Pitched EcoJoist Rafters

One size solutions don’t fit all. To prove it, here’s a project where the client specified Pitched EcoJoist Rafters.

The project was a large scale barn conversion in Andover, Hampshire. The initial enquiry to Robinson Manufacturing came in through an architect, but the home owner also became involved.

The barn in question has an oak framed interior. One of the homeowner’s priorities was to still be able to see these timbers once he moves into the property.Using lateral thinking, it became clear that specially customised Ecojoists offered a very effective solution to the client’s needs. We worked with the client and his engineers to create and fine tune the designs, including:

Originally the engineer had designed ecojoists to be sat on tilt fillet at the supports enabling the joists to be installed at a pitch. Remembering being shown a feature on our software which enables us to rotate the end block of the joists, designer James suggested an improved method of fitting the joists. The joists would now be installed at the correct pitch (42.5 degrees) but the end blocks which meet the supports will be rotated and sat at 90 degrees. This means that all of the roof loading is now being transferred vertically onto the supports rather that at an angle down the pitch of the roof. This is a much sturdier method of construction as previously the roof’s own weight would have been trying to pull itself off of its supports. Now the load is transferred vertically through the supports. Another benefit to this is the fact that we are now able to hide the supporting steel ridge beam within the roof without the use of a collar tie.

Challenges involved in the project included:

  • High loadings on first floor joists supporting partitions which run right up to the ridge.
  • High loadings on the end of cantilevered joists supporting large partitions.
  • Designing ecojoists rafters with rotated end blocks.
  • Full height window going through the first floor meant a lack of supports. The solution was to trim an area out using glulam beams which would be aesthetically pleasing when looking through the window.