Roof tile tolerance

[bt0558]

Hi

I hope someone can help.

I am planning a new roof as part of a loft conversion project.

I need to plan in advance and i have some flexibility with size of the soffit, bargeboard and fascia on the new gables which are themselves timber framed.

I need about 44 tiles and current choice is Marley Edgemere.

I am inclined to plan for 44 with a nominal cover width of 295mm with the soffit and fascia that results to make fitting them easier.

I understand that there is some tolerance and the tiles may be pushed together or or pulled apart as they are interlocking which would give a bit of give.

Is the 295 the average size of tile and therefore some bigger and some smaller, or is the 295mm the size of the tile when the interlocking is centred in its movement.

If the latter does anyone have a rule of thumb for the amount of tolerance i could use to plan for 44 tiles.

Any help appreciated thank you.

 

[Barthy]

Interlocking tiles generally have a maximum 2/3mm shunt each way (tolerance)
Are you worried about the finished verge if you start with a 50mm overhang of the starting verge.
How are you planning to finish your verges mortar or dry?

 

[bt0558]

Hi Barthy

Thanks for replying and for the info about the "shunt". I have learnt a new word today.

My plan is to dry finish the verges with either Marley, GAP or universal parts.

I have a square bungalow that i am extending 3 metres at the back, two hip to gables front and back and a loft conversion. I am putting 2 long shed dormers to the ridge covered in tiles as per to roof.

I am trying to tidy up the tiles so that the tiles fit the dormer including overhangs at the cheeks and also at both gable verges so it all looks pretty.

I have attached a sketchup snap.

I think with 2/3 mm shunt i can easily do it as i made the dormer just right.

I am worried how it will look with some tiles with the shunt open and others with it closed with Marley Edgemere.

I am happy to make some minor changes to dormer length and distance between verges / overhang at verges if there is more chance of it all being pretty.

Thanks