Boundry Gutter method

[OrangeJuice09]

Hi,
Wondering if someone can help me with a gutter situation. I have a cavity wall on a kitchen extension, and the outer wall is on the boundary and I don't wish the gutter to overhang into the neighbours land.

I've seen box butter but these are when there is a parapet wall, the external wall at the moment is the same height as the internal wall and will need to be finished.
I was looking around and found the following design as per picture. It looks easier and cheaper as I can use a standard PVC gutter and all I will need to do is add some sort of metal flashing over the cavity. Is this feasible, otherwise I will need to build a box and line it with lead which is a bit more complex.

 

[noseall]

Hi,
Wondering if someone can help me with a gutter situation. I have a cavity wall on a kitchen extension, and the outer wall is on the boundary and I don't wish the gutter to overhang into the neighbours land.

I've seen box butter but these are when there is a parapet wall, the external wall at the moment is the same height as the internal wall and will need to be finished.
I was looking around and found the following design as per picture. It looks easier and cheaper as I can use a standard PVC gutter and all I will need to do is add some sort of metal flashing over the cavity. Is this feasible, otherwise I will need to build a box and line it with lead which is a bit more complex.

View attachment 271661

Yes its feasible - ugly but feasible. The way that flashing bends in the image is silly. You would simplify it with a fascia that extended down to the closed cavity. You would also fix your lead flashing tray prior to fitting the fascia. You'll likely end up with water staining down the external wall, also unless you can accommodate a drip. And maybe add a small fall to the base of the flashing tray with say a piece of ply extending across to the base of the wall plate and fixed to it .

 

[OrangeJuice09]

Thanks for the above. I was going to use a 1mm aluminium sheet to provide the flashing as I can bend it easily, and then add a few fixings to hold it in place.
If I use lead, does it need to be code 3 or 4?

 

[^woody^]

That drawing shows the principle, but the detail needs refining to remove the cold bridge at the internal leaf, standing water on the metal capping and lack of drip.

Regarding your alternative option, you can't 'line a box with lead'. Lead gutters need to be in strips to allow for expansion and stepped, otherwise expansion joints need to be welded in and these defeat the point of using lead in the first place. Likewise if using lead for the capping.

 

[datarebal]

Get a sheet metal company to make a aluminium box gutter, they will put an outlet or two where ever you want. You won't get leaking joints and will get hood capacity .we have had 5.5 MTR made to suit for £450 plus vat ..

 

[datarebal]

If you use lead, you would use neoprene expansion joints .. by the time you buy that alone would cost more than a made to measure ally box gutter .

 

[^woody^]

I suspect that the issue is more the eaves design, not the guttering

 

[OrangeJuice09]

Here is the updated design that I plan to follow. The gutter is the standard uPVC although it will be the deep version.