Log cabin general

[Firetrap999]

I have read a lot of posts relating to log cabins and they have raised acouple of concerns,
1. i have put shingles on top of felt on top of 40mm kingspan, as recommended. the instructions on fitting shingles was virtually nil, other than pictograms on plastic packing and a google search for video on u tube.
do I need to mastic the shingles onto each other? They seem fine just nailed, but one post suggested using mastic??

2. I have 6" gap under floor, I have filled with polystyrene beads and the floor is not ventilated, should I drill a few holes around the cabins base and put some air vents in and reduce the fill to about 4" to give a 2" gap for air circulation??

 

[Deluks]

Shingles need to be nailed down. Nails don't hold very well in kingspan, you shoulda boarded over the kingspan first. You could try felt adhesive under the shingles, but it will be messy and take ages.

If you create an air gap between the beads and the floor, then you will be letting cold air in between the insulation and the area you are trying to insulate. will give you some protection from the cold ground I suppose so you might as well.

 

[Firetrap999]

I have used 50mm felt nails to go through kingspan and into 20mm t&g roofing, would have liked 55mm felt nails but not available, nearest is 60mm on line which I am using for the ridge (double thickness shingles).
yes, i agree, seems a little paradoxical to insulate and the create an air gap, but as you say it at least insulates cold from ground. might do a bit of flooring without air inlet and see how it performs before commiting, thanks again for your feedback.

 

[mysteryman]

I am no builder, but the polystyrene beads would I think allow enough air circulation to keep rot at bay. I suppose you could check the moisture content of the floor every now and then.