Pitch of this roof?

[goldeagle]

I need to replace a roof to an old 1930's extensiondue to leaks, and wanted to stay with a tiled roof. However, my roofer has explained that the pitch is too low for tiling and requires a flat roof.

I measured the roof at about 12.5 degrees pitch so thought I could go for Centurian low pitch tiles, but roofer has measured the pitch and said it's about 6 degrees. I am sure my roofer is right but would like to know how I am measuring the pitch incorrectly.

Picture below - measuring it on the screen I get 122 length and 27 height along the black lines I have marked out which gives me 12.5 degrees. What am I doing wrong?? I have assumed the fascia pitch matches the rafter pitch, is that where I am going wrong?

Untitled

• goldeagle
• 25 Aug 2014
• 2

 

[alan333]

Measure the job. It seems the height is just over one course of blocks. Measure a course of blocks at ground level, and measure the horizontal length. Then do the math again, thus double checking your pic measurements.

 

[munchingB]

that is near 15 degrees not 6!

there are pitch calculators online if you google, but you'll need to do a couple of measurements.

 

[terrypin]

Edited

 

[terrypin]

I make it approx 12, though this is a guesstimate based on block size(?)

 

[theoldun]

If your measurements are correct, converted to metric = 3030 run and 685 rise = 12.7 degrees and slope of 3126.
However if you have measured down the slope and not the run then pitch will be 12.9 degrees.
You can tell just by looking at slope that it is approx 12 degrees
Regards oldun
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[goldeagle]

The course heights are 30cm and total width of the wall is 223cm. I reckon even taking into account a bit of measurement error it must still be over 10 degrees.

Thanks for the comments, gives me a bit of confidence that the roof will be ok for centurion tiles. Think I need to get another couple of roofers round and get them to have a look at the pitch. Otherwise I am looking at close to £7k to get the roof pitch raised and a new roof!

 

[xr4x4]

An iPhone will measure pitch/angle.