dry - LJN Blog Posts - Landscape Juice Network2024-03-28T10:00:43Zhttps://landscapejuicenetwork.com/profiles/blogs/feed/tag/dryHow are Britain's gardeners coping with a hot summer?https://landscapejuicenetwork.com/profiles/blogs/how-are-britain-s-gardeners-coping-with-a-hot-summer2013-08-08T07:21:44.000Z2013-08-08T07:21:44.000ZLandscape Juicehttps://landscapejuicenetwork.com/profil/LandscapeJuice<div><p>The Telegraph talks to head gardeners around the country and get their tips and tricks for looking after gardens when temperatures are high:</p>
<p><a href="http://www.telegraph.co.uk/gardening/gardeningadvice/10229098/How-are-Britains-top-gardeners-coping-with-a-hot-summer.html">http://www.telegraph.co.uk/gardening/gardeningadvice/10229098/How-are-Britains-top-gardeners-coping-with-a-hot-summer.html</a></p>
</div>Dry Stone Walling Cornwall. An engineering solution for bank stabilisation & drainage.https://landscapejuicenetwork.com/profiles/blogs/dry-stone-walling-cornwall-an2010-04-07T20:30:00.000Z2010-04-07T20:30:00.000ZSustainable Land Managementhttps://landscapejuicenetwork.com/profil/SustainableLandManagement<div>Dry Stone walling in Cornwall is enjoying a renaissance at the moment. Principally due to the costs compared with alternatives. An additional factor is that as the actual mechanics of these historic structures are being researched properly, (mainly due to Engineers in <a rel="nofollow" href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V2Y-4MKTXVY-1&_user=10&_coverDate=09%2F30%2F2007&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1228116965&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=6307440fa29a3a9cb8026b99a017fa16" target="_blank">North America</a> recognising the attributes of the walls), and subsequently walling is being re introduced into an engineering schemes as the preferred method of mitigation.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314084085?profile=original" alt=""/></p>The completed wall above looking out over the Carrick RoadsThe 'Cornish Stone Hedge / Wall' is recognised <a rel="nofollow" href="http://www.pierreseche.com/" target="_blank">internationally</a> and does differ considerably from other forms of dry stone wall in the UK. This is due principally to the slate formation stone used.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314145772?profile=original" alt=""/></p>This 12 tonne pile is ex <a rel="nofollow" href="http://www.csbt.org.uk/publish/docs/documents/CornishBuildingStoneandSlateGuide2007.pdf" target="_blank">Tredinnick</a>, (<a rel="nofollow" href="http://www.btinternet.com/~mattpower/Fal/Main/geol.htm" target="_blank">Trevose Slate Formation</a>) and at £250 / per load is one the cheapest available in Cornwall. It is also the nearest match to the slate formation bed rock found in the region of the discussed project below.A steep bank shelving immediately off from a slightly downward sloped garden. A few years previously storm water run off caused a large part of the garden to slip onto the shoreline, (In the area of this photo - the edge of the turf is where the proposed wall is to be constructed)<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314148707?profile=original" alt=""/></p>The resulting backfill had to be held using <a rel="nofollow" href="http://www.hy-tengabions.com/rock_netting.htm" target="_blank">rock netting</a> with gabion blocks on the upper level part of the garden. Such engineering whilst practical and useful is difficult to work off in terms of boundary construction, (including fencing and hedging). Also drainage is a serious issue. whilst storm drainage systems have been implemented for road surface water run off significant amounts of water still need to be able to drain through the area between the rocknetting and whatever is constructed.A dry stone wall acts as a drainage unit in its own right. Digging shallow foundations onto the top of the netting with backfill of loose stone enables a channel which feeds to the quoin at the lowest end of the wall.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314147343?profile=original" alt=""/></p>The layer above the loose stone backfill, just above the surface, requires heavy stone, which interlocks with both faces. This keeps weight onto the smaller foundation stone. Above this the stone wall is constructed with a mix of predominantly smaller stone, but with some soil backfill. The walls are constructed at an angle of 85 degrees, just enough to ensure a downward thrust of weight directly onto the base.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314144653?profile=original" alt=""/></p>This particular wall differs in so far that the capping will be of dry stone also - without an allowance for planting.As the wall bends in to hit the slope, it is absolutely essential to maintain a horizontal plane at the base. The stone allows for some change in pattern, (not wished for here), in so far as introducing bee boles or verticals.Metal pegs together with a small concrete plug, (9 in total - 2 bags of mastercrete), allow for the base of the wall to fit onto the sloping rocknetting. A straining point is also built as a 'belts and braces' measure between the lower level stretch and the climb up the hill.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314148539?profile=original" alt=""/></p>The resulting finish will be preferential to neighbours / <a rel="nofollow" href="http://www.cornwall.gov.uk/default.aspx?page=2449" target="_blank">local authority</a> and the of course the owner and will assist in preventing build up of pressure points by water, as well as weighting down the rock netting at a downward angle reducing risk of further erosion.