Hello All,
I would be very grateful if you could share your thoughts on the dilemma I am facing.
I have a small lean-to roof (porch extension), one plane, no ridge tiles. Rafters length is about 1.8m. Roof pitch is 22.2 degrees. I was planning to install Marley Ashmore interlocking tiles (https://www.marley.co.uk/products/concrete-tiles/ashmore) as the minimum pitch recommended by the manufacturer is 22.5 degrees. However my roofer complained that they will be "horrible" to lay.
The problem with the roof is that the original old wall to which the roof leans is not perpendicular to the side walls (while the front wall of the new extension is) resulting in roof being effectively a trapezium with 2 right angles and the roof length on the left-hand side being 2 inches longer than on the right-hand side. This is indeed quite a lot of out-of-squareness for such a small roof. All this means that the battens will need to be laid out in some kind of fan pattern. The roofers say that with interlocking tiles the fanning is not possible. I'm not quite sure of this.
So they tried to convince me that plain tiles should be installed, because with plain tiles there is plenty of room for adjustments and closing this 5cm. The minimum pitch for any plain tiles is 35 degrees, but they say that the manufacturers are too cautious and "it will be fine" and also gave me examples of existing installations where it's been done. It's hard for me to believe that going down from 35 to 22 degrees will not impact significantly the performance of the roof. I understand the problem with fanning of the interlocking tiles, but I don't want to have a poorly-performing roof.
The hole extension is done under the BC application so I'm not sure what the building inspector would say about installing plain tiles on 22 degrees pitched roof.
Could you please share your thoughts?
Thanks,
Luke
I would be very grateful if you could share your thoughts on the dilemma I am facing.
I have a small lean-to roof (porch extension), one plane, no ridge tiles. Rafters length is about 1.8m. Roof pitch is 22.2 degrees. I was planning to install Marley Ashmore interlocking tiles (https://www.marley.co.uk/products/concrete-tiles/ashmore) as the minimum pitch recommended by the manufacturer is 22.5 degrees. However my roofer complained that they will be "horrible" to lay.
The problem with the roof is that the original old wall to which the roof leans is not perpendicular to the side walls (while the front wall of the new extension is) resulting in roof being effectively a trapezium with 2 right angles and the roof length on the left-hand side being 2 inches longer than on the right-hand side. This is indeed quite a lot of out-of-squareness for such a small roof. All this means that the battens will need to be laid out in some kind of fan pattern. The roofers say that with interlocking tiles the fanning is not possible. I'm not quite sure of this.
So they tried to convince me that plain tiles should be installed, because with plain tiles there is plenty of room for adjustments and closing this 5cm. The minimum pitch for any plain tiles is 35 degrees, but they say that the manufacturers are too cautious and "it will be fine" and also gave me examples of existing installations where it's been done. It's hard for me to believe that going down from 35 to 22 degrees will not impact significantly the performance of the roof. I understand the problem with fanning of the interlocking tiles, but I don't want to have a poorly-performing roof.
The hole extension is done under the BC application so I'm not sure what the building inspector would say about installing plain tiles on 22 degrees pitched roof.
Could you please share your thoughts?
Thanks,
Luke