STANDARDS

[Deiniolen]
Good quality stone work should last 100-150 years with a minimum of maintenance. Failure of works within 5 years is frequent, often the result of cheap tendering and a subsequent emphasis on speed rather than quality.
The difference between good and bad work in walling is possibly greater than any other skill. Assessing the quality of workmanship can be problematic even for those with an experienced eye, with much of the strength of a wall being hidden in its innards. The following is a brief guide to some of the basic factors of good craftsmanship. Further information is found in the technical appendix of a report I compiled for Gwynedd Council Environment Directorate acting as Department's Representative for the Welsh Assembly Government Transport Directorate. It covers the most common aspects of poor workmanship, with plenty of photos. It is included on this site click here to view.

INDEX

Standards

QUALITY

With stone work, just as with most things that cost money, you normally only get what you pay for. This is not to say that a high price necessarily means quality work, but it does normally mean that cheap prices mean work of a lower quality.

Judging quality in a wall can be difficult. It is often possible to make stonework look good without the end result being particularly structurally sound. However, a good craftsman should be able to produce work that has both a good finish and is strongly built.

So what is quality? Most of the principles in dry stone work can be equally applied to other forms of stone work, so it is applicable to identify the key aspects of a well built dry stone wall.

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Foundations

photo when I find it!

Should be laid in a levelled trench, butting up tightly to their neighbours, an even width along the length of the wall/repair, with any extra large stones used now rather than later. A key aspect is the placing of stones with their longest axis pointing into the wall: not "traced" -that is with the length of the stone run along the wall - stones placed in this way are more likely to become displaced. 'Tracing" is a frequent fault in cheaper work as it is faster and easier. The stones complete more of the length of the foundations so less stones have to be placed, and it is easier than trying to fit them lengthways into the wall where stones on the opposite side of the wall with have to be painstakingly fitted around them.

Many collapses of old walls are the result of uneven settlement of the foundation, yet all too frequently the original foundations are not removed as this is usually the single most time consuming aspect of rebuilding. The result is that the problem is merely covered up rather than rectified.

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Building Stones

The building of the actual wall should also follow these principles particularly the absence of "tracing". It should be noted that with some stone types, such as slate, some tracing is unavoidable, in these cases traced stones should not be placed next to each other; either along the wall, or on opposite sides of the wall. Similarly one stone should not be traced on top of another.. With these types of stone it should normally be possible to compensate with an increased number of through-stones (below).
[TightFits]

Tightness, that is an absence of gaps between stones, is also important. It reduces the chance of collapse by limiting the potential for stones to move during settlement.

Another consideration is the bridging of cracks, with one stone sitting on two and two on one

- just as in a brick wall. "Running joints" of more than 2 stones are a serious weakness and show a lack of care in construction. Running joints of just two stones will be virtually absent in a well constructed wall.

Much of the strength of a wall is internal and not visible from the outside. With most stone types it is possible for much of the building stone to be placed in such a way that the stones interlock within the wall. The fewer the gaps in the heart of the wall, the stronger the wall. A good craftsman achieves this in addition to a tight and neat face, with all aspects going hand in hand.

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Hearting

One of the major faults in a poor quality wall is the lack of "hearting" or packing within the wall. The hearting should be thoroughly packed in, not thrown or shovelled in, and placed in a way that minimises gaps or voids. This can be one of the more time consuming aspects of wall construction, but it is easily skimped on as it cannot be seen from the outside. Its importance should not be underestimated: as the wall settles the hearting prevents the total collapse of the wall reducing the movement of the face stones and preventing wedges from falling into voids et cetera.

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Line and Batter

Another important consideration is the line and "batter" (slope of the face). These are not merely meant to make the wall look good, they add to the wall's durability and, in stock proofing terms, its effectiveness. The "A" shape of a wall adds to its structural strength; the more vertical a face the more likely the wall is to topple during settlement. Bulges in the face mean that it will take less for the wall to fall down as some of the stones are already effectively part way out of the wall. Irregularities in the line and batter also dramatically increase the likelihood of stock, especially Welsh mountain sheep, being able to get over the wall. Unfortunately a good line and batter are often achieved by "tracing" stones and/or by using stones which do not butt up to their neighbours. Any competent craftsman should be able to combine good structure with a good finish, with improvement in achieving both aspects normally going hand in hand as the craftsman's skill develops.

