disciplined and thorough trades people are quickly and easily able to understand our tanks and their installation requirements.  In our experience, it’s far better, cheaper and less stressful, to hand the installation to a good trades person who knows your site, your locality (access, parking etc), is able to co-ordinate the installation with other works so they don’t clash and so your installer has seamless and trouble free control of all works.  If your installation is part of a landscaping project, our advice is, give the installation of our tanks to your landscaper.  If your installation is part of a house build, our advice is, give the installation to your builder.

Its usual for customers to incorporate the installation under the umbrella of other associated works.  The most usual installers are in order, builders, plumbers and landscapers, DIY’s and earth moving contractors.

Question 2

Do I need any particular trade (plumber etc) present at installation?

Accepted Answer

Only one, a heavy equipment operator.  You need lifting equipment and an operator for it, along with suitable ground staff to align and level the tanks.  You don’t need a plumber present and there is no water testing required to be done at installation or after.

All internal plumbing (connecting and outlet PVC pipe) is provided with the tanks.  Installation of the internal plumbing is “check the seal, lubricate (preferable, not compulsory), push in, jiggle and leave”.  Simple and literally seconds to complete.  The only tools needed are a ladder and a can of silicone spray (for lubrication of the seal prior to pipe insertion; a preference but not compulsory), and of course the agility to be able to get into and then out of the tank.

All external plumbing can be performed at a time that suits your project and plumber’s schedule (diary).  This saves you money as your plumber can do these works at a time that suits and in combination with and at a time compatible with other plumbing works.  Like the internal plumbing the connection to external plumbing (inlet from your catchment area; normally your roof) is “check the seal, lubricate (preferable, not compulsory), push in, jiggle and leave”.

Question 3

Does Landscape Tanks™ deliver to site?

Accepted Answer

No.  It’s really clear from our experience that the best outcomes are achieved where the installation and delivery are co-ordinated by someone who knows your site, the locality (local conditions, road, parking, traffic, best routes) and installation arrangements.  Freight companies will add margin where they become uncertain over the ability to quickly enter, unload and exit a site.  Site and locality knowledge, allow for quick and hassle-free unloading. Carriers become more confident and are able to be more price aggressive where they are able to ask questions and get firm, correct and an immediate, response.  Only someone with intimate knowledge of the locality, site and installation can provide that level of assurance.  In addition to the reasons above, while we are very responsive to client requests, it’s clear that there is no benefit or upside in us being a post office box who’s only purpose is to ferry messages between the carrier and your installer, particularly where something we are unaware of has happened, for example sudden and unexpected bad weather.

We provide details of carriers we recommend. These carriers have provided us with quotes to pegged points from our factory, namely, Sydney, Melbourne, Brisbane, Adelaide, Canberra CBD’s. The contacts at each of these carriers know you have these quotes in your possession when you contact them.We only deal with reliable carriers who know our tanks and provide good reliable customer service.

Question 4

Do you supply and or sell pumps?

Accepted Answer

No.  It’s cheaper, easier, especially for warranty purposes, to source a pump locally. Our experience is that you can source a good quality plump for a very reasonable price, anywhere and it will have or you can cheaply add, all the extra’s you could require (for example, automatic no flow powering off).

We don’t recommend submersible pumps for our tanks even though it is possible to install a submersible pump into the tanks. The simple reason for this is maintenance of a submersible requires access and to have access, you either have to bring in heavy equipment to remove the planter or have an access hatch in the planter box which adds cost and decreases appeal.

Question 5

How do I retain the earth behind the tanks?

Accepted Answer

As you would for any other retaining wall.  The tanks are designed to retain earth in accordance with and to meet all relevant Australian Standards and good practice.  All general “retaining wall” practices (spoon drain, crushed rock, perforated drain and silt sock etc), apply.  There is no additional “retaining” processes that you need to do or complete, to accommodate the tanks.  Carry out processes as you would have, had the retaining wall been made of block, reinforcement and concrete fill.

Landscape Tanks™ or your engineer can provide you with specific back fill levels and the allowable maximum “angle of repose”.  Contact us by email operations@landscapetanks.com.au for a copy of our standard engineering.

The tanks are structural and a significant piece of kit. They are designed to take load externally from earth inwards, from one or more sides, while the tank is full or empty, along with accommodate load outwards from water without “other” external support.

Question 6

What site preparation is required?

Accepted Answer

Minimal.  You need to cut to clear, clean, soil.  You need to have not less than 100 kPa soil firmness for the tank’s footprint (plus a suitable margin).  100 kPa generally is easily achieved for most sites.  All other good earth works preparation processes apply, for example, there is to be no rubbish, decaying plant or other matter left in situ and there needs to be consistency across the platform you have prepared.

The only tank specific site preparation requirement is 50mm of class 3 crushed rock or road base, which is to be screed flat and compacted.

