Timber for roof finial

[Nelly111s]

I've been asked to make a roof finial. Dimensions overall are 1500mm long, 120mm square. It consists of a spike of 600mm and a 900 square section with turned ball. The construction should be straightforward, but Im not sure what the "best" timber for this would be. Clearly it's the sort of thing that will get little maintenance and some form of hardwood would give the longevity.
So, two questions really,

1. which species?
2. if this species is only available in section less than 120mm which I suspect is likely, is D4 glue the best to laminate 4 or 9 pieces to get the required section?

 

[Adam W.]

Oak. Heartwood only, no pith.

 

[johnnyb]

I used redwood soaked in preserver. it was glued up I think. the biggest thing was putting it on the roof as it needed ladders off the top level of scaffolding....gulp.

 

[johnnyb]

here it is being turned. and a photo showing the rot at the back. we replaced lots of other timber bits using accoya.

 

[Nelly111s]

Thanks @johnnyb. Any idea on the expected lifespan of the redwood? The current one has been on the roof for tens of years, may 100, so I need something that will last a minimum of 10 years ...
That finial looks similar to the one I've got to copy, although the "spike" is faceted rather than round (which would be easier and may be suggested to the customer!)

 

[johnnyb]

my aim is always the clearance time of a cheque.
the previous one was redwood. it lasted from 1907. its rotted because lazy painters didn't paint the bit you cannot see around the back. this obviously gets wet but also dries. maintenance is vital with all wood. oak wouldn't be my goto for this as it doesn't really take paint to well sapele may be better. iroko doesn't paint so well. maybe southern yellow pine or douglas fir. my choice would be a single chunk( if I had one)

 

[johnnyb]

I finish turned the finial using a sharp no5 plane as it gets rid of the discrepancies

 

[johnnyb]

a faceted finial would be interesting. at least you wouldn't be planing against the grain! my lathe does have an index wheel that would make marking out a doddle. the rest would be hard graft.whose gonna notice up there?

 

[Nelly111s]

I doubt anyone would notice. My lathe also has an indexer, but I did think I may be better making it out of six staves using a jig on the thicknesser. Not sure which would be easier / better. Depends if I can get suitable timber in the right cross-section.

 

[johnnyb]

if I couldn't make it in one piece Id make it round.

 

[gregmcateer]

Larch , red cedar, or as johnnyb says above. Esp if being painted

 

[Nelly111s]

This is what the original looks like

 

[johnnyb]

if its 8 sided I'd make using the sawbench and a taper jig. it doesn't look to chunky at the taper.

 

[Doug71]

Definitely Accoya if I was doing it.

 

[Nelly111s]

Definitely Accoya if I was doing it.

I've never used Accoya. Does it turn OK (for the ball at the end)?
Also, is it widely available - I'm in NW England and not seen it in any local merchants (but maybe not looked hard enough either).

 

[Doug71]

Afraid I don't do turning but it does machine well if a little brittle.

A quick Google brought up this

https://www.amazon.co.uk/Accoya-Fin...=sr_1_2?keywords=accoya&qid=1636324857&sr=8-2
I get it from Lavers but think Lathams etc stock it.

 

[Cabinetman]

I used it to turn a couple of finials once, turned well but the shavings stuck to everything including me, with static in a very peculiar manner.
From memory it’s guaranteed 25 years underground and 50 above. Ian

 

[Jones]

Standard reds will be available in the size needed and easy to turn. If you can send it back to the merchant and have them put it in their preservative tank it will last as well.

 

[Bob Chapman]

When I had my business I made dozens of replacement roof finials. The ones being replaced were mostly Victorian and mostly pitch pine. I also used reclaimed pitch pine from a firm a few miles away and never had any problems. No reason why they shouldn't last another 100 years or so.