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Through-stones

[Throughs]

These are stones which completely traverse the width of a wall serving to help bind the two faces together and thus reduce the chance of the wall bulging - another feature of a wall's structure which cannot be seen from the outside. These should be placed at regular intervals throughout the length of a wall (usually about every metre). Through-stones are not always present in North Walian walls. Where this is the case care should be taken to ensure that pairs of 3/4 "throughs" are regularly used, and care needs to be taken in their selection and placement.

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Coping

These are the wall's top stones. The most visible and easily assessed aspect of work, yet frequently very poorly done. Whilst the original stones might have gone it is normally possible to find sufficient replacement from within the wall. Where they are present they

need to be carefully sorted from amongst collapsed stone, or taken from the original coping stones with replenishments selected from within the wall to replace damaged and smaller stones. This can be time consuming, and selection of larger stones from within the wall can then slow the actual building process as smaller stone is used in the reconstruction. A poorly coped wall is of little use: if the coping stones become displaced there is nothing holding the top of the two faces of the wall together, stones inevitably come off the wall (stock accelerate the process).

Stones should not be simply piled on top of the wall. Each stone should sit solidly on its own base and fit tightly, with wedges forced into any gaps to provide a tight, locked finish. Whilst it would be possible to dislodge any coping stone with sufficient force, none of the stones on a recently repaired section of wall should move under reasonable force. The end result should also be a regular, relatively level top, not only because it looks good, but because it reduces the chance of stock trying to jump over the wall.

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Cloddiau

The earth core of stone faced earth banks or "cloddiau" makes them inherently unstable. Consequently considerable care needs to be taken with their construction, applying all the principles of dry stone work, coupled with careful compacting of the wall's core - the first thing to be skimped upon when prices are low.

There is a tendency for all gaps in the face to be stuffed with pieces of turf, to produce an instant aged look, or to cover up deficiencies in structural technique. Evidence and common sense suggest that the traditional cloddiau were built without this turf, the stone is often very well placed to give a tight face and turf has only grown over many decades. Where too much turf is used there is a high risk that it will shrink as it dries out leading to a collapse of the wall, especially where stone is bedded on it. It is important to maintain stone to stone contact.

Another consideration with cloddiau is the local style. With cloddiau the style is apparently very much determined by the local stone type, but the majority of them are constructed out of stones laid in courses and set vertically whereas the dry stone walls of North Wales are predominantly built with random rather than coursed faces. it is good practice to check other cloddiau in the locality before deciding on the appropriate pattern.

The 'vertical coursed' pattern is an important regional style that is often neglected and there seems to be a misconception as to their stability. Where the stones are well placed the end result should be similar to the wail being built out of several layers of very tightly fitting coping. Correct construction technique should produce stones which are effectively wedged together in a way that is far more difficult to achieve than with random work, thus negating much of the in-built instability caused by the earth core.

Clawdd walling lends itself more to the use of machinery, such as mechanical diggers, than other types of stonework primarily because of the amount of excavation involved, the use of these diggers in dismantling walls can be a mistake as soil and stone get mixed and unless considerable care is taken to re-sort the stone a poor or inappropriate wall often results. Special care needs to be taken when filling the centre of a clawdd by machine as the tendency is to overfill making adequate compacting of the fill impossible.

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Retaining Walls

These are single sided walls which support earth banks and can be dry stone or mortared. Considerable care needs to be taken to, ensure a particularly strong structure in order to support the bank "Traced" stones represent a serious weakness in this type of wall. Considerable care needs to be taken with filling behind the wall and compacting this soil -similar to cloddiau.

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Wet Stone Walls

With most, but not all, stone types the principles for dry-stone work apply equally with wet stone work, although the potential for short cuts is greater as bigger liberties can be taken. With wet stone work it is often possible, although not necessarily structurally sound, to set stones vertically with their largest surface in the face of the wall. With blocky stone this is often the accepted practice.

A key to good wet stone work is an even spread of mortar between the stones. With rounded rock types this can be difficult to achieve and allowances have to be made. However there should not be any overly large masses of mortar and it should still be possible to set stones to a true level rather than at all sorts of angles.

Particular care needs to be taken with wet stone work if discolouration of the face stones through contact with mortar is to be avoided.

All the gaps between stones should be raked out before the mortar sets and subsequently pointed.

An often neglected variation on wet stone walling is to build a wall with a dry stone face but mortared centre. the mortar taking the place of hearting and wedges.

