Rome wasn't built in a day and neither is a roof structure. The last blog post showed the 'barn-board' ceiling installed on top of the vigas, but a ceiling is not a roof. This post here continues the story.
One consideration when using the reclaimed barn-board was knot holes and irregular edging which upon installation resulted in minor gaps and see-through holes. I knew above the barn-board I would be installing a layer of rigid foam insulation and I didn't want to look-up at the ceiling and see the white foam board between any gaps or knot-holes.
My inexpensive solution was to purchase a roll of thick woven burlap fabric and layout on top of the barn-board, secured using a contractor's staple gun (see photo below).
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The next layer as mentioned was the application of QTY 8, 4'x 8' sheets of 1-1/2" thick rigid foam insulation. This R-tech insulation is insect and mold proof (see photo below). The insulation panels were held in place using wide-head nails.
The final layer for this phase was QTY 8, 4' x 8' sheet of 1/2", plywood. I need to trim the plywood at the edges where necessary and complete the securing of the plywood with wood screws.
The wall of the structure still needs to be build-up with cob (straw/clay) to roof height and waterproof and drainage. The summer rain monsoon season is fast approaching, bringing urgency to this phase of the project.