Aug 24

Damp and fungal decay survey at historic mill 

Premier Heritage are pleased to have been appointed to undertake Timber and Damp surveys of the former Tonedale Textiles Mill in Wellington, Somerset.

Tonedale Mill was established in 1790 by the Fox family and was, for many years, the largest integrated woollen mill in the South West employing around 2000 local residents. The original site extended to approximately 12.6 acres and provided a range of stone and brick built Grade II and Grade II* Listed buildings.

Tonedale Mill

Tonedale Mill

The Mill is of particular historic significance as it retains a full complement of buildings representing the complete manufacturing process, from processing the raw wool through to yarn spinning and the preparation of woollen and worsted cloths. During the Boer War the Tonedale dyers also developed the dye ‘khaki’ leading to the end of British soldiers’ “redcoats”.

Evidence also remains of the development of different forms of power generation: from the early water powered mill, to the steam powered mills and finally to the electrical generating complex in the centre of the site. The mills also had specialist buildings for the manufacture of metal and timber components for both buildings and machinery maintenance.

The property now benefits from detailed planning permission and listed building consent and Hydon ( )and their joint venture partner, Kenmore Homes, are developing in excess of 150 residential units and also commercial space, combining some minor new build with a sensitive conversion of the existing buildings, maintaining much of the original internal fabric.

As with many sites of this type, it has fallen into a state of disrepair and various buildings are now affected by significant damp ingress and varying forms of fungal decay, including dry rot.

Premier Heritage have been employed to initially undertake the timber and damp condition reports on the various stone and brick built buildings, which will include the inspection of over 800 original windows, all of which are to be completely renovated.

Aug 24
Wood wasp feeding on timber

Wood wasp feeding on timber

Although not strictly speaking a Heritage Survey, whilst undertaking a recent survey of a Edwardian house in Sussex, we were asked by our clients neighbour if we could take a quick look at and advise on a particular problem affecting her timber framed Conservatory.

 The conservatory which was situated on the side of a 1950’s bungalow was constructed in soft wood, although was not of particularly good quality or was it well constructed. Wet rot decay (white rot) was occurring to the lower frames and cills as a consequence of condensation running from the internal faces of the glass during the winter and soaking the timber. A 10 year guarantee was originally provided by the installer (a franchise conservatory company), although they had long since ceased trading.

Nothing unusual about that you might think, but the owner also pointed out that insect’s, described as ‘wasp like’ were also burrowing into the timbers.

The wasp in question, although not your normal Wood Wasp, was chewing quite happily through the apparently sound paintwork and

timber and within a matter of minutes (and long enough to take his photo) was up to his head and shoulders and well into the softwood frame.

Damage caused by wood wasp

Damage caused by wood wasp

After several attempts and about 15 minutes chasing the insect around the garden, it was finally caught and identified, as what was believed to be a Wasp of the genus specie ‘Ectemnius’. This is a Wasp that lay their eggs on paralysed flies, which they then store in burrows made in rotting timber, hence its interest in this rotting softwood conservatory.

We advised the owner of the conservatory that in our opinion the frames of the conservatory were considered to be beyond economical repair and removing the decayed timbers would remove the risk of further infestation by the wasps. Recommendations were made to have the frames fully replaced with a more durable timber, with suitable treatment and decoration.

  To learn more about wood wasps click here Below is a short video showing a wood wasp in action!

Jul 15

Premier Heritage invest in the latest technology for non destructive timber surveys

Micro Drilling for the Structural Assessment of Timber

Many if not all period buildings retain large structural roof and floor timbers, which are vulnerable to moisture penetration, which if undetected can lead to wet /dry rot fungal decay and insect attack, resulting in their structural failure and considerable repair costs. Whilst these defects can sometimes be obvious, where timbers are built into large dimension walls (such as truss ends, bearers etc) deterioration can some times go un-noticed until the inevitable occurs.

non destructive timber survey with a micro drill

non destructive timber survey with a micro drill

What is Micro Drilling?