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314146263?profile=original" alt=""/></p><p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314147761?profile=original" alt=""/></p><p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314144376?profile=original" alt=""/></p>Finished wall 48 metres at a cost of £4800.00<a rel="nofollow" href="http://www.cornishgardenlandscaping.co.uk" target="_blank">www.cornishgardenlandscaping.co.uk</a><a rel="nofollow" href="http://www.facebook.com/pages/Cornish-Stone-Walls-Hedges/175511807867" target="_blank"><b>Cornish Stone Walls</b></a><b><a rel="nofollow" href="http://www.paysagedurable.com/" target="_blank">www.paysagedurable.com</a></b></div>Traditional Quay Construction in South West UK - Part II.https://landscapejuicenetwork.com/profiles/blogs/traditional-quay-construction2009-12-29T21:00:00.000Z2009-12-29T21:00:00.000ZSustainable Land Managementhttps://landscapejuicenetwork.com/profil/SustainableLandManagement<div>Further to last Quay construction <a rel="nofollow" href="http://www.landscapejuicenetwork.com/profiles/blogs/quay-construction-traditional">blog</a> this is the second quay.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314150328?profile=original" alt=""/></p>In this one we had to construct from base as there was no existing material to use. Stone was from Tredinnick Quarry and a total of 30 tonnes was used.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314144434?profile=original" alt=""/></p>The above photo shows the walkway which was able to be constructed with horizontal layering as the rest of structure protected it well. Evidence of Otter activity in the locality led to the inclusion of a false 'holt' made inside the structure.Also built was a duck tunnel onto the area between the neighbouring properties.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314149119?profile=original" alt=""/></p><a rel="nofollow" href="http://www.paysagedurable.com/" target="_blank">www.paysagedurable.com</a></div>Insurance Companies and the landscaping Industryhttps://landscapejuicenetwork.com/profiles/blogs/insurance-companies-and-the2009-12-05T14:30:00.000Z2009-12-05T14:30:00.000ZSustainable Land Managementhttps://landscapejuicenetwork.com/profil/SustainableLandManagement<div>As traditional landscaping techniques creep into suburban areas or more often suruban areas creep into ex agricultural areas with elements of traditional landscaping maintained as features as prescribed by planning authorities and quite rightly. There is an increasing problem with the insurance implications. The following is an example of such a problem:Further from the <a rel="nofollow" href="http://www.landscapejuicenetwork.com/profiles/blogs/retaining-stone-walls-in">retaining wall</a> failure blog, the recent spell of enquiries with regards remedial operations to older and some newer structures has also highlighted another more significant problem with traditional and sustainable landscaping practice.November's rainfall resulted in 12 enquiries to ourselves with regards wall collapse all but one were dry stone structures. (It is important to note that there were a huge amount of mortared and block walls which collapsed in this period, but this is not our field.)Of the 11 remaining walls, 7 of the householders concerned went to their insurance companies - 4 of the insurance companies were happy to pay, following a visit from an assessor. 2 of the walls the remedial operations were small enough to almost match the excess and as such the insurance was not needed.The final wall, which was initially a very well made structure, albeit smothered with Ivy was part retaining, (800mm),<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314140290?profile=original" alt=""/></p>but largely a free standing structure, built from metamorphic stone, which although related to the slate formations of Cornwall is substantially stronger and is more often located in the more post industrial areas of the county. (This wall is found within 3 km of the heartland of the tin mining zone). Built in the late 19th to early 20th century it was a serious piece of workmanship. The retaining element is all important here, as the garden level has probably risen considerably during this period. As such it soaked up much of the heavy rainfall, with little drainage. Consequently near the roots of the magnolia the stone was weakened in an already susceptible place and as surface water flooded through the expanding gap it allowed the horizontal plane stones to effectively 'float' out of position. The photo clearly shows the result and the reality that the wall is at real risk of further collapse. The wall is in a poor state in general and as such several factors can be attributed to the collapse. Subsequently the assesor was able to list a few factors; it only takes one possible factor for the claim to be dismissed.The point of the above example is twofold:Firstly during liaison with both the assesors involved both stated that they didn't really know about such walls. This isn't surprising as the geotechnical data is scant and any resulting guidelines filtered down to practitioners is very basic. After all with most land based traditional techniques the <a rel="nofollow" href="http://handbooks.btcv.org.uk/handbooks/index" target="_blank">BTCV handbo</a>oks have remained the standard for the past 20 years, I am not critisicing these handbooks, which are excellent, but it is just meant to be a simple guide and not representative of the huge variety of styles resulting from differing techniques honed across the diverse geography of the UK and