David BaleOne of Norwich's best loved historic houses has reopened after a deep-clean - but museum bosses warned moths were still a danger to the exhibits.David Bale

One of Norwich's best loved historic houses has reopened after a deep-clean - but museum bosses warned moths were still a danger to the exhibits.

Strangers Hall, which is housed in a 14th century building and was once home to wealthy merchants and mayors, shut after the Christmas holidays.

Since then more than 30 staff and volunteers have worked tirelessly to check pest levels, assess and treat any damage and remove the dust that provides food for insects and bugs.

Staff also had to remove all the heavy furniture from the rooms with the cleaning plan designed by specialists from the Norfolk Museums and Archaeology Conservation (NMAS) department.

The museum reopened yesterday, but bosses said the deep-clean would become an annual exercise to keep a check on the moths that have also caused damage to exhibits at Norwich Castle Museum.

Sarah Goodwin, the museum's curatorial assistant, said: 'In each room, small objects were moved to holding areas where each item was cleaned very carefully with a paint brush and museum vacuum cleaner.

'Heavy objects were moved away from walls and to one side of the room and cleaned in the same way.

'Finally, each room was cleaned from top to bottom - again with a paint brush and vacuum - and the objects replaced.'

Conservationists however discovered that moths were still causing problems and there were a few isolated sources of suspected woodworm.

Dave Harvey, NMAS conservation officer, said: 'Regular cleaning of objects and room settings is a crucial part of collections care in museums.

'The deep clean of Strangers' Hall has significantly reduced the build-up of dust and debris that can lead to pest infestations.

'Layers of dust can also exacerbate the corrosion of metalwork over a period of time and encourage mould and fungal growth on organic material.

'In addition, the clean was an excellent opportunity to make a detailed conservation audit, identifying objects needing specialist attention.'

As reported, the museum was earmarked for closure in 2003 by Norfolk Museums Service as part of a raft of proposed cost cutting measures, but it was saved following widespread public opposition and a campaign by the Evening News.

Since then Stranger's Hall has gone from strength with 8,000 people visiting in 2008, and opening times being extended last year. The hall in Charing Cross is open from 10.30am until 4.30pm every Wednesday, Thursday, Friday and Saturday.

Stranger's Hall is believed to get its name from the refugees who came to Norwich from the Low Countries in the 16th and 17th centuries.

Strangers' Hall is celebrating the big clean-up with a chance for children to learn more about the care of historic objects and to have a go at cleaning some of them. Children can also invent their own cleaning device and make an enormous model of it.

Activities take place today, tomorrow and Saturday from 10.30am to 3.30pm and are free with museum admission.

For more information visit www.museums.norfolk.gov.uk

Are you restoring a part of Norwich's heritage? Ring reporter David Bale on 01603 772427 or email david.bale2@archant.co.uk