Drilling hole through angled soffit

[thomp1983]

Hi all,

I need to fit a new svp this week, it will run up the gable end wall and needs to finish above the roofline due to the gable window upstairs.

I don't want to swan neck it around the fascia as I don't like the look.

This means I need to drill a vertical hole through the soffit which will be at an angle to the svp. Is there a proper technique for this or is it just eye balling it as best as possible with a hole saw?

Thanks
Chris

 

[23vc]

I’d probably go multitool, although if it’s the hollow (tonge and groove look) soffit they’re pretty flimsy so be careful. Doesn’t this mean you’ll also need to do some kind of lead collar to flash it up through the tiles?

 

[^woody^]

Is the soffit asbestos?

If not, cut it from above with a hole saw or cutter.

 

[thomp1983]

It's hollow soffit, it's on the end of our new extension, cutting from above could work, guess I'd still need to eyeball a hole up through the soffit from below so I can see where to drill down to.

Yes I'll need to add a lead weathering covers to the tiles but that's not really an issue.

Thanks
Chris

 

[^woody^]

Be careful trying to cut hollow soffit when it's cold as it can chip very easy.

Fine teeth or a carbide or diamond saw and a very high speed, but there are collars available if you decide to rough cut the hole.

 

[thomp1983]

I'm expecting to fit a snap on collar below butting upto the soffit and a lead weathering cover on the tile above

 

[23vc]

Not sure how the snap on collar will work at an angle?

 

[23vc]

I’d go external AAV for less effort and faffing

 

[thomp1983]

AAV isn't an option, I'm the end of a 6 house sewer arrangement and non of the other houses have a vented svp so I will have to, I don't mind having it vented just need to get it through the soffit tidely.

I'm not sure how well a snap collar will work on an angle either, I suspect it'll need some fettling but there cheap enough to experiment with, worst case I'll get some white plastic and make something suitable with it and bond it in place.

 

[cdbe]

Put a bend on the bit through the roof.

 

[23vc]

Sure you’re already aware but a tight swan neck that just clears the fascia looks a lot neater than one with a massive offset and should be pretty discreet

 

[thomp1983]

Managed to get it done, ended up running the pipe up to just short of the soffit then used a straight edge to mark onto the soffit then eyeballed the centre with the hole saw.

Finished it with a pipe snug, had to cut the rubber fins off it so I was just left with the flanged piece then put a cut in the back of it, fixed it in place with sticky expanding foam and used some black mastic to cover the cut at the back.

BCO has signed it off, I'm happy with it and the wife just shrugged her shoulders as ever.