S Godfrey

Thank you for your reply A_L

Just checked the Gypsum website and it was very useful. Thank you for your advice nod

Thank you for your reply nod. So if I went with 100mm Recticel with 62.5 mm insulated plasterboard, do you know what sort of U value that would give me? Could I get away with say 50mm insulated plasterboard or would that not give me the required U value?

Would be grateful for some advice please. I am currently considering the issue of insulating the vaulted ceiling in my extension. I understand that the U value I need to achieve is 0.18 W/m2k. The specification from my planner states that I should use 120mm of Jablite with a further layer of 50mm Jablite under 12.5mm plasterboard. I would rather use Celotex or Recticel which I believe are better products. It is my understanding that the additional layer of insulation beneath the plasterboard is required to prevent thermal bridging. If for example I was to use 100mm Recticel or Celotex between the joists, could I achieve the required U value by using something like Knauf insulated plasterboard instead of a separate layer beneath the plasterboard? I realise that this may end up being more expensive but it would be much easier to fit. Many thanks.

Thanks Peter

Thanks Nod. Peter W - sorry if my questions seem a bit daft but what is PIR? Also would three layers mean the gutter would protrude too high to fit under the tiles? What sort of thickness OSB would be most suitable? Thank you

Thank you Joe

Good morning everyone. This is my first post on this forum. I am currently in the process of planning an extension to my property. While I will be employing the services of professionals with some aspects of the job I am trying to do as much work as I can myself to try to keep costs under control. We live in a 1950’s semi detached bungalow. Across one half of the rear of the property is a large hipped roof extension which forms the living room. We want to extend the adjacent kitchen across the other half of the property but the new build will extend only up to approximately 2/3 the length of the existing extension. We want to build a gable end on the new extension so we can vault the ceiling. The problem is what do we do about the guttering between the two hips? As the new build will not extend the full length of the existing extension we will need to install a right angle on the valley/box gutter to enable the water to drain into the existing gutter on the older extension. I had thought about fabricating a valley gutter out of fibreglass. Would this be the best solution? Thank you

Hello everyone. I am new to this site. I am currently planning a kitchen extension. I joined the forum as I have some technical issues with the design of the new build and hopefully I can get some advice from other forum users.