Services
Sampling usually takes between 3-4 hours. Small, just 5mm diameter cores from trees and 12mm diameter cores from building timbers are taken.
Dendrochronology results are presented in full colour written reports, which generally include a floor plan and photographic record of sample locations.
Where dating is successful a certificate of dendrochronological provenance is also issued.
Building dates are normally also published in Vernacular Architecture.
Further details on various aspects of our services are listed below: -
- Historic buildings dating
- Live tree, veteran tree, or woodland analysis
- Churchyard yew tree dating analysis
- Postal service
- Professional reports
- Dendrochronological research
Historic buildings dating
Our call out service begins with a survey to identify potential timbers and, where agreed to proceed, includes the specialist drilling of 12mm and 15mm cores from the timbers for analysis. The removal of cores does not affect the structural integrity of timbers, but if desired for cosmetic reasons, plugging and restoration of core holes is charged at an additional cost of £5.00 per core hole.
Example of tree-ring sequences revealed through the sanding of extracted cores
No payment (except the assessment/call-out fee) is required for any number of samples taken on-site and you are only subsequently invoiced for samples actually dated. This means that in the unfortunate event that samples cannot be dated you will incur no further charge.
The English Heritage guidelines document on dendrochronology states that "Where possible, at least eight to ten timbers should be sampled per building or, for more complex buildings per phase". To maximise the potential of dating a building phase we preferentially take 10 samples.
Our prices remain keen. By way of comparison with our charging structure, an estimated un-itemised fee of between £500 and £750 was published in 1997 for dating a building or phase of building and this price was be payable whether or not the analysis was successful. Today, you are likely to pay between £800 and £1000 to date a phase of building, with any of the University associated dendrochronology laboratories in this country.
Live tree, veteran tree, or woodland analysis
The only precise way to determine the age of a living tree is to cross-date tree rings in increment cores that intersect the pith of the tree. Timbers are sampled using a 3-thread, 5.15mm core diameter Halglof increment borer to offers the same astonishing impact of absolute tree-ring dates as has been achieved with the dating of historic timber-framed buildings in this country. Two cores are taken from opposite sides of each tree up to 2m in girth. While the girth of our very largest trees (and hence the trees of greatest interest) may make it impossible to reach their piths with hand-driven increment borers, increment sampling still offers the most accurate empiric refinement to the estimation of a tree's age. The total cost of dating analysis (which includes call-out) is: £320 for up to 4 trees. Please contact us for an estimate on analysis of 5 trees or more.
Churchyard yew tree dating analysis
Timbers are sampled using a 3-thread, 5.15mm core diameter Halglof increment borer. Two cores are taken from opposite sides of each tree up to 2m in girth. Due to the irregular growth of hollow yew, four cores are taken from trees over 2m in girth at approximately the four main compass points. Additionally, adjacent younger yew trees are also sampled, see Thorley yew report for full methodology. The total analysis costs of dating a churchyard yew tree are £320.
Postal service
Where convenient, simply send your oak or pine samples by post, in a bubble wrap envelope or well wrapped parcel. Please ensure that all individual samples sent contain a minimum of 65 rings. This is considered the minimum of rings required (for a single sample) to produce a unique tree-ring width plot suitable to attempt the dating of individual samples by the technique of tree-ring analysis.
A section of oak containing sufficient number of rings for tree-ring analysis
A section of oak containing insufficient number of rings to attempt tree-ring analysis
If you wish your samples to be returned with your final report please enclose a stamped self addressed envelope. We send a dated acknowledgement of receipt for all samples received. For the postal service please ensure that:
- All samples sent are clearly labelled.
- Details of where each sample was taken from are enclosed.
- Wherever possible photographs of items or locations are sent for incorporation into certificates.
- You include your return address.
Professional reports
The full colour illustrated reports explain the methods and results, and includes interpretation, discussion, a floorplan and photographic record of sampling locations. Reports are charged at £10 per copy. (see the right margin to click and download some examples of our reports). Photographs, where supplied with posted samples are incorporated into the report to help identify timbers and location. Photographs of specific objects for dating provide an extremely useful means of identification and are normally incorporated into the certificate of dendrochronological provenance.
Dendrochronological research
Timbers that have sufficient rings to be dated using tree-ring analysis may nevertheless be impossible to date. Pollarding and other human disturbances can sometimes make timbers impossible to date by tree-ring analysis. Weaknesses in currently available reference chronologies may also make it difficult to date timbers from some areas at the present. Tree-ring dating continues to develop as a science and all samples which cannot be dated (at the present time) will be held by us and periodically reviewed in the hope that they will date in the future.
Unless prior to sampling a client specifically requests otherwise, Tree-Ring Services policy is to make its reports available to further research and to publish building dating results in Vernacular Architecture. To obtain copies of the journal Vernacular Architecture please contact: the Publications Officer, 16 Trefor Road, Aberystwyth, Dyfed, SY23 2EH.
Updated: 02/12/2008