The low site preparedness (obligations) is one of the great advantages of our system.  The tanks are designed to have structural integrity so that they can effectively stand alone and hold both water and earth at the same time from a based firmness easily achieved at most sites.  This said, it would be wrong to think the tanks are impervious to all manner of rushed / poor preparation and or poor soil condition.

Question 7

Can the tanks go underground?

Accepted Answer

Yes.  We produce tanks that can be placed up to a net 2 mtrs deep (from ground level to the top of the tank) and also carry direct overhead vehicle loads, class B and C. Ask us for our standard buried engineering if this arrangement is what you require.

You can also bury our standard tanks provided the loads to the sides and top of the tanks does not exceed the loads had the tanks been positioned as a retaining wall in accordance with Landscape Tanks™ standard engineering.  To be specific;
a)    The load capacity downwards cannot exceed weight equal to, the deep planter, soil and moisture and general plant mass which you could expect the planter to hold if it were sitting above ground.
b)    The sides of the tanks should not be placed in a position where the load from adjacent earth exceeds the standard engineering (including the “angle of repose”) that would occur in a retaining wall application.

Question 8

Can the tanks go under driveways?

Accepted Answer

Yes.  We produce tanks that can be placed directly under driveways and also carry class B or C, direct overhead vehicle loads.  We also sell complete packs of cut to length Bondeck®, steel bar and grates to allow your builder to quickly and with no waste cast the top / driveway with complete assurance.  Ask us for our standard buried under driveway engineering if this arrangement is what you require.

Question 9

Can I affix (posts etc) to the tanks?  Can I drill into the tank skin?

Accepted Answer

Yes.  Yes, but with the one exception, don’t piece the inner skin or do anything that would provide a channel for water to escape the tank or reach the reinforcing steel in the tank.  Anything you can do with concrete, you can do to the tanks, including affixing / fastening to the tanks.  Your approach to affixing to concrete, generally, should be used in affixing to your tank(s).  Our preference (and just our preference) is Trubolt® anchors (or equivalent) over DynaBolts™. For posts and high load bearing (for gates etc) our preference is the use of plates, to spread load.  In short, be conservative, do the job well.

In the event you damage your tank, for example, you chip or drill through the inner surface etc, fear not.You can repair your tank the same way you would repair concrete, with a resin or concrete repair kit.Follow the directions provided by the repair kit manufacturer.In the great majority of cases, after a short period, you will be able to re-drill and affix to the repaired portion of your tank.

Question 10

What happens if the earth works move / settle?

Accepted Answer

Nothing.  Small (normal settling) changes to the earth works under your tanks can be accommodated by the seals.  ‘Small normal’ meaning, millimetres difference between tanks.  Even though its outside our general tolerances, we have seen the seals accommodate differences between tanks of up to 25 millimetres and more.  We don’t recommend reliance on the seals to tolerate poor site preparation.

Question 11

How do the patented interconnecting seals work?

Accepted Answer

Cleverly.  Seriously clever but also in a seriously simple way.  They represent engineering which works and works well.  Think of two circles, a larger circle and a small circle inside that larger circle.  The inner small circle holds tight to the pvc connecting pipe.  The inner circle can move a little (millimeters) left and right, up and down and also accommodate changes to the angle of pvc pipe connected to the seal.  This is enough to allow the seal to accommodate slight and changing differences but remain water tight.  It’s important to understand that some seals (ours or others) bleed (less than a tea spoon a year and not noticeable, or a millilitre per day and appear like the seal is sweating).

Question 12

How quickly can the tanks be installed?

Accepted Answer

Quick.  The long answer is, the installation rate is mostly dependent on site based factors namely, terrain and accessibility, not the tanks.  They may weigh tonnes (2-3t to be exact), but what burns time is not the positioning and placement of the tanks, it’s the time taken to navigate trees, get around houses, the distance from the road, how steep the block is, whether the ground being traversed is firm or water logged etc.  Theoretically, on a perfect site, close to offload without any restrictions and with good safe and effective equipment operators and good preparation, we would expect a tank to be placed, as fast as, every 15-30 minutes. With average site access and conditions, we would expect approximately 10 tanks (including planters) to be placed per working day.

Question 13

What are the general manufacturing tolerances of our tanks?

Accepted Answer

2mm +/-  All concrete tanks are to a smaller or larger extent, handmade. Our tanks are cast from high quality, precision engineered, steel moulds. The concrete pour is layered and wackered (a proprietary system). A process that is repeated until the mould is full and we are confident about the compacting of the concrete mix (to get the best possible finish). Each mould is leveled prior to each pour. The seals are hand placed into the tank on sleeves which are magnetised and clamped at set positions (this statement assumes standard seal positioning). Cement shrinks by less than 1mm over the length of the moulds, as it cures. Given these manufacturing conditions, we expect minimal or no difference to our specifications for most tanks we cast. Even with the best care and operator competency, small variations between each tank and to the specifications, will occur. It’s impossible not to have slight variations. There is a limit to human sight, heat expands metal, leveling is limited by the human eye, concrete mix is heavy and can jar seals, manufacturing of seals produces small variations.