Micro drilling is a non-destructive investigation technique allowing the structural assessment of timbers and areas that can be hidden or obstructed by decorative finishes or plasterwork and can allow for cost effective care and repair of buildings without the loss of building fabric, which is extremely important when dealing with period or buildings of historic interest.

The Micro Drill cuts a fine 1mm probe into the timber to be investigated and through measuring the speed of penetration, records variations and defects in the timber caused by insect attack, fungal decay or other defects to a computer or field printer, allowing accurate assessment of the timber without the need for full destructive opening up.

This system of non-destructive investigation is of benefit when trying to assess the condition of built in timbers such as truss ends, bearer beams and lintels etc. and can also be used for large dimension joinery timbers. The system can be of great value to Architects, Engineers and Surveyors when proposing conversion, refurbishment and repair schemes of period and historic buildings as it allows minimal interference and the ability to provide conservation approaches to the repair strategy.

To arrange a non destructive timber survey call 0800 0 199 211 or click here to book a survey on-line.

Jun 24


woodworm323456Debate has raged about the scale of the woodworm problem and whether central heating controls it for many years.

Now the matter can finally be settled by the publication of actual data collated by Paul Carter CTIS CRDS A. Inst. MBM of Premier Heritage.

Claims that woodworm is effectively no longer a problem and that central heating controls woodworm are now demolished. It is now clear that woodworm remains a widespread threat to the nation’s homes and architectural heritage. It is also clear that woodworm is not controlled by central heating – and there is even the prospect that central heating actually makes the problem worse.

Active woodworm in a loft

Active woodworm in a loft

The Truth about Woodworm Study:

The Media report that the use of central heating creates conditions unsuitable for the survival of woodworm in housing appeared with increasing frequency in the early part of the decade. It was further suggested that as a consequence the incidence of woodworm activity in houses had become rare.
No data or other scientific works were advanced to support the postulations, which on the one hand gained apparent credibility by repetition but on the other were dismissed as being  counter-intuitive and unsupported by anecdotal evidence.
Investigations and data collations were conducted by Premier Heritage, with the purpose of 1, establishing whether or not data supported the hypotheses propounded in the media and 2, if they were, supported to investigate whether central heating could be employed as an active medium for the eradication  of woodworm infestations in houses.
The findings are contained below: 



‘Woodworm’ can mean any wood-boring beetle, but is generally used to refer to the Common Furniture Beetle (Anobium punctatum).
Surveys of properties were conducted in 2001 and preliminary findings published. Further surveys were conducted in 2002, 2003, (resources were not available in 2004) and 2005. 

Damage caused by woodworm

Damage caused by woodworm

The beetle activity was denoted by the presence of new emergence holes and insect frass.
In 2001, 2002 and 2003, each property was the subject of examination of roof and ground floor timbers. Not all ground floor timbers were available for monitoring. In 2005 only roof voids were investigated.

Where properties had central heating systems, they had been installed for over 20 years and the effects of such heating would have been well established. Surveys were carried out when heating systems would have been in full use.
Further data recorded included the relative humidity in the roof voids and moisture content of the timbers.


  • Timber is hygroscopic, which means its standing air-dry moisture content varies with changes in the surrounding humidity – as the humidity goes up so does the moisture content of the timber, and humidity is partially governed by the external environment and will vary substantially throughout the year.
  • In the substantial majority, roof and floor timbers had moisture contents in excess of 12% despite the influence of central heating.
  • Wood does not have a ‘static’ moisture content and the moisture level will vary considerably throughout the year, with or without central heating.
  • The majority of properties investigated were in the course of pre-purchase surveys. Of 204 houses inspected, 145 were suffering active wood-boring beetle infestations (71%). Within this, 118 out of 153 centrally heated houses (77%) were affected, while 27 out of 51 without central heating (53%) were affected.


  • There is no evidence that the use of central heating creates conditions unsuitable for the survival of woodworm in houses.
  • Central heating cannot be employed as an active medium for the eradication of woodworm in houses.
  • The moisture readings obtained in the timbers of centrally heated houses suggest that central heating may actually increase moisture levels in timber.
  • The incidence of woodworm remains widespread.