Does a degree or 2 make a difference

[padstar]

OK so this is what i am looking at. using a 35' pitch and 1.59m from edge of wall plate to outer side of inner skin (where wall plate will sit). The online calculator shows that the top of the rafter will sit 1.26m above top of wall plate that the birds mouth sits on. I have a window cill at 1.3m. So assuming i have a batten, tile and 100mm flashing above the rafter i need the top of the rafter to sit 1.10 - 1.15m above wall plate.

Is the best thing to do just to remove 1 row of blocks to drop the external wall plate down and allow me the room between the top of the roof and window cill? I dont want to risk issues later down the line if its a relatively easy fix now. What do you reckon?

 

[padstar]

Or find a tile that is rated at a 30 degree pitch. Would there be much to chose from?

 

[padstar]

Now the OP has an option to fit the roof at 35°, and I can't see a valid reason no to. This "have a proper flashing detail" is a bit woolly, as he could have a proper flashing detail wherever the roof went.

Existing window cill levels on that elevation will make it difficult hence the question. If it was a simple as just throw it up at 35 degrees and get a flashing on top I would obviously do it. Have no desire to reduce it other than for that.

There seem to be similar looking tiles that have a 30 degree rating. Any reason not to use them?

 

[^woody^]

And how will you deal with the junction of two roof planes of different pitches?

 

[padstar]

Can 2 roofs at different pitches not meet at a valley? There are several down the road that appear to.

 

[^woody^]

The question is which looks the crapist.

Different tiles
Different roof angles and misaligned coursing
Flashing stepped under cill

 

[padstar]

The angle of the existing cat trap roof is 41' so the 2 will never be the same angle.

What I think is;
~ new roof at 30' pitch which gives about 200mm from top of roof to window cill
~ The entire roof is being re tiled so all tiles will be the same type
~ open lead valley so whilst tile coursing will be different they will be broken by the valley

Does that sound like the best solution?

 

[^woody^]

Re-draw your sketchup model, only do it accurately so that you can see the roof differences, the tiles (import a bitmap) and the position of the windows and flashing

 

[padstar]

This is as accurate as i am able to draw it. I think the angles of the roof are as planned (30' to the extension 41' from existing down to extension).

It allows for a 100mm flashing upstand and also leaves 100mm from top of flashing to underside of window. I havent done the cladding and doors etc as i am under it.

95% of the 30' roof sits over the garage.

 

[noseall]

Think of cars

Lol, please don't think of cars. Think of roofs, rain, snow, frost, sanity and the correct pitch. Ignore jonny.