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Finish

Quality is not about looks. A good piece of wall combines the factors of constructional strength with neatness of finish. Craftsmanship involves the marriage of these two factors to produce an end result that is both neat and strong. You can have one without the other, you should have both. It is important to remember that a good craftsman is not charging more simply because the end result is neater and arguably looks better, but primarily because the whole wall has been built better and as a result also looks neater than a poorly built wall.

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COST

A simple response to how much does it cost to repair a wall is "how long is a piece of string". As much of the strength of a wall is internal you are very much at the mercy of the contractor when it comes to the quality of the work being produced, you will frequently only get what you pay for. As the possible shortcuts are numerous in such a technical craft, speed frequently results in a drop in quality.

You can pay almost anything: an average for reasonable work might be around £20 to £30 per square metre for dry stone work, but anything from around £16 to £40 per square metre might be applicable, especially if you want a wall that is going to last.

Not everyone charges per square metre, some charge per linear metre, others a lump sum -the latter is the most risky.

With lump sums you are more at the mercy of the contractor than other forms of payment. The price will be high enough to allow for problems and if the job goes according to schedule you could probably have got a better job done for less on a square metre rate. If the job is not going according to schedule then corners will almost inevitably be cut in order to speed the work up.

Similar problems can arise with "piece rates", especially at the lower end of the price scale. There is greater likelihood of the contractor having to "throw the wall up", rushing and cutting corners, if the price is too low.

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Pricing General

No two wallers are going to see the same piece of wall in exactly the same light, nor approach pricing in the same manner. Distance from home might (but not always) affect the price. Distance from vehicular access can also increase cost, as can the terrain - especially boggy or sloping ground.

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Stone

Stone is an important consideration in pricing. Walls built out of small stone generally take longer to rebuild than walls built out of larger stone. Walls with a number of particularly large stones present other problems and can be particularly time consuming to rebuild. This is especially the case where the foundation stones are large boulders. Similarly, some types of stone (particularly angular ones) can be difficult to work with and thus increase the price. if stone has to be brought in then not surprisingly the price is likely to be higher. Often the client can save money by moving the stone themselves from elsewhere on the site, or by having stone delivered to the site. Do not assume that this is going to lead to the actual rebuilding of the wall being cheaper than if the contractor has to dismantle the original one. During the dismantling process the stone is sorted in order to enable faster reconstruction and good quality work, with stone roughly sorted into size and sometimes shape, awkward stones are also noted. Being confronted with a pile of stone (and this can apply equally to pieces of wall which have completely collapsed) can lead to increases in price as the stone will need to be sorted in order to produce a good job, if it is not sorted then the work will be slower (unless the wall is "thrown" up) and awkward stones left out or not used correctly.

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Height

Height can affect the price, especially where awkward foundations are involved. In a low wall the foundations represent a higher proportion of the work, and so a low wall might not cost less per linear metre than a slightly higher wall built out of easier stone. As the height of the wall increases so does the time in building it, unfortunately the increase in time is not necessarily proportional. it is often said that a metre length of wall 1.5 metres high takes almost twice as long to build as a 1 metre length of wall 1 metre high - depending of course on all the other factors involved!

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Retaining Walls

As a rule pricing here will be similar to free standing walls. Whilst the stone face tends to be a single thickness overall building time is rarely reduced as considerable time is involved in excavating banks, ensuring a particularly strong structure in order to support the bank, and filling behind the wall and compacting this soil.

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Cloddiau

Costing cloddiau is subject to all the criteria as for dry stone walls. Theoretically it should be more expensive given the need for excavating soil and ensuring adequate compacting of the centre. Cheaper work is often at the cost of adequate compacting of the centre.

Where the original earth bank is in good condition this should be left undisturbed and if this is the case it can be cheaper than dry stone walling. Large scale work also lends itself more to the use of machinery and can work out cheaper even allowing for the cost of the machinery.

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Wet Stone Work

Where the wall is not built dry and mortar is used between the face stones, as hearting, or both, it almost inevitably costs more, primarily because of the materials involved. Even if the client provides the materials the cost is likely to be more because of the labour involved in mixing the concrete and pointing the wall.

If the contractor is providing materials expect a wall with a dry face and a mortar core to cost around twice that of a dry stone wall, where a pointed mortar wall is required expect to pay around three times that of a dry stone wall - including materials.

