Roof access / safe trimming of wooden eaves

[markocosic]

I will need to trim the edge of our (wooden) roof once it's gone through a few movement cycles / settled.

 

I haven't worked out how to do this safely yet. Any advice?

 

It's two of layers of ROUGH cut boards. They are nominally 25*150 but 22-28*140-150 mm in practice so a little higgledy piggledy. (charming as the wife reminds me)

 

I will need to cut both. At the moment the lower layer is LONG by around 200 mm and has a toe board screwed to the "scrap" side. The upper layer is long by 50 mm or so. (I dropped these against the toe board to hold whilst fitting)

 

It's 3.6 metres above some deck support structure (all along house) and 4.5-5.5 metres above ground level.

 

I'm not skilled enough to eyeball a chalk line over the "charming" terrain of these boards. It will need a guide of some sort.

 

The wall cladding will dictate the final cut. There will be a "trim" perpendicular to the underside of the roof. I could probably drill screwholes for this trim through the roof boards, screw into a guide batten on the top of the roof, then remove and reuse screwholes for the trim piece.

 

I could also rough cut to say 75 mm projection then make some kind of guide that reaches under the free end and runs against the "trim" underneath the roof. (the boards are to overhang the trim 50 mm)

 

How would you approach this cut?

 

We have ladders. Cantilevering a "scaffold" off the wall is also an option. The ridge is structural and I can throw a rope over it and comfortably squat on the roof in a harness

 

Cut is ~16 metres long each eaves.

 

How would you approach this?

 

 

The framers...used a short bar petrol chainsaw for final trimming of rafters. No ta to copying that!

 

Coming from underneath with a circular saw sounds insane. Maybe not. The good side of the cut would be on top too. Never seen it done and there's probably a reason.

 

I can't decide whether harness and chop off loose ends (I'm right handed so the bigger flatter part of the saw would be on the "keep" side this way) or ladder/scaffold and reaching over the bits you're removing (would need to work left handed to keep bigger part of the saw base on the "keep" side) will be better.

 

(New) hand saw also an option. Slow but safe and I suspect easier to eyeball to a chalk line on lumpy wood. Maybe this for 2x 16 metre cuts in softwood? Get a nice flat angle on the saw from up on roof to span multiple boards?

 

Answers on a post card welcome!

 

 

 

[Declan52]

Hire out a few boxes of scaffolding and do it right. No hanging of ropes tied to chimney stacks or the neighbours tree type operations. You will be able to get a much better look at what is needed and then actually do the work right plus much much safer.  For the sake of a few hundred quid do it safe. 

[markc]

Circular saw and spider access platform, saves all the scaffolding hassle

[Mr Punter]

Scaffold tower and get Mrs to wheel you along between cuts.

[markocosic]

Spider access platforms look awesome! (not seen those before)

 

 

I've had a play at ground level and decided that I'm more afraid of the circular saw than the gravity. The difficultly in cutting these ends are:

 

(1) there's nothing flat to run the saw shoe over so you're liable to tip the nose of the saw shoe into a valley or are trying to hold the saw in mid air...unless you add some hardboard "rails" to smooth out the gaps

 

(2) there's some force in there from me strong-arming the banana wood where I want it that gets released as you cut and wants to throw the saw at you

 

(3) you'r working backwards in that either the main body of the saw shoe is on the "keep" side but you're staring at the "discard" side of the saw when running it (reaching over the blade) or the main body of the saw shoe is on the "discard" side and you're again trying to hold the saw in mid air (running a narrow strip of the shoe against the keep side...unless you deliberately cut the roof in sections and have some sort of support to hold the saw

 

Therefore:

 

Circular saw...and a track to run it along that can span say a metre...so that you can run the main body of the saw shoe on the "discard" side without worrying about the saw wobbling left/right or the front of the saw shoe dipping into the "grooves" in the roof.

 

Clamp some temporary 70x25 mm battens into the roof "grooves" to support the track. Cut the roof boards between the battens. Move on.

 

 

And do this from the wall side rather than the roof side. I don't think scaffolding. Not worth the hassle of getting it to the forest vs making a quick "clip on balcony" from scrap and hanging it from the wall. There's a 150x25 mm "batten" at the top that's fixed to each stud with a 6 x 140 mm screws (for carrying the weight of the wall cladding - more than enough for a person) that runs the full length of the roof. 

 

 

[markocosic]

Pleased with how the ridge turned out at the other end.

 

I was dreading fitting "6 metre ridge tiles" but they lined up great in the end. ?

 

Yes rope for getting up to the ridge. Harness too. (save for the no tools photo) Scaffolding that would be epic; ladders are dangerous; spider rig would be amazing but haven't seen them locally.

[markocosic]

Here's how the first eave cut turned out in the end for what it's worth:

 

 

Tried a 150 mm circ saw; ended up settling in a 190 mm circ saw as the larger foot / bed rode over the gaps more easily.

 

Measured from ridge, 2.5m straight edge fixed...to roof with screws, the run along that in a couple of goes with the circ saw atop a ladder. Nowhere near as much of a pain as I had imagined. (measuring is more of a pain that cutting, and painting cut ends more of a pain than either of those)