certainly not intended as a guide for the actual craftsman and woman who have the specialised regional skills. The problem therefore for the practitioners and the insurance companies is where to go for the specialist knowledge needed in determining such cases.Secondly as most of the problems related to mechanical failure in traditional landscaping skills will be the result of weather, how is it going to be possible to ensure that adequate measures are adopted into gardens in order to allow the remnants of traditional techniques to survive. At present SUDS regulations and other attempts to alleviate environmental problems rarely take account of the existing traditional structures which co exist with the concrete boom following WWII. Therefore it is paramount for new regulations to take account of this loophole.In the above it is not necessary to criticise the insurance companies, but I know of and I am sure many others have come across examples where the insurance companies have acted not out of forgiveable ignorance but actually using the highlighted problems as a means to wriggle out of paying. Bearing in mind the current potential costs to insurance companies we may see an upward trend of such decisions.Without naming any of the insurance companies who have unjustly refused payment I will state that the <a rel="nofollow" href="http://www.nfumutual.co.uk/" target="_blank">NFU</a> who have an agricultural history have as far as I have seen persistently understood these traditional techniques and have been able to identfiy and insure accordingly for potential problems.<a rel="nofollow" href="http://www.facebook.com/posted.php?id=175511807867" target="_blank">Cornish Stone Walls and Hedges</a><a rel="nofollow" href="http://www.paysagedurable.com" target="_blank">www.paysagedurable.com</a></div>Retaining Stone Walls in Cornwall - Failure in Older Structureshttps://landscapejuicenetwork.com/profiles/blogs/retaining-stone-walls-in2009-11-18T19:30:00.000Z2009-11-18T19:30:00.000ZSustainable Land Managementhttps://landscapejuicenetwork.com/profil/SustainableLandManagement<div>Following the recent adverse weather some older Cornish retaining walls have collapsed and there have been several enquiries relating to this, there have also been some real problems for clients with regards dealing with the insurance companies. Assessors tend to have a knowledge only within the construction industry which consequently leads to confusion and then often refusal of payment, this subsequently leads to the loss of a historical and traditional feature of the region. However often the cost of minor repairs can be less than the excess involved and certainly cheaper than other forms of retention, which may be chosen in the misguided believe that it will be cheaper than the dry stone work.The following may assist in determining some of the major problems associated with the walls. It is a heavily abridged version of some work by Jamie Flattery, prior to his leaving to live and work in Canada.Mechanical Failure in Cornish Dry Stone Retaining Structures:As the use of Dry Stone, principally slate formation or granitic stone, comes from ancient traditional techniques much of the engineering principles and standards have been acquired through the dissection of ancient structures. Structures built using slate formation are considerably younger than granitic structures and tend to be concentrated in coastal sites on the North Cornish Coast. However there is evidence of some ancient slate formation walls constructed using a horizontal pattern, similar to the Cornish Hedgerow standards of today, in the Falmouth area. These walls have seemingly bonded together due to weathering to create near vertical structures, which have survived due to a solidification of the back material also and run off flowing over the top.Dry stone structures in the main, fall under the remits of soil mechanics in engineering terms rather than standard structural engineering principles, although in the US it has been widely used as a standard system for seperate level boundary structures and for sub urban landscape engineering. The principal academic research comes from edaphology studies as the combination of the vegetation within the structure is a significant element of it’s longevity.Such research is somewhat lacking in availability and these walls when constructed within engineering principles are now principally sought as a means to create a faced drainage system. However the majority of all walls now built are due to aesthitic choice and more recently for cost savings due to the increases in the cost of pre fabricated or cement based products, many of which in turn were borne out of the need for such products after WWII, when there was a shortage in the natural stones due to a combined shortage of suitable mechanical quarrying equipment and labourers.Failure tends to occur soon after construction, which can be easily remedied, or after a significant change in the surrounding soil make up; which can occur anytime in a period of between 70 and 350 years after initial construction. The changing soil profile due to natural processes can lead to dramatic failure, often occuring after heavy periods of rainfall as the changed soil profile blocks the natural drainage available in the structure.Alternative intervention to walls leads to the same problem:Walls which have been removed of their vegetation or have been pointed or repaired using mortar are highly susceptible to damage.The overlaying of impermeable surfacing in front and at the base of the structure leads to a deepening of the foundations of these structures, which are often