Hi,
Background
We've recently moved into a 1980's built bungalow.
The loft is a standard truss design extending about 10m in length.
There is a layer of non breathable old type felt below the roof tiles. The loft is ventilated on one side by a full length trench vent. On the other side, the same style vent has been covered by a flat roof extension. To compensate, tile vents have been installed in the main roof and soffit vents in the flat roof. However, this side suffers from heavy condensation on the underside of the roofing felt.
There is roughly 300mm of mineral wall type insulation on the loft floor. It has been boarded over in the centre for storage.
What we want...
We want to make this a warm loft. We run a business from home and have always kept our stock in the loft. This wasn't a problem in our old house. The loft was great. But here, the items are becoming cold (brittle) and worse, damp. We would like to convert to a warm loft area.
The idea
Based on the construction of our old loft, we would like to insulate on the rafters, leaving 50mm+ space behind for airflow. This would be done with foil backed Kingspan or similar. We would seal with tape. And remove the mineral wall insulation from the joists to allow heat up into the loft.
Would this work?
Does this sound like a good idea? We are very concerned about the condensation. The answer to that seems to be more ventilation, but because we want a warm loft, we would rather try and control it using the Kingspan as a vapour layer and of course, to further protect our items. Would condensation form on the 'warm side' of the Kingspan?
Basically just looking for any type of advice you can offer. Have read so many conflicting opinions on what to do, I just don't know.
Thanks!
Background
We've recently moved into a 1980's built bungalow.
The loft is a standard truss design extending about 10m in length.
There is a layer of non breathable old type felt below the roof tiles. The loft is ventilated on one side by a full length trench vent. On the other side, the same style vent has been covered by a flat roof extension. To compensate, tile vents have been installed in the main roof and soffit vents in the flat roof. However, this side suffers from heavy condensation on the underside of the roofing felt.
There is roughly 300mm of mineral wall type insulation on the loft floor. It has been boarded over in the centre for storage.
What we want...
We want to make this a warm loft. We run a business from home and have always kept our stock in the loft. This wasn't a problem in our old house. The loft was great. But here, the items are becoming cold (brittle) and worse, damp. We would like to convert to a warm loft area.
The idea
Based on the construction of our old loft, we would like to insulate on the rafters, leaving 50mm+ space behind for airflow. This would be done with foil backed Kingspan or similar. We would seal with tape. And remove the mineral wall insulation from the joists to allow heat up into the loft.
Would this work?
Does this sound like a good idea? We are very concerned about the condensation. The answer to that seems to be more ventilation, but because we want a warm loft, we would rather try and control it using the Kingspan as a vapour layer and of course, to further protect our items. Would condensation form on the 'warm side' of the Kingspan?
Basically just looking for any type of advice you can offer. Have read so many conflicting opinions on what to do, I just don't know.
Thanks!
