Last August I boarded out the loft in my 1930s bungalow. An area of 6m x 3m or so. The original ceiling joists are 4x2 at around 14” centres (ish) and I crossed them with some 3 x 2 equivalent CLS timbers at 600mm centres. Every intersection was packed so as not to pull on the existing joists and then they were screwed at every intersection. Then I installed Kingspan equivalent in between the gaps and left a 20mm gap between the ‘Kingspan’ and the boards for airflow. The boards were 18mm moisture resistant boards which were all screwed with staggered joints.
As the cold weather arrived, I noticed that there were cracks between the ceiling and the walls in the two bedrooms. No cracks in the inner ceiling areas, just around the edges. I’m wondering if this could be a temperature issue as the loft has vents which allow cold air in and make the loft very cold but now that I’ve insulated it, there’s a big temp difference between the 2 sides of the ceiling.
There’s a solid brick supporting wall from one end to the other where you see the original joists overlapping just right of centre in the pic below.
Happy to just leave it for now in case it’s just movement from the new timbers or something and then just fill the cracks.
As the cold weather arrived, I noticed that there were cracks between the ceiling and the walls in the two bedrooms. No cracks in the inner ceiling areas, just around the edges. I’m wondering if this could be a temperature issue as the loft has vents which allow cold air in and make the loft very cold but now that I’ve insulated it, there’s a big temp difference between the 2 sides of the ceiling.
There’s a solid brick supporting wall from one end to the other where you see the original joists overlapping just right of centre in the pic below.
Happy to just leave it for now in case it’s just movement from the new timbers or something and then just fill the cracks.