hip/ridge tiles (is nominal-angle that of roof or the tile itself?)

[foy9999]

Working on a customer's roof today and find I need to replace a 1m long cement-fibre 'slate'

The tiles that go with these cost about £2 despite being very large (Marley/Eternit/Cedral Thrutone)

The ridges are about £70 each.

Anyway the one I took off has an angle or 120 degrees.

You go online and they are listed in angles from 20-60 so you think 'well mb my 120 is a 60 as 180-120 = 60'

There aren't any in stock anywhere online so phone some local roofing outlets who don't know what they are. Eventually find one further away who thinks they might have one lying around and helpfully goes to look for it and rings back but is confused about the angle as the only info on it is '35 - 84'.

Anyway I drive about 2 hours to get it and measuring it it's a bit sharper than mine: 110 degrees (or 70 if you do it the other way)

So to get to the point of this thread am thinking 'how can that be as they are only listed from 20 - 60 degrees' and then I remember when you are buying verge-caps they are marked LH or RH in relation to standing facing the front or rear of the property, not the gable-end that you will be putting the caps on.

So.... is it perhaps the case with these that you buy the one that matches the pitch of your roof, not the angle of the actual ridge-tile?

I guess if you can do it a more complex way by halving the angle of the ridge tile then subtracting that from 90. So my 120 tile would be 60 on one side and taking that away from 90 would make it a 30

NB on old clay tiles the angle is scratched into the tile (like 110 or 105)

900mm cement fibre hip/ridge tile has 110 degree angle but they only list 20 to 60

35-84?

 

[Smallfry]

You need Roofman for this .......

I always thought that the nominal roof angle was taken from the horizontal, so your roof is nominally 30 degrees, so times that by 2 (two right angle triangles back to back) the angle at the top (ridge) of one of the triangles with then be 60 degrees. Times that by two and it gives 120 degrees.

I might be wrong, and there must be a simpler way. So I would think you need a 30, but don't buy anything on my estimates ! I would have though the merchant selling them would know ? But maybe thats a bit too much to expect these days ?

 

[minimutly]

@roofman ?
Oddly enough I have the same question, going to remove a chimney on parents house.

 

[roofman]

Night off from roofing tonight lads, so dragged this from google for you




To determine the angle of ridge needed, the following procedure should be followed. Add together the rafter pitch of each roof slope and take the result away from 180° (the sum of the angles of a triangle). The result will give you the angle of the roof structure at the apex.

 

[roofman]

Also choosing angles means nothing when you need to match the ridge line with next door even though you have renewed your own roof, i would say at least 30% of roofs have unmatched ridge tiles from the actual roof angle if Karen likes a particular style and colour

 

[foy9999]

Creating the thread helped me work it out.

You basically need to know the pitch of the roof (hip & ridge will probably differ) which isn't easy unless you knew you were going to have to establish that.

I actually told the customer in advance that if it was one of the hip tiles it would be very expensive and he ignored my email so I just took along some of the normal roof tiles then when I arrived and I asked which ones had slipped he said 'oh I don't know. a neighbour told me'

But basically the one I bought which says 35 on it matches the 110 measured because: 90-35 = 55 and 55 x 2 = 110

In one listing for these tiles they say: Available angles: 90°, 105°, 120°, 135°

and immediately below : Available in a range of angles between 15 and 60 degree

So it's a bit confusing but basically the bigger numbers are the actual angle of the tile and the smaller ones are the angle of the roof it would be used on.

And to answer someone else further up who raised the issue... I expect people on the end of a phone to know zero. They get paid no matter what happens so they don't give a fkuc. It's easier to just say all day long 'no we don't have them'

 

[Smallfry]

And to answer someone else further up who raised the issue... I expect people on the end of a phone to know zero. They get paid no matter what happens so they don't give a fkuc. It's easier to just say all day long 'no we don't have them'

Sadly, this seems to be the case with so many "specialist" suppliers of so many things these days

 

[foy9999]

Fwiw I fitted the tile and the difference between the 120/30 degree tile and the 110/35 degree one was quite marked

The remaining tiles on the hip are very weak and trying to push the sharper (new) one under the original shallower one would have caused it to split.

I therefore had to loosen the fixing bolt on the one above and not push the spigot fully home before securing the new one to the roof.

Would be nice to replace them all but I counted 21 so that's £1470 before labour

You can see on identical property across the road how many are required

new tile is clearly sharper than ones above and creates a gap at edges

 

[roofman]

Water marks down the hip board in the loft alert

 

[foy9999]

Water marks down the hip board in the loft alert

View attachment 427169

Don't think so Roofman as there's plenty cover where you've circled red

red circle area viewed with hip tile removed