Low pitch on new roof

Roofer said:
But the correct specification is for 20 degrees minimum

I have scaled it out on paper and the difference between the pitch of the slates and the pitch of the rafters is only about 1 degree (effectively each slate is 8mm higher at its tail than at its head)
Click to expand...

alastairreid asked in an earlier post and onions 1066 confirmed at 12:33am they were modern tiles. This is where I have been thrown as yes you are right if copper rivets have been used then there the fibre cements :oops: and the difference is only 3.5 degrees as Eternit have confirmed. So Mr joiner has messed up. It will need sorting.
 
Sounds like the roof has already been tried and tested to me, I would not do anything until a problem arises.
 
Roofer said:
But the correct specification is for 20 degrees minimum

I have scaled it out on paper and the difference between the pitch of the slates and the pitch of the rafters is only about 1 degree (effectively each slate is 8mm higher at its tail than at its head)
Click to expand...

So the question is do you think it will be ok? Bearing in mind these tiles are probably tested in a wind tunnel and they are always going to keep on the safe side when specing the tiles and I live in a built up area in the midland and we do get extremes of weather. If I keep convincing myself I'm sure it will be ok :?
 
This thread reminds one of the Medieval debate as to how many faries can dance on the head of a pin.
A few degrees won't make any difference. Its in a sheltered location and doesn't leak, so what's the problem?
If there is a problem, it will come from the building inspector checking Marley's data sheets, but we all know what building inspectors are.
 
tony1851 said:
This thread reminds one of the Medieval debate as to how many faries can dance on the head of a pin.
A few degrees won't make any difference. Its in a sheltered location and doesn't leak, so what's the problem?
If there is a problem, it will come from the building inspector checking Marley's data sheets, but we all know what building inspectors are.
Click to expand...

I like your reply that makes me feel a tad better
 
you can use an undertile system like the one from onduline which allows tiled roofs to be even shallower than normal ill have a look for it
 
The undertile systems such as onduline work, though produce a deeper roof.
However, from the tile manufacturer's point of view, the problem is not just one of keeping water out.
They have to consider the longevity of the tile itself. If the pitch is too low, the tile does not drain quite as easily as intended, and tends to remain damper for longer. This can be a problem in winter when frost comes.
I recently had occasion to do a roof with a pitch 3 deg lower than the recommended pitch, and the manufacturer refused to guarantee it. One suspects they may be overcautious, but a client may be prepared to take the risk that the tile may only last 40 years instead of 50. :)
 

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