With our rafters in place we can move on to making the building weather tight. First job is fit the out riggers that are going to act as our roof overhang, and give our straw bales a ‘good hat’. They also mean that the gutter is outside the building shell, meaning they if there where a leak in the gutter, it shouldn’t leak into the building.
The outrigger on the east & west side where then simply fixed to the rafters, and lined up to get them all level.
As part of our roof build up we are having a breather membrane above our rafters with a 50mm ventilation gap to move any water vapour out of the building. To install the breather membrane we first rolled out our ‘paper’ over the rafter at the lowest point before being stapled into place. Before we could lay the next stage of paper we nailed some temporary batters to give our selves something to work off (we are not all nimble mountain goats, like our pet roofer and all round good guy Joe Duirwyn! (part of Hartwyn.co.uk, along with Jeffery).
Side note, batterns go at 90° to the rafters, counter batters run in the same direction as the rafters. But are called counter batters because they are counter to the normal plane of batterns.
We next installed outriggers to the north & south side on our roof. These can then be used as a ladder to help us move up and down the roof.
I have to say it’s a shame we can’t incorporate a roof deck up here because the views are amazing!
For our main roofing deck we have chosen to use waney edge larch boards for the following reasons;
- Larch is a very hardwearing board due to the high sap content and should need no further protection.
- It has only been rough sawn, so therefore has minimal embodied energy compared to sheet materials.
- It is half the price of the equivalent sheet material.
- It gives us a beautiful soffit detail when looking at the soffit of the overhang and just generally looks better in my opinion.
We installed our waney edge board at a 45°, both for strength and to give us a nice soffit detail when viewed from below.
As is a very old tradition with roofing, we had a topping out ceremony. This involved a branch of a mighty oak tree, and a wee bit of bubbly.