built in shallow footings. The foundations are built to a depth which allows for the displacing of both groundwater seepage and surface water runoff over a suitable soil profile. In Cornwall this layer is often shallow, (commonly found between 400 and 600mm depth) and is generally the surface of a compressed sub soil clayey shale and shillet layer, which lies undisturbed and is significantly less permeable.Modern construction practices have often been practised with an ignorance for the correct soil profile to be reinstated after operations to the building, which usually only see surface remediation by way of re laying a top soil over the disturbed soil. This can often lead to a weak profile within the soil which is easily disturbed in adverse weather leading to poor drainage, (this is often all too evident in the planting of such gardens and is a common landscape engineers gripe) and sometimes serious mechanical failure of existing dry stone structures within <200m of the new build.By far the most common failure in older structures is alterations in the groundwater seepage, following significant rainfall. The soil profile is continually changing and clay particles will accumulate on the inside of the wall structure building up to levels which block the drainage through the wall, thus leading to serious mechanical failure by way of pressure build up.Dr J Flattery Phd, MSc.<a rel="nofollow" href="http://www.facebook.com/pages/Cornish-Stone-Walls-Hedges/175511807867" target="_blank">Cornish Stone Walls</a></div>Quay Construction. Traditional quay build with dry stone in Cornwallhttps://landscapejuicenetwork.com/profiles/blogs/quay-construction-traditional2009-08-14T19:00:00.000Z2009-08-14T19:00:00.000ZSustainable Land Managementhttps://landscapejuicenetwork.com/profil/SustainableLandManagement<div><p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314130765?profile=original" alt="" width="314" height="235"/></p>We are currently in the middle of two adjacent contracts constructing quays on the edge of the Fal estuary in Cornwall. When we first quoted and tried to gather as much information about quay construction as possible it was difficult to discover much at all. The BS information is based largely on more modern standard construction and concentrates predominantly on the waterproofing qualities of the materials. Using drystone negates much of this and yet has been largely superceeded nowadays despite being very well suited to both marine and riparian constructions.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314124842?profile=original" alt="" width="235" height="290"/></p>Using large stones >25kg, (it is necessary that every single stone is of sufficient weight), each stone is selected for an even weight along its length which is placed to allow a narrow face. The stones need to be placed vertically as much as possible, (an uneven pattern can also work), this is due to horizontal stones effectively being able to float on a strong current. The back fill is loose and with an amount of gaps the water can simply flow in and out of the whole base of structure.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314129799?profile=original" alt="" width="314" height="235"/></p>Estuarine locations are by far the easiest locations in which to construct on the foreshore. The full force of the sea is usually tempered and flooding is not constricted and as such not fast flowing. Despite this it is essential to ensure the face is able to withstand very strong forces indeed. However the back of the wall face is under a much greater pressure - on high tides, particularly spring tides, the whole of quay becomes waterlogged and the pressure downwards and onto the rear of the facing stone is immense as the tide falls.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314132642?profile=original" alt="" width="314" height="235"/></p>The work is incredibly labour intensive, although the localities make up for the hard work. The photos are of the first quay in construction, 46 metres long, which is in an <a rel="nofollow" href="http://www.cornwall-aonb.gov.uk/" target="_blank">AONB</a> and surrounded by <a rel="nofollow" href="http://www.nationaltrust.org.uk/main/w-index.htm" target="_blank">National Trust</a> land; as such the design has to be traditional and the final finish needs to look in tune with the much older quays in the vicinty. A random pattern to the face allows for this easily.BEFORE:<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314131467?profile=original" alt="" width="314" height="235"/></p>AFTER:<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314137326?profile=original" alt="" width="314" height="176"/></p>The total cost for the above job came in below £5000.00, and as such it would be impossible to build a timber or concrete construction for the same price. Dry stone is becoming increasingly more fashionable as the prices for the stone become increasingly more competitive against prefabricated products. The sustainability factor cannot be beaten either, the stone for the above came from less than 20 miles away and all other materials were recycled.What is very amusing is to see the different species which utilise the quays in comparison to the dry stone walls.Crabs vs Toads. The final touch is a specialist seed mix for estuarine riparian and coastal headland, with strong rapid establishing grass seeds it is a mix that hardly suits any other type of lawn but will assist greatly in erosion preventative vegetative measures and <a rel="nofollow" href="http://www.remediation.co.uk" target="_blank">remediation</a>, (EPV) thus ensuring the longevity of the structure.