Timber Decking & Cladding Association (TDCA)

Severn Valley Woodworks decking and cladding products are TDCA performance rated

DeckMark and CladMark are quality assurance (QA) schemes created for the Timber Decking and Cladding Association in consultation with BM TRADA Certification. The schemes are based on existing quality assurance standards – ISO 9000, EN45011/12, ISO Guide 62/65 and are intended to help all those engaged in the specification, design, installation or purchasing of decking and cladding to ensure that the products they buy will be of the highest quality.

To ensure standards of performance are maintained, the accreditation of Severn Valley Woodworks Limited is audited and renewed every 12 months by an independent inspector appointed by the TDCA



  1. Provides assurance that the materials supplied as part of a timber deck or associated outdoor structure or timber cladding are quality, fit for purpose products
  2. Provides unambiguous evidence of compliance with good manufacturing practices required by the TDCA
  3. Provides architects, designers, and inspection authorities with the means of verifying quality assessed products
  4. Is an independent testimonial to workmanship
  5. Offers a means to resolve quality issues through the TDCA Dispute Resolution Service


To view copies of our certificates please click on images to the right.