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COST EFFECTIVENESS

It is not possible to give a definitive answer as to wall costs. Hopefully it is obvious that pricing is not as straight forward as at first appears and that cost cutting is fairly easy - at the cost of quality and longevity. The only thing that is certain is that if you pay a very low price you are likely to get a poor job, unfortunately higher prices do not always guarantee good work.

So why pay such high prices? We would all like to see all of North Wales' walls repaired, the economic reality is that this is not likely to happen. Yet walling is not necessarily as expensive as it would at first seem.

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Grant Aid

Many wall repairs are eligible for grant aid. The level of grant available is no simple matter. A number of different schemes exist in different areas, from a variety of organisations/sources, and are either percentage grants or fixed rate grants paying a set sum per metre. In the following examples we look at a number of possible grants in percentage terms. It is important to remember that lump sum grants are only meant to represent a contribution to the cost of the work and not to meet the entire cost, they normally represent something in the region of 50-80%.

If we have a wall l00m. long which is 1.3m high (the minimum to be regarded as stock proof) requiring a complete rebuild (130m2) then the following applies.

Effective cost with grants of:

price per m20%30%50%70%
18234016381170702
20260018201300780
22286020021430858
25325022751625975

£18/m2 is chosen as a starting point as the risk of poor quality work at prices below this level are particularly high, with £25/m2 a general benchmark for work of a reasonable standard, bearing in mind that just because someone charges craftsman rates it does not necessarily mean they produce craftsman`s work. The most widespread grant scheme in Wales is Tir Gofal a `whole farm` scheme which pays 18/m2 which is around 70% of 25 (actual = 72%).

It can be seen from these figures that the subsidised price is relatively unaffected, in terms of overall outlay by the owner, as the rate per metre rises, especially at higher grant levels. So better quality work is not necessarily that much more expensive. It is also as well to consider that with good craftsman the increase in quality and longevity of work is proportionately higher than any increase in price resulting from this craftsmanship.

This still represents a considerable outlay, however where the boundary needs stock-proofing this is of direct benefit, and the cost of grant aided walls can compare favourably to that of fencing.

As with walling there is no set price for stock fencing with prices varying widely from £3-7 per metre. If for simplicity sake, and erring on the side of caution, we take a cost of £4/m as some sort of norm then the cost of fencing the same length would be £400 Hence the wall might only cost around twice as much as the fence.

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longevity

A well built wall should last well over 100 years, given a small amount of maintenance, you would be lucky if a fence lasts 15-20 years. Thus, even if a wall cost five times as much as a fence, it should be as cost effective (if not more so) in the long term. In this day and age it can be difficult to justify this level of outlay when it can only be economic in the long term. However any fence on anyone's land is going to need replacing at least once, if not twice within the landowner's lifetime. In instances where the cost of a wall is only around twice as expensive as a fence, it can represent a cost effective outlay in the relatively short term.

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Gapping

In some instances it is not necessary to completely rebuild the whole length of a wall in order to stock proof it. Returning to the above example, if only 50 metres of our 100 metres needed repairing this would effectively halve the cost of the wall, but it would still need lOOm. of fence as an alternative. Here the costs are almost identical for either method and the end result - if it is a well built wall - far more durable.

If the wall is lower than 1.3m it is likely to need a jump fence. Depending on the stock, terrain and actual height of the wall, this will either need to be a flying netting fence (i.e. netting 60-90 cm above ground on lower walls) or a barbed wire jump fence. Grant aiding is normally available for these fences at the same rate as the wall as they prevent stock damage. In the case of the flying fence the overall cost of wall plus fence is normally around the same as for the stock proof wall (less if the fenced wall is much lower); with a barbed wire jump fence the overall cost is normally lower than for a stock proof wall The expenditure on the wall repair is then all the more cost-effective, even in the short term.

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Craftsman Certification Scheme

The Dry Stone Walling Association (DSWA) operates the only national, graded, practical skill tests for walling - the Craftsman Certification Scheme. This has four levels:

Initial - Able to undertake minor works to a reasonable standard.

Intermediate - Able to undertake most general walling work to a good standard.

Advanced - A level indicating a high level of technical skill.

Master Craftsman - A high level of quality and technical expertise, able to tackle any walling problems.

The DSWA produces a booklet "Craftsman Certification Scheme "which deals with the scheme in greater detail. The DSWA can be found at www.dswa.org.uk

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