<p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314130517?profile=original" alt="" width="314" height="176"/></p><p style="text-align: left;"><img src="http://storage.ning.com/topology/rest/1.0/file/get/3314136994?profile=original" alt="" width="640" height="480"/></p><a rel="nofollow" href="http://www.facebook.com/pages/Cornish-Stone-Walls-Hedges/175511807867" target="_blank">Dry Stone walls in Cornwall</a><a rel="nofollow" href="http://www.paysagedurable.com" target="_blank">www.paysagedurable.com</a></div>Cornish Stone Walls - Pure Sustainability.https://landscapejuicenetwork.com/profiles/blogs/cornish-stone-walls-pure2009-03-19T22:30:00.000Z2009-03-19T22:30:00.000ZSustainable Land Managementhttps://landscapejuicenetwork.com/profil/SustainableLandManagement<div><p>Following the recent forum post and given the increasing demand from both private and commerical clients, (the latter as a result of the UK's ratification of the EC Landscape Convention). It is worth gathering information on the history and proper methodology of building these structures, which is relatively scant to the say the least. Certainly it is evident that both in Devon and Cornwall many of the walls which have been built recently, particularly the large scale, roadside and new housing estate structures, fail to meet the traditional and sustainable elements which make these structures so unique internationally. this is not the fault of the landscapers building the walls but a mammoth failure to understand the true heritage of these structures.<br/> <br/> The structures are known to date back to neolithic periods. The reason was simple, using the stone, (or in many parts of Devon, where due to the geography and geology loose stones were rare and turf was used instead), which were spread across the landscape to create a boundary to enclose livestock. The walls over the years became more solid, additional smaller stone and waste material was added to create a core thus enabling higher walls. This meant that larger livestock could be farmed together with providing shelter or windbreaks for crops by minimilising the need for larger trees to be planted. And these walls were completely unique to particular areas, (up to only 30 years ago it was possible to drive around and discover not only the direct geology of an area, but also a good guess of the depth of top soil by simply looking at the hedges), differing dramatically in style in less than a kilometre. An example of this can be found easily on the North Coast of Cornwall, much smaller stones closer to the sea are freely available as such herringbone and vertical patterns were easily achieved. The very loose backfill material allowed for steeper sides also. Yet only 5 miles inland the rock changes to a different slate formation, much larger stones are then used and as such it is simpler to built the wall in the horizontal pattern. One area well worth seeing is the Mylor Bridge area, here many of the walls are constructed from the underlying quartz, which creates walls which when seen close up can sometimes reflect rainbow colours. The trees and growth on the walls was also distinctly different - as with native tree mixes in our ancient woodlands the mix of species on the walls changed dramatically.<br/><br/>Stiles had always been incorporated, but bee boles, milk urn shelves and underpasses started to be introduced more and more. Wildlife populations in these structures was high and the hedgerows started to act as motorways for wildlife. The list of species found in these hedges is almost as long as a list of UK fauna & flora.<br/><br/>There is considerable evidence that until recent history these walls were mainly built by women, and following the enclosure act, the landowners started to demand much more elaborate walls, which would illustrate their influence. As such many new walls were built in square cut granite and other intensive or imported materials - the death of the sustainable hedgerow started.<br/><br/>Now as you drive down the A30 there are miles and miles of uniformed 'Cornish hedge', built to a relatively new standard introduced, (even the tree mixes now recommended varies little throughout SW England). This is more attractive than fencing, one has to admit - but it takes no account of the differing areas of Devon and Cornwall, the varying heritage and most importantly is built using imported top soil, which is simply an extreme overkill and not good for the longevity of the hedge. Paradoxically the material removed for the necessary ditch operations is used elsewhere. As such the Cornish and Devonian Hedgerows are no longer the beautiful and unique feature they once were and its only the small scale stonewallers and the more insightful clients who are maintaining or constructing new walls in the traditional manner - stone from the local quarry or even from onsite - hedging mixes matching the ancient hedgrow species and styles incorporating from the outset habitats for beneficial wildlife species, but this is minimal against the destruction of these structures which has occured throughout the 20th century.<br/><br/><a rel="nofollow" target="_blank" href="http://www.facebook.com/pages/Cornish-Stone-Walls-Hedges/175511807867"></a></p><p><a rel="nofollow" target="_blank" href="http://www.cornishgardenlandscaping.co.uk/6.html">Cornish Garden Landscaping</a></p><p> </p><p><a rel="nofollow" target="_blank" href="http://www.facebook.com/pages/Cornish-Stone-Walls-Hedges/175511807867">Cornish Stone Walls</a><br/> <br/> <a rel="nofollow" target="_blank" href="http://twitter.com/cornishwalls">Stone Walling in Cornwall</a><br/><br/></p></div>