Roof structure completed

The last couple of weeks have concentrated on finishing the roof structure in preparation for the zinc sheeting finish.

The rafters have been clad with sterling board (or OSB) a Forestry Stewardship Council (FSC) approved product. Initially gaps were left over the parts of the roof where insulation was required because it was easier to install the insulation from above rather than below.

The roof (seen here) together with the walls and floor are being insulated with 200mm of insulation made from 60% sheep's wool and 40% recycled polyester plastic.

This picture shows the roof almost ready for the zinc sheeting. The OSB has been covered by a layer of plywood separated by 50mm batons to create a vented cavity. The plywood has been temporarily covered with polythene sheet (as on the left hand side above) to keep the roof dry. The zinc is the final layer. Now the roof is watertight work inside can start in earnest with 'first fix' electrics and plumbing.

Up on the roof it is really apparent just how close the neighbouring trees are. This one is literally 100mm from the edge of the roof!

These last two pictures again illustrate just what a snug fit the building is amongst the trees, something that would have been impossible with a more conventional foundation design.

With only 7 weeks to the target completion date and opening it is going to be very close. The zinc roofing company are booked to start in early June and the windows and doors were ordered a couple of weeks ago with a 4/5 week delivery so fingers crossed it can still be finished on time!

Roof structure takes shape

Now that all the bank holidays are out of the way the build is progressing very quickly. The target date for completion is only 7 weeks away so still a great deal to do.

The form of the building is now quite apparent with the rafters defining the shape of the roof and the overlap of the two sections of roof. 

The oak posts and beams support the principal rafters. All the oak will remain exposed while the douglas fir will be hidden from view. Inverted 'T' shaped metal plates have been used to secure the posts to the floor structure. These are inserted into a slot cut into the base of the post.

To prevent any lateral sway movement in the frame, these stainless steel plates had to be bolted onto the oak frame. Stainless steel has been used because it will not react with the oak (as mild steel would).

The roof from above.

On Friday we were very pleased to be able to show our Patron, President and Chairman how the project was progressing. Above (from left to right) Sir Kenneth Carlisle (SWT Chairman), The Earl of Cranbrook (SWT President), Lord Tollemache (SWT Patron) accompanied by Julian Roughton (SWT Chief Executive) and Pete Fordham (Bradfield Woods Warden).