Porch pitched roof construction - overhang

[mturbo23]

Hi I am in the process of changing my porch roof from a flat roof to a single pitched roof and i need a bit of help as this is the first time I have done it.

I am using Marley plain concrete tiles but I am struggling to get the correct overhang (38-50mm from what i can find) without cutting the tiles, which id rather not do if possible.

The width of the roof is 3770mm and the width of the tile is 168mm + 3mm spacing gap between tiles. 3770 ÷ 171 (tile width + gap) = 22.04. Therefore i need 23 complete tiles but this gives me an overhang of roughly 84mm so is far too much.

What is my best solution?

I have also thought about using a dry verge system but does this also need the same overhang or can it be fitted flush with the cladding on the side?

Thanks

 

[Blagard]

Use a tile and a half tile on each row one end (248) and your problem is solved!
(21 x 171)+ 248

 

[mturbo23]

Thanks that does work out better. My only concern is that the overhang will be less than 30mm when I add the 12mm shiplap cladding to the side.

Maybe I am best to just make the roof slightly wider by about 20mm each side to accommodate the 22 standard tiles?

 

[Blagard]

The space between plain tiles is not that critical. You could open the joints just 1mm each and gain 20mm likewise if you closed the joint by 1mm you can loose 20mm. Also you need to watch out for manufacturing tolerances as that could give you a curve ball if you see what I mean!

If you that bothered about not cutting then you need to get the tiles and lay them out to check.

 

[mturbo23]

Thanks that's good to know. Like you say I think I might just try on the roof and see how they fit then adjust accordingly.

If I did choose to use a continuous dry verge system I take it I still need to have the correct overhang and couldn't fix straight to the cladding, as the overhang would be too small.

Cheers

 

[Blagard]

<snipped>If I did choose to use a continuous dry verge system I take it I still need to have the correct overhang and couldn't fix straight to the cladding, as the overhang would be too small.

I have not used a dry verge so that is one for some-one who has actually used it

 

[noseall]

The verge cloak overhang is not a critical measurement.

30mm is fine.

As said, don't forget to factor in tile 'n' halves.

Don't forget the eaves course (bottom) and the short course (top).

Fix your lead flashing (top) once you have fixed all the tile laths (battens) and before you tile. Just use a piece of timber the same thickness as your tiles to form the lead down onto, then bend it up out of the way whilst you fix the tiles.

 

[noseall]

Oops edit mistake!

 

[mturbo23]

Ok thats good then.

I take it if a row is 22 standard tiles and 1 tile and 1/2 when doing the eaves I need to cut one of the eaves tiles in half but not put it on the end, as there isn't enough to fix it it to?

Cheers

 

[Blagard]

Rather than use a 1/2 eaves tile you can simply take a tile and a half and cut the bottom off to the same length as an eaves tile

 

[noseall]

Rather than use a 1/2 eaves tile you can simply take a tile and a half and cut the bottom off to the same length as an eaves tile

That's what we do.
Also, you occasionally find the eaves tile is a little bit wider or narrower than its above counterparts. This means that on longer roof runs, you sometimes need to either chop or add a cut down tile 'n' half to compensate.

Not so much a problem on short runs.

 

[mturbo23]

Cheers for all the info all that's left now is to wait for some decent weather and and get on with it!