My experience is almost the reverse of Ian's.

Virtually no movement in the house. The brick section is double and cavity brick onto 18" sandstone foundations that sit directly on massive (solid) dolerite. For the weatherboard extension the piles are directly onto the dolerite. The exterior of the weatherboards are well painted and the entire wall is well sealed against the weather.

Most of the nails that have popped were on the lee wall - the weather wall is brick. My guess is that the moisture in the weatherboards would come mainly from humidity and this would be similar for all walls.

I replaced steel bullet heads with thicker galvanised nails. Given the age of the extension it was probably done with air dried weatherboards (wedge shaped) onto green Tas oak framing.



Fair Winds

Graeme