Question 14

What forces are the tanks designed to withstand?

Accepted Answer

External forces against the long side from retaining earth without the stabilisation of the weight and counter force of water in the tank.  The tanks are designed and built to A/S 3600/2001 and to be able to withstand loads inwards, outwards, downwards, continually and or periodically.  It’s not unusual for an engineer or builder to be surprised by the weight of our tanks.  The weigh reflects widths and the magnitude of materials used in construction.  We operating on the high not low side of inputs / materials, labour and mould precision. We sit at the opposite end to your lowest cost, don’t care about their look, (to be hidden or buried), tank manufacturer.

Question 15

Does drainage need to be installed?

Accepted Answer

Yes.  General good practice and all applicable codes apply to our tanks for each of the applications they perform.  In a retaining wall function you will need to comply with retaining wall drainage good practice, for example, perforated pipe with sock (geotex or similar), with crushed rock, a spoon drain at the top with fall etc.  What you would do for a block retaining wall (or any other format of retaining wall for that matter) you do with our tanks.  There are no additional requirements on account of you using our tanks in a retaining wall function.

Question 16

How does installation occur?

Accepted Answer

Quickly and easily, it has few technical components and requires only a relatively small amount of site preparedness.  Site preparation involves clearing a level platform of expose clean soil which can bear 100 kPa or more.  The platform cannot have rubbish or decaying matter; preferably it should be clear virgin soil.  Onto the soil you place 50mm of class 3 crushed rock or road base, screed it flat or with a slight fall and compact it to 100 kPa or more substrate firmness. You will need a level, string line and rake.  The tanks are usually offloaded with chains by lifting equipment (telehandler etc) and the four incorporated “pin head lifts” located diagonally in each corner of each planter and tank.  Survey and mark your starting point.  Lower the first tank into place and check its level.  Lift the tank and visually view the crushed rock for pin point high or large rough low points.  If either exist, correct by raking off or adding crushed rock, as applicable. Place the tank.  Put a string line on the first tank and collect the next tank and repeat the process.  Align the tanks using the string line.  Rake off or add crushed rock as applicable to get the tanks level and in-line with each other.  Prior to placing the planters, insert the PVC pipe provided into the equaliser and overflow seals.  Before inserting the pipe, ensure the seals are clear of debris and intact, lubricate (preferable not compulsory) the seal, insert the pipe and jiggle it so the seals are neutral (neither convex nor concave).  Rotate the planters so the orientation of the drain suits your site.  Plumb to roof, storm water and pump, when convenient.

Question 17

Do the tanks require footings, anti-slip, pinning or other supports?"

Accepted Answer

No.  Cut the earth to clean virgin soil, add a base of class 3 crushed rock, screed and compact it to level so that it offers (bears) 100 kPa or more substrate firmness.  No trenches, no stabilising, no reinforced concrete, no pinning and no anti-slip measures are required.  The tanks are designed (see the standard engineering) as stand-alone retaining walls and rain water tanks.  They are significant, stand-alone, concrete structures. If your circumstances require additional anti-slip measures, ask us for a referral to our consultant structural engineer partners. They have practical cheap ways to increase hold and reduce slip.

Question 18

Can I stack the tanks on top of one another?

Accepted Answer

Yes & No. Yes. If you wish to store the tanks onsite prior to installation you can stack the tanks and planters on top of each other.  For work place safety and efficient installation reasons, we don’t necessarily recommend storage and stacking of the tanks. If you do stack the tanks, rest the tank on two gluts, one either end.  We often stack manufactured tanks 4 high onsite but our site is hardstand and near level.

No. The wall strength and loadings are designed and calculated to occur (principally) from the outside in or inside out or both outside in and inside out and from the planter down, only.  The maximum load from the top down is limited to the planter weight, dirt, water and assumed plant mass, with a margin. They aren’t designed to take the weight of a 4 tonne plus tank, planter and soil, water and plant mass.

Question 19

Are engineered retaining wall computations available?

Accepted Answer

No.  We provide a general engineering retaining wall schedule which includes earth back filling levels and the “angle of repose” details for our three tanks for the standard and deep planter tops.  Six sets of detail.  It will satisfy most customer requirements.  We aren’t engineers, we don’t do site inspections and we aren’t installers.  Get an expert (builder, landscaper, plumber etc) or whoever you plan to contract to perform your project to install the tanks, based on your specific requirements, to check our engineering schedules appropriateness for your circumstances. They will be able to advise you as to whether you require additional professional engineering performed.

FAQ

Some of our frequently asked questions